WO2021121137A1 - 温度采样装置、温度保护装置及方法、以及照明系统 - Google Patents

温度采样装置、温度保护装置及方法、以及照明系统 Download PDF

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Publication number
WO2021121137A1
WO2021121137A1 PCT/CN2020/135541 CN2020135541W WO2021121137A1 WO 2021121137 A1 WO2021121137 A1 WO 2021121137A1 CN 2020135541 W CN2020135541 W CN 2020135541W WO 2021121137 A1 WO2021121137 A1 WO 2021121137A1
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Prior art keywords
temperature
signal
circuit
temperature sampling
module
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PCT/CN2020/135541
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English (en)
French (fr)
Inventor
周林
熊爱明
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嘉兴山蒲照明电器有限公司
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Priority to US17/785,796 priority Critical patent/US11991798B2/en
Publication of WO2021121137A1 publication Critical patent/WO2021121137A1/zh

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/10—Controlling the intensity of the light
    • H05B45/18—Controlling the intensity of the light using temperature feedback
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
    • H05B45/56—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits involving measures to prevent abnormal temperature of the LEDs
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
    • Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Definitions

  • This application relates to the technical field of temperature protection devices, and in particular to a temperature sampling device, a temperature protection device and method, and a lighting system.
  • LED lights used in outdoor lighting work at high power for a long time, and the temperature of the LED lights will continue to rise during use. When the temperature is too high, if no additional means are used to cool the LED lights, the LED lights are easy to burn. If the LED lamp for indoor lighting has insufficient heat dissipation space, it is easy to cause the LED lamp beads or the LED power supply to be damaged due to overheating due to the high temperature of the LED lamp, which affects the life of the LED driver.
  • the purpose of this application is to provide a temperature sampling device, a temperature protection device and method, and a lighting system.
  • the first aspect of the present application discloses a temperature sampling device, which includes a temperature detection unit and a signal processing unit.
  • the temperature detection unit has a detection terminal for the environmental temperature change of the circuit to be protected. And change its own resistance;
  • the signal processing unit is coupled to the detection terminal, and is used to limit the detection signal in the temperature detection unit that is affected by the resistance change, so as to output a value corresponding to the resistance change A temperature sampling signal; wherein the temperature sampling signal is formed when the detection signal is subject to the limitation; wherein the temperature sampling signal is used for transmission to a temperature protection device.
  • the temperature sampling signal is output when the ambient temperature reaches the initial protection temperature.
  • the signal processing unit transitions from the first state to the second state based on the change of the detection signal; wherein, during the second state, the signal processing unit generates The temperature sampling signal.
  • the temperature detection unit includes a thermistor and a voltage divider connected in series, and the detection terminal is located between the thermistor and the voltage divider.
  • the thermistor includes a variable resistor whose resistance changes in a positive direction as the ambient temperature changes.
  • the thermistor includes a variable resistor whose resistance changes negatively as the ambient temperature changes.
  • the signal processing unit includes: an amplifying module, the input terminal of which is coupled to the detection terminal, the reference terminal of which is connected to the first reference signal, and the output terminal of which outputs the Temperature sampling signal; and a feedback module, coupled between the detection terminal and the output terminal of the amplifying module, for feeding back a feedback signal formed according to the temperature sampling signal to the detection terminal to limit the The change in the detection signal; wherein the amplification module amplifies the signal received by the input terminal based on the limited detection signal to output the temperature sampling signal.
  • the feedback module is configured to determine that the resistance change range of the temperature detection unit corresponds to a preset signal quantity change range of the temperature sampling signal.
  • the amplifying module includes a triode connected to the circuit between the reference terminal and the output terminal of the amplifying module, and the control terminal of which is coupled to the input terminal of the amplifying module.
  • the amplifying module includes at least two cascaded triodes, the control end of the first triode is coupled to the detection end, and the last triode is connected to the amplifying module In the circuit between the reference terminal and the output terminal.
  • the amplifying module includes an operational amplifier, two input terminals of which are respectively coupled to the input terminal and the reference terminal of the amplifying module, and the output terminal of the operational amplifier is coupled to The output terminal of the amplifying module.
  • the temperature sampling device further includes an output unit coupled to the output terminal of the signal processing unit to output the temperature sampling signal.
  • the output unit includes: a voltage follower module, the input terminal of which is coupled to the output terminal of the signal processing unit, the reference terminal receives a second reference signal, and the voltage follower module The output terminal of the module outputs the temperature sampling signal.
  • the voltage follower module includes: a triode connected between the input terminal and the reference terminal of the voltage follower module, the triode is also connected to the output of the voltage follower module Terminal to output the temperature sampling signal.
  • the temperature sampling device further includes a filtering unit, coupled to the output end of the signal processing unit, for signal filtering.
  • the circuit to be protected includes at least one of the following: a switching power supply, an electronic component whose efficiency is reduced/lost due to heat, or an LED load circuit.
  • a second aspect of the present application discloses a temperature protection device, comprising: a temperature sampling device and a temperature protection unit as disclosed in any embodiment of the first aspect, the temperature sampling device is used to detect the ambient temperature of the circuit to be protected and output temperature samples Signal, the temperature protection unit is coupled to the temperature sampling device to obtain the temperature sampling signal, and provides a temperature protection operation corresponding to the environmental temperature change for the circuit to be protected.
  • the circuit to be protected includes: a switching power supply, an electronic component whose efficiency is reduced/lost due to heat, or an LED load circuit.
  • the temperature protection unit includes a load driving module coupled to the temperature sampling device; the temperature protection operation includes: performing a reduction to the load according to the temperature sampling signal Operation of output power.
  • the driving module includes: a driving control circuit with a feedback pin, and the temperature sampling signal is transmitted to the feedback pin.
  • the driving module includes: a circuit structure constructed based on the BUCK circuit architecture, a circuit structure constructed based on the BOOST circuit architecture, and a circuit constructed based on the BOOST-BUCK circuit architecture Any of the structures.
  • the temperature sampling signal is different from the feedback signal obtained by the driving module and reflecting the power supply of the load.
  • the drive module further includes a switch circuit, and the control signal output by the drive control circuit to the switch circuit changes with the change of the temperature sampling signal.
  • the temperature protection unit includes a heat dissipation module, which is provided at the circuit to be protected and coupled to the temperature sampling device; the heat dissipation module samples the temperature according to the temperature The signal performs a cooling operation.
  • the temperature protection device is provided in an LED lighting system.
  • the temperature protection unit includes a dimming module, which is coupled to the temperature sampling device; the dimming module is configured to output a dimming module according to the temperature sampling signal.
  • the dimming signal of the brightness of the LED load circuit in the LED lighting system is coupled to the temperature sampling device; the dimming module is configured to output a dimming module according to the temperature sampling signal.
  • the LED lighting system includes: a lighting system with an output power higher than 30W.
  • a third aspect of the present application discloses an LED lighting system, including: the temperature sampling device disclosed in any embodiment of the first aspect, an LED load circuit, and a switching power supply, the LED load circuit is driven by a DC power supply, and the switching power supply Is coupled to the LED load circuit for converting an AC signal provided by an external AC power supply into a power supply signal of the LED load circuit, and the switching power supply is also coupled to the temperature sampling device, according to the The temperature sampling signal provided by the temperature sampling device performs an operation to reduce the output power to the LED load circuit.
  • the switching power supply includes: a rectifier module for rectifying the AC signal and outputting a rectified signal; a filter module, coupled to the rectifier module, for The rectified signal is filtered and output; a drive module, coupled to the filter module, is used to perform energy conversion on the filtered rectified signal to supply power to the LED load; wherein, the drive module is also coupled to The temperature sampling device performs an operation of reducing the output power to the LED load circuit according to the temperature sampling signal.
  • the driving module includes: a driving control circuit with a feedback pin, and the temperature sampling signal is output to the feedback pin.
  • the driving module includes: a circuit structure based on the BUCK circuit architecture, a circuit structure based on the BOOST circuit architecture, and a circuit based on the BOOST-BUCK circuit architecture Any of the structures.
  • the temperature sampling signal is different from the feedback signal obtained by the driving module and reflecting the power supply of the LED load circuit.
  • the drive module further includes a switch circuit, and the control signal output by the drive control circuit to the switch circuit changes with the change of the temperature sampling signal.
  • the LED lighting system further includes a start-up protection circuit, which is coupled between the detection terminal of the temperature detection unit in the temperature sampling device and the reference terminal that provides the first reference signal , Used for starting protection of the LED load circuit according to the temperature sampling signal when the LED lighting system is powered on.
  • the LED lighting system includes: a lighting system with an output power higher than 30W.
  • the fourth aspect of the present application discloses a temperature collection method, which is applied to a temperature sampling device, wherein the temperature sampling device includes a circuit that changes resistance with changes in ambient temperature, and the temperature collection method includes: In the temperature sampling device, a detection signal affected by the change in the resistance value; output a temperature sampling signal corresponding to the change in the resistance value; wherein the temperature sampling signal is when the detection signal is restricted Forming.
  • a fifth aspect of the present application discloses a temperature protection method, including the following steps: limiting the detection signal in the temperature sampling device that is affected by the resistance change; outputting a temperature sampling signal corresponding to the resistance change; wherein The temperature sampling signal is formed under the condition that the detection signal is subject to the limitation; the temperature protection operation of the LED lamp is performed based on the temperature sampling signal.
  • the step of performing a temperature protection operation on the LED lamp based on the temperature sampling signal includes at least one of the following: making the switching power supply in the LED lamp based on the temperature The sampling signal reduces the output power supply; the dimming module in the LED lamp adjusts the output dimming signal based on the temperature sampling signal to reduce the brightness of the LED lamp when the temperature rises; or it is set at all
  • the heat dissipation device at the circuit to be protected of the LED lamp performs a heat dissipation operation based on the temperature sampling signal.
  • the temperature sampling device, temperature protection device and method, and lighting system disclosed in the present application sense the ambient temperature of the LED load circuit through the thermistor, and achieve the effect of cooling the LED load circuit by reducing the output power.
  • Low cost, energy saving and safe in addition, the temperature sampling device can be directly coupled with the pins of the switching power supply in the existing LED lighting system, and there is no need to modify the circuit of the switching power supply in the LED lighting system.
  • the temperature protection function can be realized without additional design of a suitable circuit or chip, and the versatility is strong.
  • FIG. 1 shows a schematic block diagram of the circuit in an embodiment of the temperature sampling device of the present application
  • FIG. 2 shows a schematic diagram of the circuit structure of a temperature detection unit in an embodiment of the temperature sampling device of the present application
  • FIG. 3 shows a schematic diagram of the circuit structure of the temperature detection unit in another embodiment of the temperature sampling device of the present application
  • FIG. 4 shows a schematic block diagram of a circuit of a signal processing unit in an embodiment of the temperature sampling device of the present application
  • FIG. 5 shows a schematic diagram of a circuit structure of a signal processing unit in an embodiment of the temperature sampling device of the present application
  • FIG. 6 shows a schematic diagram of the circuit structure of the signal processing unit in another embodiment of the temperature sampling device according to the present application.
  • Fig. 7 shows a schematic diagram of the variation curve between the resistance value Rfb of the feedback module and the signal quantity variation range of the temperature sampling signal Vtem;
  • FIG. 8 shows a circuit block diagram of the temperature sampling device according to another embodiment of the present application.
  • FIG. 9 shows a schematic diagram of a circuit structure of a voltage follower module in an embodiment of the temperature sampling device of the present application.
  • FIG. 10 shows a schematic diagram of the circuit structure of the voltage follower module in another embodiment of the temperature sampling device according to the present application.
  • FIG. 11 shows a circuit block diagram of the temperature sampling device according to another embodiment of the present application.
  • FIG. 12A shows a circuit block diagram of the temperature sampling device according to another embodiment of the present application.
  • FIG. 12B shows a schematic diagram of the circuit structure of a temperature protection circuit according to an embodiment of the present invention
  • FIG. 12C shows a schematic diagram of the circuit structure of a temperature protection circuit according to another embodiment of the present invention.
  • FIG. 12D shows a schematic diagram of the relationship curve between the temperature protection signal Vtem and RNTC according to an embodiment of the present invention
  • FIG. 13 shows a circuit block diagram of an embodiment of the temperature protection device of the present application
  • FIG. 14 shows a schematic diagram of a circuit structure of a driving module in an embodiment of the temperature protection device of the present application
  • FIG. 15 shows a schematic diagram of the circuit structure of the driving module of the temperature protection device according to another embodiment of the present application.
  • FIG. 16 shows a schematic diagram of the circuit structure of the driving module of the temperature protection device according to another embodiment of the present application.
  • FIG. 17 shows a schematic diagram of the circuit structure of the driving module of the temperature protection device according to another embodiment of the present application.
  • FIG. 18 shows a schematic diagram of the circuit structure of the driving module of the temperature protection device according to another embodiment of the present application.
  • FIG. 19 shows a schematic diagram of the circuit structure of the driving module of the temperature protection device according to another embodiment of the present application.
  • FIG. 20 shows a circuit block diagram of an embodiment of the LED lighting system of this application.
  • FIG. 21 shows a circuit block diagram of a switching power supply in an embodiment of the LED lighting system of this application.
  • FIG. 22 shows a schematic diagram of a circuit structure of a rectifier module in an embodiment of the LED lighting system of this application
  • FIG. 23 shows a schematic diagram of a circuit structure of a filter module in an embodiment of the LED lighting system of this application.
  • FIG. 24 shows a schematic diagram of the circuit structure of the filter module in another embodiment of the LED lighting system of this application.
  • FIG. 25 shows a schematic diagram of the structure of an LED load circuit in an embodiment of the LED lighting system of this application.
  • FIG. 26 shows a schematic structural diagram of an LED load circuit in another embodiment of the LED lighting system of this application.
  • FIG. 27 shows a circuit block diagram of the startup protection circuit in an embodiment of the LED lighting system of this application.
  • FIG. 28 shows a schematic diagram of the circuit structure of the startup protection circuit in an embodiment of the LED lighting system of this application.
  • FIG. 29 shows a flow chart of an embodiment of the temperature collection method of this application.
  • FIG. 30 shows a flow chart of an embodiment of the temperature protection method of the LED lamp of this application.
  • Figure 31 shows a schematic diagram of the thermistor resistance changing linearly with temperature.
  • first, second, etc. are used herein to describe various elements or parameters in some examples, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter.
  • the first input terminal may be referred to as the second input terminal, and similarly, the second input terminal may be referred to as the second input terminal without departing from the scope of the various described embodiments.
  • the first input terminal and the second input terminal are both describing one input terminal, but unless the context clearly indicates otherwise, they are not the same input terminal. Similar situations also include the first rectified output terminal and the second rectified output terminal, or the first filtered output terminal and the second filtered output terminal.
  • A, B or C or "A, B and/or C” means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C” .
  • An exception to this definition will only occur when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way.
  • the application range of electronic components is very wide, not only in general industry, but also in transportation, household appliances, and power supplies for electronic devices.
  • heat will be generated.
  • the heat accumulates and the temperature is too high, it is easy to cause the life of the electronic components to be reduced, or to make some temperature-sensitive electronic components fail, thereby affecting the normal operation of the entire electronic device.
  • the lighting equipment that occupies a prominent position in household appliances, when it works beyond the safety threshold, not only the life of the light source itself will be greatly reduced, but also the performance of the driver driving the light source will be degraded or even damaged.
  • Electronic components are components of electronic components and small machines and instruments. They are often composed of several parts. Electronic components include: resistors, capacitors, inductors, potentiometers, electron tubes, radiators, electromechanical components, and connectors. , Semiconductor devices, electro-acoustic devices, laser devices, electronic display devices, optoelectronic devices, sensors, power supplies, switches, electronic transformers, relays, integrated circuits, various circuits, etc.
  • a switching power supply As an example, it is used as a device for power conversion to convert AC power provided by the mains power into low-voltage DC power, which can be, for example, a power adapter, a driver, or a driving chip of an electronic device.
  • the electronic components in the switching power supply may be degraded or lose efficiency due to heat. For example, the electrolyte in an electrolytic capacitor will dry up due to the high temperature, and the capacity of the electrolytic capacitor will decrease or fail.
  • the electrolytic capacitor with a limit operating temperature of 85°C as an example, when it works at a temperature of 20°C In general, it can guarantee a normal working time of 181019 hours, and when working at a limit temperature of 85°C, it can only guarantee a normal working time of 2000 hours in general.
  • the volt-ampere characteristics of a diode change due to temperature. Taking the room temperature 26°C as a reference, when the diode forward current remains unchanged, the forward voltage drop decreases by 2 ⁇ 2.5mV for every 1°C increase in temperature. , The reverse current will be doubled for every 10°C increase in temperature.
  • the insulation performance of inductors, transformers, chokes, etc. will decrease as the temperature rises.
  • the LED load circuit includes a plurality of LED lamp beads. When the temperature of the LED lamp beads exceeds 100° C., the working life of the LED lamp beads will be greatly reduced.
  • this application proposes a temperature sampling device, a temperature protection device and method, and a lighting system to solve the aforementioned problems.
  • a temperature sampling device a temperature protection device and method
  • a lighting system to solve the aforementioned problems.
  • the following combination The drawings illustrate the specific embodiments of the application in detail. The following descriptions of the embodiments of the present application are for illustrative purposes only, and are not meant to represent all the embodiments of the present application or limit the present application to specific embodiments.
  • the same element numbers can be used to represent the same, corresponding or similar elements, and are not limited to represent the same elements.
  • this application proposes a temperature sampling device, and the proposed temperature sampling device will be described in detail below with reference to FIGS. 1 to 12C.
  • FIG. 1 shows a circuit block diagram of an embodiment of the temperature sampling device of the present application.
  • the temperature sampling device 20 includes a temperature detection unit 21 and a signal processing unit 22.
  • the temperature detection unit 21 has a detection terminal Pi_210, and the temperature detection unit 21 changes its own resistance under the influence of the environmental temperature change of the circuit to be protected (not shown) to output the detection signal Vdec at the detection terminal Pi_210.
  • the signal processing unit 22 is coupled to the detection terminal Pi_210, and is used to limit the detection signal Vdec in the temperature detection unit 21 that is affected by the resistance change, so as to output the temperature corresponding to the resistance change on the signal output terminal Pi_220 of the signal processing unit 22 Sample signal Vtem.
  • the circuit to be protected refers to a circuit structure built by electronic components, which can change its own circuit characteristics, reduce circuit life, or damage circuit functions under the influence of temperature, where the electronic components include but are not limited to: resistors , Capacitors, inductors and other basic components, as well as semiconductor devices such as power tubes, integrated circuits.
  • the circuit to be protected is exemplified by at least one of the aforementioned switching power supply, electrolytic capacitor, and LED load circuit.
  • the temperature detection unit 21 is integrally arranged near the circuit to be protected, or the thermal element in the temperature detection unit 21 is arranged near the circuit to be protected, so as to sense the temperature of the circuit to be protected.
  • the temperature detection unit 21 has the characteristic of changing its conductivity (conductivity reflects the change of resistance value) as the temperature of the environment changes.
  • the detection signal Vdec output by the temperature detection unit 21 may have the characteristics of monotonically changing with linear changes in temperature, or may appear at a certain temperature. Under the surge characteristics. To this end, the detection signal Vdec output by the temperature detection unit 21 reflects a change in temperature or a certain specific temperature.
  • the monotonicity may be monotonicity based on a linear relationship, or monotonicity based on a non-linear relationship.
  • the change in the resistance of the temperature detection unit 21 and the change in the ambient temperature have a coefficient K proportional relationship.
  • Figure 31 shows a schematic diagram of the thermistor resistance changing linearly with temperature.
  • the resistance change of the temperature detection unit 21 and the change of the ambient temperature are non-linear, and when the ambient temperature is different In the interval, the resistance of the temperature detection unit 21 varies with the temperature.
  • the temperature detection unit 21 The resistance value changes significantly with temperature.
  • the ambient temperature is in the normal range (between 30°C and 60°C in FIG. 31)
  • the resistance value of the temperature detection unit 21 does not change significantly with temperature.
  • the relationship between the resistance change of the temperature detection unit 21 and the ambient temperature change is in the same direction, for example, as the ambient temperature increases, the resistance increases, or as the ambient temperature decreases.
  • the resistance value decreases; in another example, the relationship between the resistance value change of the temperature detection unit 21 and the ambient temperature change is reversed, for example, as the ambient temperature rises, the resistance value decreases, or with As the ambient temperature decreases, the resistance increases.
  • the above monotonicity is not necessarily applicable or measurable in all temperature ranges.
  • the change in the resistance of the temperature detection unit 21 can be ignored, or the temperature detection unit 21 is used as a circuit structure with a fixed resistance; when When the ambient temperature of the LED lamp beads reaches a certain temperature range above the corresponding threshold temperature, the characteristic that the resistance value presented by the temperature detection unit 21 changes monotonously with temperature changes is easier to measure.
  • the above-mentioned circuit characteristic that has a monotonicity between the change in resistance value and the change in ambient temperature can be regarded as the circuit characteristic exhibited at least during the normal operation of the temperature protection circuit.
  • FIG. 2 shows a schematic diagram of the circuit structure of the temperature detection unit in an embodiment of the temperature sampling device of this application.
  • the temperature detection unit 21 includes a thermistor R21_2 and a voltage dividing resistor R21_1 connected in series, so One end of the thermistor R21_2 is coupled to the detection terminal Pi_210, the other end is grounded to GND, one end of the voltage divider R21_1 is coupled to the power supply VCC, and the other end is coupled to one end of the thermistor R21_2.
  • the thermistor R21_2 is a negative temperature coefficient thermistor (Negative Temperature Coefficient, NTC).
  • NTC Negative Temperature Coefficient
  • the working principle of the temperature detection unit 21 is: when the ambient temperature rises The resistance of the thermistor R21_2 is reduced by the increase in ambient temperature.
  • the detection signal Vdec on the detection terminal Pi_210 is the partial voltage of the power supply VCC obtained by the thermistor R21_2. Due to the decrease in the resistance of the thermistor R21_2, the detection signal Vdec decreases; correspondingly, when the ambient temperature decreases, the detection signal Vdec increases.
  • the thermistor R21_2 is a positive temperature coefficient thermistor (PTC).
  • the working principle of the temperature detection unit 21 is: when the ambient temperature rises When the thermistor R21_2 increases in resistance due to the increase in ambient temperature, the detection signal Vdec on the detection terminal Pi_210 is the partial voltage of the power supply Vcc obtained by the thermistor R21_2. Due to the increase in the resistance of the thermistor R21_2, Therefore, the detection signal Vdec increases; correspondingly, when the ambient temperature decreases, the detection signal Vdec decreases.
  • FIG. 3 shows a schematic diagram of the temperature detection unit circuit structure in another embodiment of the temperature sampling device of this application.
  • the temperature detection unit 21 includes a thermistor R21_3 and a voltage divider resistor R21_4 connected in series.
  • One end of the thermistor R21_3 is coupled to the detection terminal Pi_210, the other end is connected to the power supply Vcc, one end of the voltage divider R21_4 is grounded to GND, and the other end is coupled to one end of the thermistor R21_3.
  • the thermistor R21_3 is a negative temperature coefficient thermistor NTC.
  • the working principle of the temperature detection unit 21 is: when the ambient temperature rises, the thermistor R21_3 is The resistance value is reduced when the ambient temperature rises.
  • the detection signal Vdec on the detection terminal Pi_210 is the voltage divider resistor R21_4 to obtain the voltage division of the power supply VCC.
  • the thermistor R21_3 is a positive temperature coefficient thermistor PTC. According to the circuit structure shown in FIG.
  • the working principle of the temperature detection unit 21 is: when the ambient temperature rises, the thermistor R21_3 The resistance value is increased due to the increase of the ambient temperature, the detection signal Vdec on the detection terminal Pi_210 is the voltage divider R21_4 to obtain the divided voltage of the power supply Vcc, due to the total resistance (the resistance value of the voltage divider 214 and the thermistor R21_3 The sum of the resistance values) increases, so the divided voltage of the power supply Vcc obtained by the voltage dividing resistor R21_4 decreases, so the detection signal Vdec decreases; correspondingly, when the ambient temperature decreases, the detection signal Vdec increases.
  • the thermistor R21_2 or R21_3 in the temperature detection unit 21 has the characteristic of changing the resistance value with temperature changes, so that the detection signal Vdec changes monotonously with the change of the resistance value of the temperature detection unit 21.
  • the detection terminal Pi_210 of the temperature detection unit 21 is also coupled There is a signal processing unit 22, and the signal processing unit 22 is used to limit the detection signal Vdec in the temperature detection unit 21 that is affected by the resistance value change, so that the output corresponding to the resistance value change when the detection signal Vdec is limited The temperature sampling signal Vtem.
  • the signal processing unit 22 limits the change range of the detection signal Vdec, so that within the same environmental temperature change range, the signal amount change range of the detection signal Vdec is reduced from the unrestricted [a1,b1] range to the restricted [a1,b1] range. c1,d1] range. Measured at the macro level, the narrowed signal volume change range [c1, d1] can be regarded as basically unchanged. The narrowed signal amount change range may not be easily detected, but the signal processing unit 22 will respond.
  • the signal processing unit 22 performs signal processing on the limited detection signal Vdec, so that the temperature sampling signal Vtem output by the temperature sampling device still has a monotonicity between the change of the temperature sampling signal Vtem and the change of the resistance value.
  • the monotonicity indicates that the relationship between the change in the resistance of the temperature detection unit 21 and the change in the temperature sampling signal Vtem is in the same direction or in the reverse direction.
  • the relationship between the change in resistance and the change in temperature sampling signal Vtem is in the same direction. For example, as the resistance increases, the temperature sampling signal Vtem increases, or as the resistance decreases, the temperature sampling The signal Vtem decreases; in another example, the relationship between the resistance change and the temperature sampling signal Vtem change is reversed, for example, as the resistance increases, the temperature sampling signal Vtem decreases, or as the resistance increases As the value decreases, the temperature sampling signal Vtem increases.
  • the signal processing unit 22 includes an amplification module 222 and a feedback module 221.
  • the amplifying module 222 has an input terminal Pi_221, a reference terminal Pi_222, and an output terminal Pi_220.
  • the input terminal Pi_221 is coupled to the detection terminal Pi_210 of the temperature detection unit, and the reference terminal Pi_222 is connected to the first reference signal Vref1, and its output terminal is
  • the output terminal Pi_220 of the signal processing unit 22 is used to output a temperature sampling signal Vtem.
  • the feedback module 221 is coupled between the output terminal Pi_220 and the detection terminal Pi_210.
  • the feedback module 221 feeds back the feedback signal FB formed according to the temperature sampling signal Vtem to the detection terminal Pi_210 to limit the change of the detection signal Vdec.
  • the amplifying module 222 responds to the limited detection signal Vdec based on the limited detection signal Vdec.
  • the signal received by the input Pi_221 is amplified to output the temperature sampling signal Vtem.
  • the signal received by the input terminal Pi_221 is, for example, a current signal formed based on the limited detection signal Vdec, and the first reference signal Vref1 is a reference low potential, for example, the power ground GND or the reference ground SGND.
  • the temperature sampling signal Vtem is formed after the detection signal Vdec is limited by the feedback module 221, so that according to the feedback module 221, it can be determined that the resistance change range of the temperature detection unit 21 corresponds to the preset signal quantity of the temperature sampling signal.
  • the feedback module 221 is, for example, a resistor (not shown).
  • the feedback signal FB formed by the feedback module 221 according to the temperature sampling signal Vdec is the current of the temperature sampling signal Vdec flowing through the resistor. . Therefore, please refer to FIG. 7, which shows a schematic diagram of the variation curve between the resistance value Rfb of the feedback module and the signal quantity variation range of the temperature sampling signal Vtem.
  • the resistance value Rfb when the feedback module 221 is a resistor is related to The variation range of the preset temperature sampling signal Vtem corresponding to the variation range of the resistance value of the temperature detection unit 21, please refer to Fig. 2, Fig. 3, and Fig. 4, so that the ambient temperature of the circuit to be protected is between 80°C and 100°C
  • the thermistor R21_2 in the temperature detection unit 21 is NTC (or the thermistor R21_3 is PTC), and the resistance of the thermistor R21_2 (or the thermistor R21_3) varies in the range of 12K ⁇ -6.5K ⁇ .
  • the feedback module 221 When the resistance value of the resistance of the feedback module 221 is 100K ⁇ , the preset signal quantity of the temperature sampling signal varies from 0.5V to 7.2V; when the resistance value of the feedback module 221 is 150K ⁇ , the preset The change range of the signal quantity of the temperature sampling signal is 0.6V-8.5V; when the resistance of the feedback module 221 is 200K ⁇ , the preset change range of the signal quantity of the temperature sampling signal is 0.7V-9V.
  • the feedback module 221 also includes a circuit structure in which a plurality of resistive devices are equivalent to a resistance.
  • the feedback module 221 includes a plurality of series/parallel resistors. In this case, the feedback module 221 The equivalent resistance value of is related to the signal quantity change range of the preset temperature sampling signal corresponding to the resistance change range of the temperature detection unit 21.
  • FIG. 5 shows a schematic diagram of the circuit structure of the signal processing unit in an embodiment of the temperature sampling device of the present application.
  • the signal processing unit includes a feedback module 221, an amplification module 222, and a resistor R222_1.
  • One end of the feedback module 221 is coupled to the output terminal Pi_220 of the amplifying module 222, and the other end is coupled to the input terminal Pi_221.
  • the amplifying module 222 includes a transistor Q1, the first end of the transistor Q1 is coupled to the output terminal Pi_220, the second end of the transistor Q1 is coupled to the reference terminal Pi_222, and the control terminal is coupled to the input terminal Pi_221, in order to supply power to the amplifying module 222 and
  • the output terminal Pi_220 can normally output the temperature sampling signal Vtem, and the first terminal of the transistor Q1 is also coupled to a power supply Vcc via the resistor R222_1.
  • a resistor R222_2 can also be coupled between the control terminal of the transistor Q1 and the input terminal Pi_221 of the amplifying module 222 to protect the transistor Q1 from a large current impact.
  • a resistor R222_3 can also be coupled between the second terminal of the transistor Q1 and the reference terminal Pi_222 to stabilize the static operating point of the transistor Q1.
  • the resistor R222_2 and the resistor R222_3 are unnecessary components, they are shown in dashed lines in Figure 5, and the resistance of the resistor R222_3 is negligible compared to the resistor R222_1.
  • the resistor R222_3 is ohmic, and The resistance R222_1 is of the kiloohm level.
  • the transistor Q1 can adopt NPN type or PNP type.
  • the transistor Q1 shown is of the NPN type.
  • the transistor Q1 The PNP type can be used.
  • connection mode of the transistor Q1 in Figure 5 needs to be adjusted adaptively according to the connection mode of the PNP type triode.
  • those skilled in the art can select the model of the transistor Q1 according to the circuit architecture of the temperature sampling unit 21.
  • the temperature detection unit 21 adopts the circuit structure shown in FIG. 2 and the thermistor R21_2 adopts NTC as an example, and the working process of the signal processing unit 22 is described in conjunction with FIG. 5.
  • the feedback module 221 is coupled between the output terminal Pi_220 and the input terminal Pi_221 to limit the change of the detection signal Vdec. Taking the feedback module 221 as a resistor as an example, it uses the acquired temperature sampling signal Vdec to flow through the resistor as the feedback signal FB, and feeds it back to the detection terminal Pi_210 of the temperature detection unit 21 through the input terminal Pi_221 of the amplifying module 222.
  • the temperature sampling signal Vtem becomes larger, the current as the feedback signal FB also increases, so that the current flowing through the thermistor R21_2 increases, thereby limiting the instantaneous decrease of the aforementioned detection signal Vdec. That is, in the above process, ignoring the control current Ib of the transistor Q1 (because the control current Ib is small), then the sum of the current flowing through the feedback module 221 and the current flowing through the resistor R21_1 of the temperature detection unit 21 and the current flowing through the thermistor The current of resistor R21_2 is equal, the equation Yes, where R221 is the resistance of the feedback module 221, ignoring the small change in the detection signal Vdec in the above process, then in the above process, as the resistance of the thermistor R21_2 decreases (or increases), the temperature sampling signal Vtem also Then increase (or decrease) within the preset change range.
  • the above description is only an example of using NTC for the thermistor R21_2 in the circuit architecture shown in FIG. 2.
  • the thermistor R21_2 is a PTC
  • the working principle of the signal processing unit 22 is similar to the above. The only difference is that the following As the resistance of the thermistor R21_2 decreases (or increases), the temperature sampling signal Vtem also decreases (or increases) within a preset variation range.
  • the temperature detection unit 21 can also adopt the circuit structure shown in FIG. 3.
  • the working principle of the signal processing unit 22 is similar to the above. The only difference is that the thermistor R21_3 adopts PTC. As the resistance of the thermistor R21_3 decreases (or increases), the temperature sampling signal Vtem also increases (or becomes smaller) within the preset variation range. When the thermistor R21_3 uses NTC, the temperature sampling signal Vtem will increase (or decrease). As the resistance of the resistor R21_3 decreases (or increases), the temperature sampling signal Vtem also decreases (or increases) within a preset variation range.
  • the amplifying module 222 in the embodiment shown in FIG. 5 is used to amplify the control current Ib, since the control current Ib is relatively small, the temperature sampling signal Vtem output by the amplifying module 222 due to insufficient magnification varies with temperature.
  • the change of the resistance of the detection unit 21 is not obvious, which is not conducive to the temperature protection device to capture or perform the corresponding temperature protection operation according to the signal amount of the temperature sampling signal. Therefore, in another embodiment, in order to increase the magnification, the amplifying module in the signal processing unit includes at least two cascaded triodes, the control end of the first triode is coupled to the detection end, and the last triode is It is connected to the circuit between the reference terminal and the output terminal of the amplifying module.
  • FIG. 6 shows a schematic diagram of the circuit structure of the signal processing unit in another embodiment of the temperature sampling device of this application.
  • the signal processing unit includes a feedback module 221, an amplification module 222, a resistor R222_4, and Resistance R222_5.
  • One end of the feedback module 221 is coupled to the output terminal Pi_220 of the amplifying module 222, and the other end is coupled to the input terminal Pi_221.
  • the amplifying module 222 includes two cascaded transistors Q2 and Q3, wherein the transistor Q2 is the first-stage transistor, and the transistor Q3 is the last-stage transistor.
  • the first end of the transistor Q3 is coupled to the output terminal Pi_220 of the amplifying module 222, the second end of which is coupled to the reference terminal Pi_222 of the amplifying module 222, and the transistor Q3 is coupled to the second end of the transistor Q2 through its control end.
  • the control terminal of the transistor Q2 is coupled to the input terminal Pi_221 of the amplifying module 222.
  • the first terminal of the transistor Q2 is coupled via a resistor R222_5 Connected to the power source Vcc, the first end of the transistor Q3 is also coupled to the power source Vcc via the resistor R222_4.
  • a resistor R222_6 can also be coupled between the control terminal of the transistor Q2 and the input terminal Pi_221 of the amplifying module 222 to protect the transistor Q2 from a large current impact.
  • a resistor R222_7 can also be coupled between the second terminal of the transistor Q3 and the reference terminal Pi_222 to stabilize the static operating point of the transistor Q3.
  • the resistor R222_6 and the resistor R222_7 are unnecessary components, they are shown in dashed lines in FIG. 6, and the resistance of the resistor R222_7 is negligible compared with the resistor R222_4. In terms of order of magnitude, the resistor R222_7 is ohmic, and The resistance R222_4 is of the kiloohm level.
  • the transistors Q2 and Q3 can be of NPN type or PNP type.
  • the transistors Q2 and Q3 shown are of NPN type.
  • the transistors Q2 and Q3 shown are of PNP type.
  • the circuit structure of the two-stage triode shown in FIG. 6 is only an example, and is not a limitation on the number of stages of the amplifying module 222. In practical applications, those skilled in the art can also appropriately increase the number of transistors between the transistor Q2 and the transistor Q3 according to requirements.
  • the working principle of the signal processing unit shown in FIG. 6 is the same as the working principle of the signal processing unit including the signal processing unit shown in FIG.
  • the temperature sampling device achieves the purpose of converting the resistance value that changes with temperature into a corresponding temperature sampling signal within a preset signal amount range.
  • the thermistor R21_2 in the temperature detection unit 21 is NTC, and the thermistor When the ambient temperature of R21_2 is lower, its resistance is higher, which makes the voltage value of the detection signal Vdec shown in Fig.
  • the transistor Q1 NPN type
  • the transistor Q1 NPN type
  • the transistor Q1 is completely When it is turned on, the power supply Vcc flows directly into the reference terminal Pi_222 through the resistor R222_1, the transistor Q1, and the resistor R222_3, the output of the output terminal Pi_220 is zero or approximately zero, and the feedback module 221 of the signal processing unit 22 has no restriction on the detection signal Vdec.
  • the detection signal Vdec is also reduced due to the reduction of the thermistor R21_2 so that the transistor Q1 is in an amplified state (for example, the detection signal Vdec is reduced to 0.6V)
  • the feedback module 221 limits the detection signal Vdec to, for example, 0.6V, and the output terminal Pi_220 outputs a temperature sampling signal Vtem corresponding to the change of the thermistor R21_2.
  • the temperature sampling signal Vtem does not change with the change of the resistance.
  • the change between the resistance of the thermistor R21_2 or R21_3 and the temperature is related to its type and performance. If the thermistor R21_2 or R21_3 is of the PTC type, the corresponding resistance change curve with temperature is opposite to Figure 31 , That is, the resistance of the PTC type thermistor increases with temperature.
  • the signal processing unit 22 includes the semiconductor device in the above three states, the semiconductor device will also switch between the three states according to the change of the received electrical signal. This enables the temperature sampling device to provide temperature sampling signals when the circuit to be protected needs to provide temperature protection.
  • the thermistor R21_2 is a PTC
  • the transistor Q1 is a PNP type.
  • the detection signal Vdec is also small, so that the transistor Q1 is in a saturated state and is completely turned on, the output of the output terminal Pi_220 is zero or approximately zero, and the signal processing unit 22 is in the first state.
  • the detection signal Vdec also rises due to the rise of the thermistor R21_2 so that the transistor Q1 is in an amplified state, and the signal processing unit 22 enters the second state.
  • the temperature acquisition unit 21 may also adopt the circuit structure shown in FIG. 3, and at this time, the working principle of the signal processing unit 22 is similar to the above, and will not be repeated here.
  • the working process of the signal processing unit 22 shown in FIG. 6 changing from the first state to the second state is similar to the working process of changing from the first state to the second state corresponding to the circuit architecture shown in FIG. 5, except that
  • the amplifying module 222 of FIG. 6 includes two cascaded transistors Q2 and Q3, the transistors Q2 and Q3 of FIG. 6 switch from the saturated state to the amplified state
  • the value of the detection signal Vdec is different from that in Fig. 5.
  • the detection signal Vdec is reduced to 1.2V so that the transistors Q2 and Q3 are in the amplified state, and the signal processing unit 22 enters the second state.
  • the feedback module 221 in FIG. 6 limits the detection signal Vdec to around 1.2V and outputs
  • the terminal Pi_220 outputs a temperature sampling signal Vtem corresponding to the resistance change of the temperature detection unit 21.
  • the temperature sampling signal output by the temperature sampling device will not trigger the subsequent temperature protection operation of the temperature protection device, such as the temperature sampling signal The signal type, signal value, etc. will not trigger the temperature protection operation; or, the temperature sampling device will not output the temperature sampling signal and will not trigger the temperature protection operation.
  • the initial protection temperature for example, 80°C
  • the temperature sampling device outputs a temperature sampling signal reflecting the temperature change.
  • the signal processing unit 22 in each of the foregoing embodiments transitions from the first state to the second state based on the change in the detection signal when the ambient temperature of the circuit to be protected changes to the initial protection temperature, and in the second state During this period, the signal processing unit 22 generates the temperature sampling signal Vtem.
  • the first state is a state in which the signal processing unit 22 has not been activated, or a state in which a valid output is not provided according to the off state/on state of the semiconductor device in the signal processing unit 22
  • the second state is the signal processing unit The state in which 22 is activated, or the state in which the semiconductor device in the signal processing unit 22 is in a linear amplification state and is in a state to provide effective output.
  • FIG. 8 shows a schematic circuit block diagram of the temperature sampling device of this application in another embodiment.
  • the temperature sampling device 20 further includes an output unit 23 on the basis of FIG. 1, and the output unit 23 is coupled to the signal processing unit
  • the output terminal Pi_220 of 22 outputs the received temperature sampling signal Vtem.
  • the output unit 23 can play a role in signal isolation between the temperature sampling device and the subsequent circuit, and it includes a circuit structure with an isolation function such as a capacitor or a triode.
  • the output unit 23 includes a voltage follower module (not shown), the input terminal of which is coupled to the output terminal of the signal processing unit, the reference terminal receives the second reference signal, and the voltage follower module The output terminal of the output terminal outputs the temperature sampling signal.
  • FIG. 9 shows a schematic diagram of the circuit structure of the voltage follower module in an embodiment of the temperature sampling device of this application.
  • the voltage follower module includes a voltage follower 231, and the first input of the voltage follower 231 The terminal serves as the input terminal Pi_230 of the voltage follower module and is coupled to the output terminal Pi_220 of the signal processing unit 22, and its second input terminal serves as the reference terminal Pi_231 of the voltage follower module, which is coupled to the output terminal of the voltage follower 231, and the voltage follower
  • the output of 231 is used as the second reference signal, and the output terminal of the voltage follower 231 is used as the output terminal Pi_232 of the voltage follower module.
  • the magnification of the voltage follower 231 is 1 or close to 1, so the output of the voltage follower module at the output terminal Pi_232 follows the voltage follower module at the input
  • the temperature sampling signal Vtem received by the terminal Pi_230 that is, the output on the output terminal Pi_232 is the same or similar to the temperature sampling signal Vtem received by the voltage follower module at the input terminal Pi_230, therefore, it is regarded as the voltage shown in Figure 9 here.
  • the temperature sampling signal Vtem is output on the follower module.
  • FIG. 10 shows a schematic diagram of the circuit structure of the voltage follower module in another embodiment of the temperature sampling device of this application.
  • the voltage follower module includes a transistor Q4, and the control terminal of the transistor Q4 is coupled to the voltage
  • the input terminal Pi_230 of the follower module the first terminal is coupled to the reference terminal Pi_231 of the voltage follower module to receive the power source Vcc as the second reference signal to supply power to the transistor Q4, and the second terminal of the transistor Q4 is connected to a reference low potential via a resistor R23_1 (
  • the reference low potential is the power ground GND or SGND, shown as the power ground GND in FIG. 10)
  • the second end of the transistor Q4 is coupled to the output terminal Pi_232 of the voltage follower module to output the temperature sampling signal Vtem.
  • the transistor Q4 receives at its control terminal the temperature sampling signal Vtem input from the input terminal Pi_230 of the voltage follower module.
  • the temperature sampling signal will cause the transistor to enter an amplified state.
  • the control terminal of the transistor Q4 is different from the second terminal.
  • the PN junction between is already in the conducting state, and the voltage drop is basically unchanged after the PN junction is conducting.
  • the signal of the second terminal changes with the temperature sampling signal Vtem. And change, so the temperature sampling signal Vtem is output at the output terminal Pi_232 of the voltage follower module.
  • FIG. 11 shows a circuit block diagram of a temperature sampling device according to another embodiment of the present application.
  • the temperature sampling device further includes a filter unit 24 on the basis of FIG.
  • the output terminal Pi_220 of the unit 22 is used to filter the temperature sampling signal Vtem to remove the noise of the temperature sampling signal Vtem.
  • the filter unit 24 may be, for example, a filter capacitor (not shown). One end of the filter capacitor is coupled to the output terminal Pi_220 of the signal processing unit 22, and the other end is coupled to a reference low potential.
  • the reference low potential can be It is the power ground GND or the reference ground SGND, which is shown as the power ground GND in the figure.
  • FIG. 12A shows a schematic circuit block diagram of the temperature sampling device of this application in another embodiment.
  • the temperature sampling device further includes a filter unit 24 on the basis of FIG. 10, coupled to the output unit
  • the output terminal Pi_232 of 23 is used to filter the temperature sampling signal Vtem output by the output unit 23 to remove the noise of the temperature sampling signal Vtem.
  • the filter unit 24 may be, for example, a filter capacitor (not shown).
  • One end of the filter capacitor is coupled to the output terminal Pi_232 of the output unit 23, and the other end is coupled to a reference low potential.
  • the reference low potential may be Power ground GND or reference ground SGND, shown as power ground GND in the figure.
  • the temperature sampling signal Vtem output by the temperature sampling device described in the foregoing embodiments is used to transmit to the temperature protection device, so that the temperature protection device can respond to the temperature sampling signal Vtem to cool the circuit to be protected.
  • the temperature protection device may be a cooling fan, which is activated according to the temperature sampling signal Vtem to dissipate heat from the protection circuit;
  • the temperature protection device is a drive module in the power supply, and the drive module adjusts it based on the size of the temperature sampling signal Vtem Output power to reduce heat generation, so as to ensure the normal operation of the circuit to be protected.
  • the temperature protection device can be any device that can adjust the ambient temperature of the circuit to be protected based on the temperature sampling signal Vtem.
  • the temperature sampling device proposed in the above embodiments uses the thermistor to sense the ambient temperature of the circuit to be protected, which is low in cost; in addition, the temperature sampling device can be directly coupled with the temperature protection device, and no additional circuit is required. , There is no need to change the internal structure of the existing temperature protection device, and it has strong versatility.
  • the switching power supply can be referred to as a power supply module
  • the LED load circuit can be referred to as an LED module
  • the temperature sampling device can be referred to as a temperature protection circuit
  • the temperature sampling signal Vtem can be referred to as a temperature protection signal Vtem.
  • the temperature coefficient thermistor can be referred to as NTC for short.
  • the temperature protection circuit 20 includes resistors R21_1, R221_1, R222_1, R222_2 and R222_3, a transistor Q1 and NTCR21_2.
  • the first pin of the resistor R21_1 is electrically connected to the first pin of the resistor R222_1, and the second pin of the resistor R21_1 is electrically connected to the first pin of the NTCR21_2.
  • the first pin of the resistor R221_1 and the first pin of the resistor R222_2 are electrically connected and connected to the second pin of the resistor R21_1.
  • the second pin of the resistor R222_1 is electrically connected to the second pin of the resistor R221_1.
  • the base (b pole) of the transistor Q1 is electrically connected to the second pin of the resistor R222_2, its collector (c pole) is electrically connected to the second pin of the resistor R221_1, and its emitter (e pole) is electrically connected To the first pin of resistor R222_3.
  • the second pin of the resistor R222_3 is electrically connected to the second pin of the NTCR21_2 and is electrically connected to the circuit node GND.
  • the first pin of the resistor R21_1 is electrically connected to the input terminal of the temperature protection circuit for receiving the voltage input signal Vcc, and the collector (c pole) of the transistor Q1 is electrically connected to the output terminal of the temperature protection circuit for outputting temperature Protection signal Vtem.
  • NTCR21_2 is a negative temperature coefficient thermistor, which has different resistance values at different temperatures. Among them, when the temperature is higher, the resistance value is smaller.
  • NTCR21_2 is used to sense temperature and convert the temperature change into its own resistance value change.
  • the resistance change of NTCR21_2 is reflected in the circuit and will affect the output temperature protection signal Vtem. Since the b-pole input impedance of the transistor Q1 is large, similar to the circuit principle of an operational amplifier, the b-pole of the transistor Q1 can be equivalent to a virtual break, and the voltage V1 at the first pin of the resistor R21_1 is approximately equal to the turn-on of the transistor Q1
  • the relationship between the voltage Von and the current of the circuit satisfies the following relationship:
  • the current I1 flowing through the resistor R21_1 plus the current I2 flowing through the resistor R221_1 is equal to the current I3 flowing through the NTCR21_2.
  • R21_1 is the resistance of resistor R21_1
  • R221_1 is the resistance of resistor R221_1
  • R21_2 is the resistance of NTCR21_2
  • Vtem is the temperature protection signal
  • Vcc is the input voltage signal of the temperature protection circuit 20
  • V1 is the second of the resistor R21_1
  • the node voltage at the pin. V1 is equal to the turn-on voltage of transistor Q1, which is about 0.6V.
  • FIG. 12D shows a schematic diagram of the relationship between the temperature protection signal Vtem and the RNTC according to an embodiment of the present invention.
  • the abscissa is the resistance of NTCR21_2
  • the ordinate is the temperature protection signal Vtem. It can be seen from the figure that when the resistance of NTC increases, the temperature protection signal Vtem decreases.
  • the resistor R21_1 is used to set the initial temperature at which the temperature protection circuit 20 starts to output the temperature protection signal Vtem.
  • resistor R21_1 and NTC satisfy the following relationship:
  • R ON is the resistance value of the NTC corresponding to the initial temperature
  • R21_1 is the resistance value of the resistor R21_1
  • Vcc is the input voltage
  • Von is the turn-on voltage of the transistor Q1, which is about 0.6V.
  • the initial temperature of the temperature protection circuit 20 starting to output the temperature protection signal Vtem can be set.
  • the temperature protection circuit 20 starts to output a temperature protection signal.
  • the sensed temperature signal of NTCR 21_2 can be converted into its own resistance value, and then the temperature signal is converted into a corresponding temperature protection signal Vtem through the temperature protection circuit 20.
  • the temperature protection circuit 20 includes resistors R21_1, R221_2, R222_5, R222_4, R222_6, R222_7, and R23_1, capacitors C25_1 and C24_1, transistors Q2, Q3 and Q4, and NTCR21_2.
  • the first pin of the resistor R21_1 is electrically connected to the first pin of the resistor R222_5 and the first pin of the resistor R222_4.
  • the first pin of NTCR21_2 is electrically connected to the second pin of the resistor R21_1, and the second pin of the NTCR21_2 is electrically connected to the circuit node GND.
  • the first pin of the resistor R221_2 is electrically connected to the first pin of the resistor R222_6 and is electrically connected to the second pin of the resistor R21_1.
  • the b pole of the transistor Q2 is electrically connected to the second pin of the resistor R222_6, and the c pole of the transistor Q2 is electrically connected to the second pin of the resistor R222_5.
  • the b pole of the transistor Q3 is electrically connected to the e pole of the transistor Q2, the c pole is electrically connected to the second pin of the resistor R222_4, and the e pole is electrically connected to the first pin of the resistor R222_7.
  • the second pin of the resistor R222_7 is electrically connected to the circuit node GND
  • the first pin of the capacitor C25_1 is electrically connected to the first pin of the resistor R221_2
  • the second pin is electrically connected to the circuit node GND.
  • the b pole of the transistor Q4 is electrically connected to the second pin of the electronic R221_2 and the second pin of the resistor R222_4, the c pole is electrically connected to the first pin of the resistor R21_1, and the e pole is electrically connected to the resistor R23_1.
  • the second pin of the resistor R23_1 is electrically connected to the second pin of the capacitor C24_1 and is electrically connected to the circuit node GND.
  • Vcc is the input voltage of the input terminal of the temperature protection circuit 20
  • Vtem is the temperature protection signal output by the temperature protection circuit 20
  • V1 is the node voltage at the second pin of the resistor R21_1
  • Vtem1 is the node voltage at the second pin of the resistor R222_4.
  • the temperature protection circuit 20 of this embodiment is used to collect the operating temperature of the LED lamp and convert the temperature signal into a temperature protection signal Vtem.
  • the difference is that a transistor Q3 is added in this embodiment.
  • the triode Q2 and the triode Q3 are used to realize two-stage amplification and increase the stability of the circuit.
  • the transistor Q4 and the resistor R23_1 form a voltage follower, and the temperature protection signal Vtem has a stronger driving capability than Vtem1.
  • the capacitor C24_1 is used to filter the temperature protection signal Vtem.
  • R21_1 is the resistance of resistor R21_1
  • R221_2 is the resistance of resistor R221_2
  • R21_2 is the resistance of NTCR21_2
  • Vtem1 is the node voltage at the second pin of resistor R222_4
  • Vcc is the input voltage signal of the temperature protection circuit 20
  • V1 is the voltage from the second pin of the resistor R21_1.
  • V1 is the sum of the turn-on voltages of the transistor Q2 and the transistor Q3, which is about 1.2V.
  • Vtem and Vtem1 are approximately equal.
  • the capacitor C25_1 is used to realize the slow start of the LED light, that is, the LED light slowly lights up after being powered on.
  • the time from power-on to the normal brightness of the LED light depends on the size of the capacitor C25_1. Among them, the smaller the value of the capacitor C25_1, the faster the LED light starts.
  • the thermistor NTCR21_2 can be replaced by the thermistor PTC.
  • the temperature protection signal Vtem has a negative correlation with the sampling temperature of the thermistor, that is, the higher the sampling temperature, the smaller the temperature protection signal Vtem.
  • this application also proposes a temperature protection device.
  • the temperature protection device 30 It includes a temperature sampling device 31 and a temperature protection unit 32.
  • the temperature sampling device 31 is used to detect the ambient temperature of the circuit to be protected (not shown) and output a temperature sampling signal Vtem.
  • the temperature protection unit 32 is coupled to the temperature sampling device 31 to obtain the temperature sampling signal Vtem, A temperature protection operation corresponding to the environmental temperature change is provided for the circuit to be protected.
  • the circuit to be protected refers to a circuit structure built by electronic components, which may change its own circuit characteristics, reduce circuit life, or damage circuit functions under the influence of temperature.
  • the electronic components include but are not limited to: Basic components such as resistors, capacitors, and inductors, as well as semiconductor devices such as power tubes and integrated circuits.
  • the switching power supply is used as a device for electrical energy conversion to convert AC power provided by the mains power into low-voltage DC power.
  • the switching power supply can be, for example, a power adapter, a driver, or a driving chip of an electronic device.
  • the electronic components in the switching power supply may be degraded or lose efficiency due to heat.
  • the electrolyte in an electrolytic capacitor will dry up due to the high temperature, and the capacity of the electrolytic capacitor will decrease or fail.
  • the LED load circuit includes a plurality of LED lamp beads. When the temperature of the LED lamp beads exceeds 100° C., the working life of the LED lamp beads will be greatly reduced.
  • the temperature sampling device 31 is arranged in the vicinity of the circuit to be protected as a whole, or the thermal element in the temperature detection unit 21 is arranged in the vicinity of the circuit to be protected to sense the temperature of the circuit to be protected.
  • the temperature sampling device 31 is shown in Figures 1 to 1 above.
  • the drive module is a device that converts an external input signal into an electrical signal suitable for load operation by controlling the conversion of electric energy
  • the load can be various electronic devices and household appliances.
  • the driving module is implemented by a switching power supply, a driving control circuit, or a driving control chip, wherein the driving control circuit has a feedback pin to receive the temperature sampling signal Vtem.
  • the drive module can also be other circuit structures that control the conversion of electrical energy.
  • the drive module can include a circuit structure based on the BUCK circuit architecture, a circuit structure based on the BOOST circuit architecture, and a circuit structure based on the BOOST circuit architecture. Any of the circuit structures constructed by BOOST-BUCK circuit architecture.
  • FIG. 14 shows a schematic diagram of the circuit structure of the driving module in an embodiment of the temperature protection device of this application.
  • the driving module includes a driving control circuit 321, and the driving control circuit 321 has a feedback pin. CS, output pin GT, and ground pin GND.
  • the ground pin GND of the drive control circuit 321 is coupled to the power ground GND.
  • the feedback pin CS is coupled to a load feedback terminal Pi_320 to receive the feedback signal Vfb reflecting the power supplied by the load, and on the other hand, it is coupled to the temperature sampling device 31
  • the output terminal Pi_310 (the output terminal Pi_310 may correspond to Pi_220 in FIGS. 1 to 6, and 11, or Pi_232 in FIGS.
  • the drive control circuit 321 outputs a control signal on its output pin GT according to the feedback signal Vfb and the temperature sampling signal Vtem, so that the controlled circuit reduces the load according to the control signal. power.
  • the controlled circuit is a circuit that is controlled by the drive control circuit 321 to provide power to the load.
  • the controlled circuit includes a switch circuit coupled to the output pin GT and a power converter coupled to the switch circuit The switch circuit is controlled by the driving control circuit 321 to switch on and off to control the power conversion circuit to perform energy conversion, so that the power conversion circuit outputs a load power supply signal to supply power to the load.
  • the switch circuit can also be used as a part of the driving module.
  • FIG. 15 shows a schematic diagram of the circuit structure of the driving module in another embodiment of the temperature protection device of this application.
  • the drive module further includes a switch circuit 322, which is coupled to the output pin GT of the drive control circuit 321, so that the drive control circuit 321 outputs a temperature-dependent sampling signal to the switch circuit 322 through its output pin GT.
  • the switching circuit 322 adjusts any one of its switching frequency, on-duration, or off-duration based on the control signal that Vtem changes, so as to achieve the effect of adjusting the load power.
  • the switch circuit 322 may include a switch, and the switch may be, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET), a bipolar junction transistor ( Bipolar Junction Transistor, BJT), triode, etc.
  • MOSFET metal-oxide-semiconductor field-effect transistor
  • BJT bipolar junction transistor
  • triode etc.
  • the power conversion circuit can also be divided into a part of the drive module.
  • FIG. 16 shows a schematic diagram of the circuit architecture of the drive module in another embodiment of the temperature protection device of this application.
  • the driving module includes a driving control circuit 321, a switch circuit 322, and a power conversion circuit 323.
  • the power conversion circuit 323 has a first pin Pi_321, a first output terminal Pi_322, and a second output terminal Pi_323, and receives an external power supply signal Vin (direct current signal) through its first pin Pi_321 to perform energy conversion.
  • the output terminal Pi_322 and the second output terminal Pi_323 output a load power supply signal Vout.
  • the power conversion circuit 323 is coupled to the switch circuit 322.
  • the switch circuit 322 is controlled by the drive control circuit 321.
  • the power conversion circuit 323 includes an inductor L323_1, a freewheeling diode D323_1, and a capacitor C323_1.
  • One end of the inductor L323_1 is connected to the second output terminal Pi_323, and the other end is coupled to the first end of the switch circuit 322.
  • the capacitor C323_1 is coupled between the first output terminal Pi_322 and the second output terminal Pi_323 to stabilize the voltage difference between the first output terminal Pi_322 and the second output terminal Pi_323.
  • the cathode of the freewheeling diode D323_1 is coupled to the first output terminal Pi_322, the anode is coupled to the first end of the switch circuit 322.
  • the switch circuit 322 includes a switch Q5, which has a first terminal, a second terminal, and a control terminal, and uses the first terminal of the switch Q5 as the first terminal of the switch circuit 322 to be coupled to the inductor L323_1 of the power conversion circuit 323
  • the second end of the switch Q5 is connected to the power ground GND via a sampling resistor Rcs_1, and the control end of the switch Q5 is coupled to the output pin GT of the drive control circuit 321.
  • the sampling resistor Rcs_1 arranged between the second end of the switch Q5 and the power ground GND is used to form a current detection circuit that converts the current flowing through the switch Q5 into a voltage value to form the feedback signal Vfb.
  • the feedback signal Vfb on the current detection circuit can be collected and transmitted to the drive control circuit 321 via the load feedback terminal Pi_320.
  • the drive control circuit 321 determines the on and off timing of the switch Q5 according to the temperature sampling signal Vtem and the feedback signal Vfb.
  • the drive control circuit 321 controls the switch Q5 to turn on
  • the external power supply signal Vin flows in through the first pin Pi_321, and flows out from the switch Q5 through the capacitor C323_1 and the first output terminal Pi_322 to the second output terminal Pi_323 and the inductor L323_1 .
  • the capacitor C323_1 and the inductor L323_1 perform energy storage.
  • the inductor L323_1 and the capacitor C323_1 release the stored energy, and the current flows through the freewheeling diode D323_1 to the first output terminal Pi_322, so that the first output terminal Pi_322 and the second output terminal Pi_322
  • the terminal Pi_323 outputs the load power supply signal Vout.
  • a resistor R323_1 is also connected in series between the first output terminal Pi_322 and the second output terminal Pi_323, because the resistor R323_1 can be increased or increased depending on the actual application. Omitted (non-essential components), so it is represented by a dashed line in the figure.
  • the temperature sampling device 31 is shown in FIG. 16, and in order to limit the current and facilitate the adjustment of the output power level of the drive module to the load, the output terminal Pi_310 of the temperature sampling device 31 and the drive control circuit A resistor R31_1 is also coupled between the feedback pin CS of the 321, and a resistor R32_1 is coupled between the feedback pin CS of the drive control circuit 321 and the load feedback terminal Pi_320 (in order to describe only the driving module in Figures 17 to 19)
  • the circuit structure is no longer shown, but in actual connection, a resistor R31_1 is coupled between the output terminal Pi_310 of the temperature sampling device 31 and the feedback pin CS of the drive control circuit 321, and the feedback lead of the drive control circuit 321
  • a resistor R32_1 is coupled between the pin CS and the load feedback terminal Pi_320).
  • the working principle of the drive control circuit 321 is based on the comparison between the reference voltage set at the reference terminal of the internal operational amplifier of the drive control circuit 321 and the voltage signal obtained on the feedback pin CS, and adjust the on and off timing of the switch circuit 322 according to the comparison result , So as to finally make the voltage signal obtained on the feedback pin CS equal to the internally set reference voltage. Therefore, in the analysis, the voltage signal (Vcs) obtained on the feedback pin CS is stabilized at the reference voltage.
  • the resistance R31_1 and the resistance R32_1 are used as the fixed coefficients of the above analysis equation, which are related to the level of the drive module to adjust the output power to the load.
  • the resistance values of the resistance R31_1 and the resistance R32_1 are related to the performance of temperature protection.
  • the temperature sampling signal Vtem Take the temperature sampling signal Vtem as a fixed value corresponding to the temperature of the LED module sensed by the temperature sampling device as an example (for example, the LED module works at 80°C, and the temperature sampling signal Vtem corresponds to the value output by the 80°C temperature sampling device), The larger the value of R32_1/R31_1 is, the drive module will reduce the power output to the load to a smaller value.
  • the drive module When the value of R32_1/R31_1 is larger, the drive module will reduce the power output to the load to a higher value.
  • those skilled in the art can select the parameters of the resistor R31_1 and the resistor R32_1 according to the temperature protection performance desired to be achieved in the actual situation.
  • the working principle of the drive control circuit 321 is based on the comparison between the reference voltage Vref set by the reference terminal of the operational amplifier in the drive control circuit 321 and the voltage signal Vcs obtained on the feedback pin CS.
  • Vcs is greater than Vref
  • the drive The control circuit 321 reduces the duty cycle of the switch Q5 through the control signal output by the pin GT, so that the current flowing through the load is reduced, thereby reducing the load power
  • Vcs is less than Vref
  • the drive control circuit 321 outputs through the pin GT
  • the control signal increases the duty cycle of the switch Q5, so that the current flowing through the load increases, thereby increasing the load power.
  • the drive module can either work in a constant current mode, and adjust the output power by adjusting the output current, or work in a constant voltage module, and adjust the output power by adjusting the output voltage.
  • the driving module includes a driving control circuit 321, a switch circuit 322, and a power conversion circuit 323.
  • the power conversion circuit 323 has a first pin Pi_321, a first output terminal Pi_322, and a second output terminal Pi_323, and receives an external power supply signal Vin (direct current signal) through its first pin Pi_321 to perform energy conversion.
  • the output terminal Pi_322 and the second output terminal Pi_323 output a load power supply signal Vout.
  • the power conversion circuit 323 is coupled to the switch circuit 322.
  • the switch circuit 322 is controlled by the drive control circuit 321.
  • the power conversion circuit 323 includes an inductor L323_2, a freewheeling diode D323_2, and a capacitor C323_2.
  • One end of the inductor L323_2 is connected to the first pin Pi_321, and the other end is coupled to the first end of the switch circuit 322.
  • the capacitor C323_2 is coupled between the first output terminal Pi_322 and the second output terminal Pi_323 to stabilize the voltage difference between the first output terminal Pi_322 and the second output terminal Pi_323.
  • the cathode of the freewheeling diode D323_2 is coupled to the first output terminal Pi_322, the anode is coupled to the first end of the switch circuit 322.
  • the switch circuit 322 includes a switch Q6, which has a first terminal, a second terminal, and a control terminal, and uses the first terminal of the switch Q6 as the first terminal of the switch circuit 322 to be coupled to the inductor L323_2 of the power conversion circuit 323 At the other end, the second end of the switch Q6 is coupled to the second output terminal Pi_323, and is also connected to the power ground GND via a sampling resistor Rcs_2, and the control end of the switch Q6 is coupled to the output pin GT of the drive control circuit 321 .
  • the sampling resistor Rcs_2 arranged between the second end of the switch Q6 and the power ground GND is used to form a current detection circuit, which converts the current flowing through the switch Q6 into a voltage value to form the feedback signal Vfb.
  • the feedback signal Vfb on the current detection circuit can be collected and transmitted to the drive control circuit 321 via the load feedback terminal Pi_320.
  • the switch circuit 322 in the figure only shows the connection relationship, and the switch circuit 322 is not included in the power conversion circuit 323.
  • the drive control circuit 321 determines the on and off timing of the switch Q6 according to the temperature sampling signal Vtem and the feedback signal Vfb.
  • the drive control circuit 321 controls the switch Q6 to be turned on
  • the external power supply signal Vin flows in from the first pin Pi_321, and flows out to the power ground GND through the inductor L323_2, the switch Q6, and the sampling resistor Rcs_2.
  • the current flowing through the inductor L323_2 increases with time, the inductor L323_2 is in the energy storage state, and at the same time, the capacitor C323_2 is in the energy release state.
  • the inductor 2203b When the switch Q6 is turned off, the inductor 2203b is in a discharged state, and the current of the inductor L323_2 decreases with time.
  • the current of the inductor L323_2 flows freely to the capacitor C323_2 and the first output terminal Pi_322 through the freewheeling diode D323_2. Therefore, the load power supply signal Vout is output at the first output terminal Pi_322 and the second output terminal Pi_323. It should be noted that in order to prevent the load from working at no load, the output voltage is stabilized.
  • a resistor R323_2 is also connected in series between the first output terminal Pi_322 and the second output terminal Pi_323. Since the resistor R323_2 can be added or omitted (non-essential component) depending on the actual application, it is represented by a dashed line in the figure It.
  • the driving module includes a driving control circuit 321, a switch circuit 322, and a power conversion circuit 323 .
  • the power conversion circuit 323 has a first pin Pi_321, a first output terminal Pi_322, and a second output terminal Pi_323, and receives an external power supply signal Vin (direct current signal) through its first pin Pi_321 to perform energy conversion.
  • the output terminal Pi_322 and the second output terminal Pi_323 output a load power supply signal Vout.
  • the power conversion circuit 323 is coupled to the switch circuit 322.
  • the switch circuit 322 is controlled by the drive control circuit 321.
  • the power conversion circuit 323 includes an inductor L323_3, a freewheeling diode D323_3, and a capacitor C323_3.
  • One end of the inductor L323_3 is connected to the first output terminal Pi_322, and the other end is coupled to the second end of the switch circuit 322.
  • the capacitor C323_3 is coupled between the first output terminal Pi_322 and the second output terminal Pi_323 to stabilize the voltage difference between the first output terminal Pi_322 and the second output terminal Pi_323.
  • the anode of the freewheeling diode D323_3 is coupled to the first output terminal Pi_322 is connected in parallel to the power ground GND, and the cathode is coupled to the second end of the switch circuit 322.
  • the switch circuit 322 includes a switch Q7, which has a first terminal, a second terminal, and a control terminal.
  • the first terminal of the switch Q7 is used as the first terminal of the switch circuit 322 to be coupled to the first pin Pi_321, and
  • the first terminal of the switch Q7 is also coupled to the feedback pin CS of the drive control circuit 321 via the load feedback terminal Pi_320, so that the current flowing through the switch Q7 is fed back to the drive control circuit 321 in the form of a feedback signal Vfb, and the switch Q7 is switched
  • the second end of the switch circuit 322 is used as the second end of the switch circuit 322 to be coupled to the power conversion circuit 323, and the control end of the switch Q7 is coupled to the output pin GT of the drive control circuit 321.
  • the drive control circuit 321 determines the on and off timing of the switch Q7 according to the temperature sampling signal Vtem and the feedback signal Vfb.
  • the switch Q7 When the switch Q7 is turned on, the external power supply signal Vin flows in from the first terminal of the switch Q7, flows into the second output terminal Pi_323 through the switch Q7, the inductor L323_3, the capacitor C323_3 and the first output terminal Pi_322.
  • the current flowing through the inductor L323_3 and the voltage of the capacitor C323_3 increase with time, and the inductor L323_3 and the capacitor C323_3 are in an energy storage state.
  • the inductor L323_3 When the switch Q7 is turned off, the inductor L323_3 is in a discharged state, and the current of the inductor L323_3 decreases with time. At this time, the current of the inductor L323_3 returns to the inductor L323_3 through the first output terminal Pi_322, the second output terminal Pi_323, and the freewheeling diode D323_3 to form a freewheeling current. Therefore, the load power supply signal Vout is output at the first output terminal Pi_322 and the second output terminal Pi_323.
  • a resistor R323_3 is also connected in series between the first output terminal Pi_322 and the second output terminal Pi_323, because the resistor R323_3 can be increased or increased depending on the actual application. Omitted (non-essential components), so it is represented by a dashed line in the figure.
  • the driving module includes a driving control circuit 321, a switch circuit 322, and a power conversion circuit 323.
  • the power conversion circuit 323 has a first pin Pi_321, a first output terminal Pi_322, and a second output terminal Pi_323, and receives an external power supply signal Vin (direct current signal) through its first pin Pi_321 to perform energy conversion.
  • the output terminal Pi_322 and the second output terminal Pi_323 output a load power supply signal Vout.
  • the power conversion circuit 323 is coupled to the switch circuit 322.
  • the switch circuit 322 is controlled by the drive control circuit 321.
  • the power conversion circuit 323 includes an inductor L323_4, a freewheeling diode D323_4, and a capacitor C323_4.
  • One end of the inductor L323_4 is connected to the first pin Pi_321, and the other end is coupled to the first end of the switch circuit 322.
  • the capacitor C323_4 is coupled between the first output terminal Pi_322 and the second output terminal Pi_323 to stabilize the voltage difference between the first output terminal Pi_322 and the second output terminal Pi_323.
  • the cathode of the freewheeling diode 2242_2 is coupled to the second output terminal Pi_323, the anode is coupled to the first end of the switch circuit 322.
  • the switch circuit 322 includes a switch Q8, which has a first terminal, a second terminal, and a control terminal.
  • the first terminal of the switch Q8 is used as the first terminal of the switch circuit 322.
  • the first terminal of the switch circuit 322 is coupled to the power conversion circuit 323.
  • the second end of the switch Q8 is connected to the power ground GND via a sampling resistor Rcs_3, and the control end of the switch Q8 is coupled to the output pin GT of the driving control circuit 321.
  • the sampling resistor Rcs_3 arranged between the second end of the switch Q8 and the power ground GND is used to form a current detection circuit, which converts the current flowing through the switch Q8 into a voltage value to form the feedback signal Vfb.
  • the drive control circuit 321 determines the on and off timing of the switch Q8 according to the temperature sampling signal Vtem and the feedback signal Vfb.
  • the switch Q8 When the switch Q8 is turned on, the external power supply signal Vin flows in from the first pin Pi_321, flows through the inductor L323_4, the switch Q8, and the sampling resistor Rcs_3, and then flows into the second pin 221.
  • the current flowing through the inductor L323_4 increases with time, and the inductor L323_4 is in the energy storage state; the voltage of the capacitor C323_4 decreases with time, and the capacitor C323_4 is in the discharge state to maintain the gap between the first output terminal Pi_322 and the second output terminal Pi_323 The voltage.
  • the inductor L323_4 When the power switch Q8 is turned off, the inductor L323_4 is in a discharged state, and the current of the inductor L323_4 decreases with time. At this time, the current of the inductor L323_4 returns to the inductor L323_4 through the freewheeling diode D323_4, the second output terminal Pi_323, and the first output terminal Pi_322 to form a freewheeling current. At this time, the capacitor C323_4 is in an energy storage state, and the voltage of the capacitor C323_4 increases with time. Therefore, the load power supply signal Vout is output at the first output terminal Pi_322 and the second output terminal Pi_323.
  • a resistor R323_4 is also connected in series between the first output terminal Pi_322 and the second output terminal Pi_323, because the resistor R323_4 can be increased or increased depending on the actual application. Omitted (non-essential components), so it is represented by a dashed line in the figure.
  • the power conversion circuit mentioned in at least one of the above examples may further include a clamping component, which may be connected to the current detection circuit for the current flowing through the current detection circuit or the voltage difference between the two ends of the current detection circuit exceeds a preset value At this time, a clamp operation is performed on the loop of the current detection circuit to limit the current flowing through the current detection circuit.
  • the clamping component may be, for example, a plurality of diodes, the plurality of diodes are connected in series to form a diode string, and the diode string and the current detection circuit are connected in parallel with each other.
  • the diode string connected in parallel to the current detection circuit will quickly turn on, so that both ends of the current detection circuit can be limited to a specific level. For example, if the diode string is composed of 5 diodes, since the turn-on voltage of a single diode is about 0.7V, the diode string can clamp the cross voltage of the current detection circuit to about 3.5V.
  • the temperature protection unit 32 corresponding to any one of the embodiments described in FIGS. 13 to 19 is only an example, and is not a limitation on the temperature protection unit 32.
  • the temperature protection unit 32 includes a heat dissipation module, which is disposed at the circuit to be protected and is coupled to the temperature sampling device 31, so that the heat dissipation module performs a heat dissipation operation according to the received temperature sampling signal Vtem.
  • the heat dissipation module may, for example, include a fan, and the heat dissipation module controls the fan to rotate at a fixed rotation speed or a rotation speed corresponding to the size of the temperature sampling signal Vtem according to the temperature sampling signal Vtem, so as to dissipate heat from the circuit to be protected.
  • the temperature protection device 30 may be provided in an LED lighting system, that is, the circuit to be protected is an LED module, and the lighting system may include a high-power lighting system (for example, the output power to the LED module exceeds 30W), Lighting system with dimming function, etc.
  • the temperature protection unit 32 can be the temperature protection unit 32 in any of the embodiments in FIGS. 14-19; when the lighting system is a lighting system with dimming function,
  • the temperature protection unit 32 may include a dimming module coupled to the temperature sampling device 31 and configured to output a dimming signal for reducing the brightness of the LED load circuit in the LED lighting system according to the temperature sampling signal Vtem.
  • the temperature protection device proposed in the above embodiments senses the ambient temperature of the circuit to be protected through a thermistor, which is low in cost, and achieves the effect of cooling the circuit to be protected by reducing the output power, which is energy-saving and safe; in addition, the temperature protection device
  • the temperature sampling device in can be directly coupled to the pins of the drive control circuit in the temperature protection unit, neither need to modify the circuit of the temperature protection unit itself, nor need to design additional circuits that are compatible. Realize temperature protection function, strong versatility.
  • this application also proposes an LED lighting system.
  • FIG. 20 shows a circuit block diagram of an embodiment of the LED lighting system of this application.
  • the LED lighting system includes The temperature sampling device 20, the switching power supply 40, and the LED load circuit 10 described in any one of the previous embodiments of FIGS. 1 to 12C.
  • the switching power supply 40 is coupled to the LED load circuit 10 for supplying external AC power.
  • the AC signal AC is converted into the power supply signal of the LED load circuit 10.
  • the switching power supply 40 is also coupled to the temperature sampling device 20, so that the switching power supply 40 can reduce the output to the LED load circuit according to the temperature sampling signal Vtem provided by the temperature sampling device 20 Power operation.
  • the lighting system may include a high-power lighting system (for example, the output power to the LED module exceeds 30W), a lighting system with a dimming function, etc., which is not limited in this application.
  • the switching power supply 40 may be called a power module
  • the LED load circuit 10 may be called an LED module
  • the temperature sampling device 20 may be called a temperature protection circuit
  • the temperature sampling signal Vtem may be called a temperature protection signal Vtem.
  • the LED lighting system includes a temperature protection circuit 20, a power supply module 40, and an LED module 10.
  • the power module 40 is electrically connected to an external power source for receiving an external power signal AC and generating a driving signal.
  • the LED module 10 is electrically connected to the power module 40 for receiving the driving signal to light up.
  • the temperature protection circuit 20 is electrically connected to the power module 40 to collect the operating temperature of the power module 120 or the LED module 10 and generate a temperature protection signal Vtem according to the collected temperature.
  • the power module 40 receives the temperature protection signal Vtem and adjusts the output power according to the temperature protection signal Vtem. When the operating temperature is higher than the set threshold, the power module 40 reduces the output power to reduce heat generation.
  • the operating temperature of the LED lamp can be controlled within the rated temperature, which ensures the normal operation of the LED lamp and prolongs the service life of the LED lamp.
  • the switching power supply 40 includes a rectifier module 41, a filter module 42, and a driving module 43.
  • the rectification module 41 receives the AC signal AC output by the external AC power supply through its first rectification input terminal Pi_411 and second rectification input terminal Pi_412, and rectifies the AC signal AC, and then the first rectification output terminal Pi_413 and The second rectified output terminal Pi_414 outputs the rectified signal.
  • the filter module 42 is coupled to the rectifier module 41, and is configured to receive and filter the rectified signals output from the first rectified output terminal Pi_413 and the second rectified output terminal Pi_414.
  • the second filter output terminal Pi_422 outputs the power supply signal Vdc.
  • the driving module 43 is coupled to the filter module 42 for energy conversion of the filtered rectified signal to supply power to the LED load, and the driving module 43 is also coupled to the temperature sampling device 20 to perform reduction to the LED according to the temperature sampling signal Vtem Operation of the output power of the load circuit.
  • the second rectified input terminal Pi_412, the second rectified output terminal Pi_414, and the second filtered output terminal Pi_422 are used as reference low potential terminals and are connected to the power ground GND or the reference ground SGND.
  • FIG. 22 shows a schematic diagram of the circuit structure of the rectifier module in an embodiment of the LED lighting system of this application.
  • the rectifier module 41 is a bridge rectifier circuit and the rectifier module 24 has a first rectifier The input terminal Pi_411, the second rectification input terminal Pi_412, the first rectification output terminal Pi_413, and the second rectification output terminal Pi_414.
  • the rectifier module 24 further includes a first rectifier diode D41_1, a second rectifier diode D41_2, a third rectifier diode D41_3, and a second rectifier diode D41_1.
  • the four rectifier diodes D41_4 are used for full-wave rectification of the received AC signal AC.
  • the anode of the first rectifier diode D41_1 is coupled to the second rectification output terminal Pi_414, and the cathode of the first rectifier diode D41_1 is coupled to the second rectification input terminal Pi_412.
  • the anode of the second rectifier diode D41_2 is coupled to the second rectification output terminal Pi_414, and the cathode of the second rectifier diode D41_2 is coupled to the first rectification input terminal Pi_411.
  • the anode of the third rectifier diode D41_3 is coupled to the second rectification input terminal Pi_412, and the cathode of the third rectifier diode D41_3 is coupled to the first rectification output terminal Pi_413.
  • the anode of the fourth rectifier diode D41_4 is coupled to the first rectification input terminal Pi_411, and the cathode of the fourth rectifier diode D41_4 is coupled to the first rectification output terminal Pi_413.
  • the operation of the rectification module 41 is described as follows.
  • the AC signal AC is in a positive half wave, it flows in through the first rectification input terminal Pi_411, the fourth rectifier diode D41_4 and the first rectification output terminal Pi_413 in sequence, and then flows through the second rectification output terminal Pi_414 and the first rectification output terminal Pi_414 in sequence.
  • the diode D41_1 and the second rectification input terminal Pi_412 then flow out.
  • the AC signal flows in through the second rectification input terminal Pi_412, the third rectifier diode D41_3, and the first rectification output terminal Pi_413 in sequence, and then flows through the second rectification output terminal Pi_414 and the second rectification output terminal Pi_414 in sequence.
  • the rectifier diode D41_2 and the first rectifier input terminal Pi_411 flow out. Therefore, regardless of whether the AC signal AC is in a positive half-wave or a negative half-wave, the positive pole of the rectified signal of the rectifier module 41 is located at the first rectified output terminal Pi_413, and the negative pole is located at the second rectified output terminal Pi_414. According to the above operation description, the rectified signal output by the rectifying module 41 is a full-wave rectified signal.
  • the structure of the rectifier module 41 is not limited to this, and the rectifier module 41 may also be other types of full-wave rectifier circuits or half-wave rectifier circuits, without affecting the functions to be achieved by the solution of the present application.
  • FIG. 23 shows a schematic diagram of the circuit structure of the filter module in an embodiment of the LED lighting system of this application.
  • the filter module 42 includes a capacitor C42_1, and one end of the capacitor C42_1 is coupled to the first rectified output The terminal Pi_413 and the first filtered output terminal Pi_421, and the other end is coupled to the second rectified output terminal Pi_414 and the second filtered output terminal Pi_422, so as to perform processing on the rectified signal output from the first rectified output terminal Pi_413 and the second rectified output terminal Pi_414
  • Low-pass filtering is used to filter high frequency components in the rectified signal to form a filtered signal, which is output by the first filtered output terminal Pi_421 and the second filtered output terminal Pi_422 as the power supply signal Vdc.
  • FIG. 24 shows a schematic diagram of the circuit structure of the filter module in another embodiment of the LED lighting system of this application.
  • the filter module 42 includes a ⁇ -type filter circuit
  • the ⁇ -type filter circuit includes A capacitor C42_2, an inductor L42_1, and a capacitor C42_3.
  • a ⁇ -type filter circuit looks like the symbol " ⁇ " in shape or structure.
  • One end of the capacitor C42_2 is connected to the first rectified output terminal Pi_413 and coupled to the first filter output terminal Pi_421 via the inductor L42_1, and the other end of the capacitor C42_2 is connected to the second rectified output terminal Pi_414 and the second filter output terminal Pi_422.
  • the inductor L42_1 is coupled between the first rectified output terminal Pi_413 and the first filtered output terminal Pi_421.
  • One end of the capacitor C42_3 is connected to the first filter output terminal Pi_421 and coupled to the first rectified output terminal Pi_413 via the inductor L42_1, and the other end is connected to the second rectified output terminal Pi_414 and the second filter output terminal Pi_422.
  • the inductance value of the inductor L42_1 in the embodiment shown in FIG. 24 is preferably selected from the range of 10 nH-10 mH.
  • the capacitance of the capacitor C42_1 in FIG. 23 and the capacitors C42_2 and C42_3 in FIG. 24 are preferably selected from the range of 100 pF to 1 uF.
  • the structure of the filter module 42 is not limited to this.
  • the filter module 42 can also be other types such as LC filter circuit, RC filter circuit, LC ⁇ filter circuit, RC ⁇ filter circuit, etc., without affecting the plan of the application. Achieved features.
  • the driving module 43 may use the driving device described in any one of the embodiments in FIGS. 14 to 19, wherein the external power supply signal Vin received by the driving device in FIGS. 14 to 19 is filtered.
  • the power supply signal Vdc output by the module 42 and the load power supply signal Vout output by the module 42 are used as the power supply signal of the LED load circuit.
  • FIGS. 14 to 19 For the circuit structure and working principle, please refer to the description of FIGS. 14 to 19, which will not be repeated here.
  • FIG. 25 shows a schematic structural diagram of an LED load circuit in an embodiment of the LED lighting system of this application.
  • the positive terminal of the LED load circuit 10 is coupled to the first output terminal Pi_322 of the driving module.
  • the negative terminal is coupled to the second output terminal Pi_323 of the driving module.
  • the LED load circuit 10 includes at least one LED unit 100a, and when there are more than two LED units 100a, they are connected in parallel.
  • the positive terminal of each LED unit is coupled to the positive terminal of the LED load circuit 10 to be coupled to the first output terminal Pi_322; the negative terminal of each LED unit is coupled to the negative terminal of the LED load circuit 10 to be coupled to the second output terminal Pi_323.
  • the LED unit 100a includes at least one LED assembly 1000a, that is, the light source of the LED lamp.
  • the LED components 1000a are connected in series to form a string, the positive terminal of the first LED component 1000a is coupled to the positive terminal of the corresponding LED unit 100a, and the negative terminal of the first LED component 1000a is coupled to the next (first Two) LED assembly 1000a.
  • the positive terminal of the last LED component 1000a is coupled to the negative terminal of the previous LED component 1000a, and the negative terminal of the last LED component 1000a is coupled to the negative terminal of the corresponding LED unit 100a.
  • FIG. 26 shows a schematic structural diagram of an LED load circuit in another embodiment of the LED lighting system of this application.
  • the positive terminal of the LED load circuit 10 is coupled to the first output terminal Pi_322 of the driving module, and the negative terminal is The terminal is coupled to the second output terminal Pi_323 of the driving module.
  • the LED load circuit 10 of this embodiment includes at least two LED units 100b, and the positive terminal of each LED unit 100b is coupled to the positive terminal of the LED load circuit 10, and the negative terminal is coupled to the negative terminal of the LED load circuit 10.
  • the LED unit 100b includes at least two LED components 1000b. The connection of the LED components 1000b in the LED unit 100b is as described in FIG. 25.
  • the negative electrode of the LED component 1000b is coupled to the positive electrode of the next LED component 1000b, and the second LED component 1000b is The positive pole of one LED assembly 1000b is coupled to the positive pole of the associated LED unit 100b, and the negative pole of the last LED assembly 1000b is coupled to the negative pole of the associated LED unit 100b. Furthermore, the LED units 100b in this embodiment are also connected to each other. The positive electrodes of the n-th LED assembly 1000b of each LED unit 100b are connected to each other, and the negative electrodes are also connected to each other. Therefore, the connection between the LED components of the LED load circuit 10 of this embodiment is a mesh connection. In practical applications, the number of LED components 1000b included in the LED unit 100b is preferably 15-25, and more preferably 18-22.
  • the LED lighting system further includes a start-up protection circuit 44.
  • FIG. 27 shows a schematic diagram of the circuit block diagram of the startup protection circuit in an embodiment of the LED lighting system of this application.
  • the startup protection circuit 44 is coupled to the temperature detection unit 21 of the temperature sampling device 20 Between the detection terminal Pi_210 and the reference terminal Pi_222 that provides the first reference signal, the temperature sampling signal Vtem is used to start protection for the LED load circuit when the LED lighting system is powered on.
  • FIG. 28 shows a schematic diagram of the circuit structure of the start-up protection circuit in an embodiment of the LED lighting system of this application.
  • the temperature detection unit 21 shown in FIG. 2 is shown in the figure.
  • the thermistor R21_2 is NTC as an example.
  • the startup protection circuit 44 includes a capacitor C44_1. One end of the capacitor C44_1 is coupled to the detection terminal Pi_210 of the temperature detection unit 21, and the other end is coupled to the reference terminal Pi_222 (FIG. 28 It is shown that the reference terminal Pi_222 is connected to the power ground GND).
  • the power supply Vcc charges the capacitor C44_1 during the initial power-on phase, and the voltage on the capacitor C44_1 slowly rises from zero, that is, the detection signal Vdec is starting The stage is very small. At this time, it can be seen that the resistance value of the thermistor R21_2 is small. According to the working principle of the signal processing unit 22 described above with respect to FIG. 5, it can be seen that the smaller the resistance value of the thermistor R21_2, the signal processing The larger the temperature sampling signal Vtem output by the unit 22 is.
  • the temperature sampling signal Vtem is very large, so that the output power of the driving module to the LED load circuit is very small.
  • the LED module of the LED load circuit is very dark.
  • the temperature sampling The signal Vtem slowly decreases, and the driving module slowly increases the power output to the LED load circuit according to the temperature sampling signal Vtem, so that the LED module of the LED load circuit slowly changes from dark to bright, and the LED load circuit completes its soft-start process.
  • the LED lighting system proposed in the above embodiments perceives the ambient temperature of the LED load circuit through thermistor, and achieves the effect of cooling the LED load circuit by reducing the output power, which is low in cost, energy-saving and safe; in addition, a temperature sampling device It can be directly coupled with the pins of the switching power supply in the existing LED lighting system, neither need to modify the circuit of the switching power supply itself in the LED lighting system, nor need to design additional circuits or chips that are compatible The temperature protection function can be realized, and the versatility is strong.
  • the present application also proposes a temperature collection method, which is applied to a temperature sampling device, wherein the temperature sampling device includes a circuit that changes the resistance value as the ambient temperature changes.
  • the temperature collection method includes step S20 and step S21.
  • step S20 the detection signal in the temperature sampling device affected by the change of the resistance value is restricted.
  • the temperature sampling device includes a temperature detection unit and a signal processing unit, wherein the resistance of the temperature detection unit will be changed by the environmental change of the circuit to be protected, and the detection signal is the output of the temperature detection unit affected by the change of its resistance.
  • the electrical signal, the circuit structure of the temperature detection unit, and the detection signal are affected by changes in the resistance value.
  • the signal processing unit includes an amplification module and a feedback module, and the feedback module limits the detection signal in the temperature sampling device that is affected by the blocking change.
  • the feedback module limits the detection signal in the temperature sampling device that is affected by the blocking change.
  • FIG. 4 to FIG. 7 each of the embodiments describes the detailed process of the feedback module 221 limiting the detection signal Vdec, which will not be repeated here.
  • the feedback module 221 forms a feedback signal FB based on the temperature sampling signal Vtem output by the signal processing unit 22 to limit the change of the detection signal Vdec.
  • step 21 a temperature sampling signal corresponding to the change in the resistance value is output; wherein the temperature sampling signal is formed when the detection signal is subject to the restriction.
  • the signal processing unit includes an amplifying module and a feedback module, and the amplifying module outputs a temperature sampling signal corresponding to the blocking change.
  • the amplifying module 222 amplifies the signal received by its input terminal Pi_221 based on the limited detection signal Vdec, so as to output a temperature sampling signal Vtem corresponding to the resistance change of the temperature detection unit 21.
  • this application also proposes a temperature protection method for LED lamps, and the temperature protection method is applied to a temperature protection device.
  • FIG. 30 shows a flowchart of an embodiment of the temperature protection method of the LED lamp of this application.
  • the temperature protection method of the LED lamp includes step S30, step S31, and step S32.
  • step S30 the detection signal in the temperature sampling device affected by the change of the resistance value is restricted.
  • the temperature protection device includes a temperature sampling device and a temperature protection unit.
  • the temperature sampling device includes a temperature detection unit and a signal processing unit.
  • the resistance of the temperature detection unit will be changed by the environment of the circuit to be protected.
  • the detection signal is generated by the temperature detection unit.
  • the output of the electrical signal is affected by the change of its resistance, and the circuit structure of the temperature detection unit and the detection signal are affected by the change of its resistance.
  • the signal processing unit includes an amplification module and a feedback module, and the feedback module limits the detection signal in the temperature sampling device that is affected by the blocking change.
  • the feedback module limits the detection signal in the temperature sampling device that is affected by the blocking change.
  • each of the embodiments describes the detailed process of the feedback module 221 limiting the detection signal Vdec, which will not be repeated here.
  • the feedback module 221 forms a feedback signal FB based on the temperature sampling signal Vtem output by the signal processing unit 22 to limit the change of the detection signal Vdec.
  • step 31 a temperature sampling signal corresponding to the change in the resistance value is output; wherein the temperature sampling signal is formed when the detection signal is subject to the restriction.
  • the signal processing unit includes an amplifying module and a feedback module, and the amplifying module outputs a temperature sampling signal corresponding to the blocking change.
  • the amplifying module 222 amplifies the signal received by its input terminal Pi_221 based on the limited detection signal Vdec, so as to output a temperature sampling signal Vtem corresponding to the resistance change of the temperature detection unit 21.
  • step S32 the temperature protection operation of the LED lamp is performed based on the temperature sampling signal.
  • the temperature protection unit is coupled to the temperature sampling device to receive the temperature sampling signal output by the temperature sampling device, and performs a temperature protection operation on the LED lamp based on the temperature sampling signal.
  • the temperature protection unit includes a switching power supply in an LED lamp, and the switching power supply reduces the output power supply based on the temperature sampling signal.
  • the switching power supply reduces the output power supply based on the temperature sampling signal.
  • the driving module in the switching power supply 40 is used to reduce the output power based on the temperature sampling signal Vtem, and the driving control circuit 321 in the driving module determines the switching circuit according to the temperature sampling signal Vtem and the feedback signal Vfb
  • the drive control circuit 321 controls the turn-on and turn-off timing of the switch circuit 322 to achieve the purpose of reducing the load current Ics, thereby reducing the on and off of the switch in 322. This is the power output to the load, that is, the power supplied by the switching power supply 40.
  • the LED lamp is an LED lamp with a dimming function
  • the temperature protection unit includes a dimming module in the LED lamp, and the dimming module adjusts the output dimming signal based on the temperature sampling signal to ensure that the temperature Decrease the brightness of the LED light when increasing.
  • the temperature protection unit includes a heat dissipation device, which is disposed at the circuit to be protected and is coupled to the temperature sampling device, so that the heat dissipation device performs a heat dissipation operation according to the received temperature sampling signal.
  • the heat dissipation device may include, for example, a fan, and the heat dissipation device controls the fan to rotate at a fixed rotation speed or a rotation speed corresponding to the size of the temperature sampling signal according to the temperature sampling signal, so as to dissipate heat from the circuit to be protected.
  • the temperature sampling device, temperature protection device and method, and lighting system proposed in this application sense the ambient temperature of the LED load circuit through a thermistor, and achieve the effect of cooling the LED load circuit by reducing the output power, with low cost and energy saving And it is safe; in addition, the temperature sampling device can be directly coupled with the pins of the switching power supply in the existing LED lighting system, neither need to modify the circuit of the switching power supply in the LED lighting system, nor need additional design
  • the matched circuit or chip can realize the temperature protection function, which has strong versatility.

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Abstract

本申请公开一种温度采样装置、温度保护装置及方法、以及照明系统，包括：温度检测单元和信号处理单元，所述温度检测单元具有检测端，用于受待保护电路的环境温度变化的影响而改变自身的阻值；所述信号处理单元耦接于所述检测端，用于限制所述温度检测单元中受所述阻值变化影响的检测信号，以输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的。所述温度采样装置、温度保护装置及方法、以及照明系统结构简单，成本低廉，并且温度采样装置可以直接与现有的LED照明系统中的开关电源本身具有的引脚相耦接，通用性强。

Description

温度采样装置、温度保护装置及方法、以及照明系统 技术领域
本申请涉及温度保护装置技术领域，尤其涉及一种温度采样装置、温度保护装置及方法、以及照明系统。
背景技术
随着电力电子技术的快速发展以及人们对生活要求的提升，各种应用于不同环境场合的电力器件以及极限设计的供电方案也越来越多的涌现。伴随而来的是电力电子器件在大功率工作情况下的温度过高而导致的寿命降低，或者由于温度过高而使得电力电子器件中的热感元器件失效导致的电力电子器件异常作业。
以应用于照明领域的电力电子器件为例。如，应用于户外照明的LED灯长期以高功率工作，在使用中LED灯的温度会持续升高，当温度过高时，如果不采用额外的手段对LED灯降温，LED灯则很容易烧坏，寿命很短；又如，若室内照明用LED灯的散热空间不足，很容易造成因LED灯温度过高而使得LED灯珠或LED电源因过热而损坏，这影响了LED驱动器的寿命。
虽然有些灯具可以通过重新更换具有温度保护功能的IC芯片来实现温度检测，但是这种方式使得灯具已有的驱动器不能使用，并且在针对不同的场合需要而设计的不同的驱动器具有兼容性差且成本高等问题。
发明内容
鉴于以上所述相关技术的缺点，本申请的目的在于提供一种温度采样装置、温度保护装置及方法、以及照明系统。
为实现上述目的及其他相关目的，本申请第一方面公开一种温度采样装置，包括：温度检测单元和信号处理单元，所述温度检测单元具有检测端，用于受待保护电路的环境温度变化而改变自身的阻值；所述信号处理单元耦接于所述检测端，用于限制所述温度检测单元中受所述阻值变化影响的检测信号，以输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的；其中，所述温度采样信号用于向温度保护装置传输。
在本申请第一方面的某些实施例中，所述阻值的变化与环境温度的变化之间具有单调性。
在本申请第一方面的某些实施例中，所述温度采样信号在环境温度达到起始保护温度时予以输出。
在本申请第一方面的某些实施例中，所述温度采样信号的变化与阻值的变化之间具有单调性。
在本申请第一方面的某些实施例中，所述信号处理单元基于所述检测信号的变化而从第一状态转入第二状态；其中，在第二状态期间，所述信号处理单元产生所述温度采样信号。
在本申请第一方面的某些实施例中，所述温度检测单元包括：串联的热敏电阻及分压电阻，所述检测端位于热敏电阻及分压电阻之间。
在本申请第一方面的某些实施例中，所述热敏电阻包括随环境温度变化而阻值正向变化的可变电阻。
在本申请第一方面的某些实施例中，所述热敏电阻包括随环境温度变化而阻值负向变化的可变电阻。
在本申请第一方面的某些实施例中，所述信号处理单元包括：放大模块，其输入端耦接所述检测端，其参考端接入第一参考信号，以及其输出端输出所述温度采样信号；以及反馈模块，耦接于所述检测端和所述放大模块的输出端之间，用于将根据所述温度采样信号而形成的反馈信号反馈至所述检测端，以限制所述检测信号的变化；其中，所述放大模块基于经限制的检测信号，对所述输入端所接收的信号进行放大处理输出所述温度采样信号。
在本申请第一方面的某些实施例中，所述反馈模块用于确定所述温度检测单元的阻值变化范围对应于预设的所述温度采样信号的信号量变化范围。
在本申请第一方面的某些实施例中，所述放大模块包括接入所述放大模块的参考端和输出端之间电路的三极管，其控制端耦接所述放大模块的输入端。
在本申请第一方面的某些实施例中，所述放大模块包括至少两个级联的三极管，第一级三极管的控制端耦接所述检测端，最后一级三极管接入所述放大模块的参考端与输出端之间电路中。
在本申请第一方面的某些实施例中，所述放大模块包括运算放大器，其两个输入端分别耦接所述放大模块的输入端和参考端，以及所述运算放大器的输出端耦接所述放大模块的输出端。
在本申请第一方面的某些实施例中，所述温度采样装置还包括输出单元，耦接所述信号处理单元的输出端，以输出所述温度采样信号。
在本申请第一方面的某些实施例中，所述输出单元包括：电压跟随模块，其输入端耦接 所述信号处理单元的输出端，参考端接收第二参考信号，以及所述电压跟随模块的输出端输出所述温度采样信号。
在本申请第一方面的某些实施例中，所述电压跟随模块包括：连接在所述电压跟随模块的输入端和参考端之间的三极管，所述三极管还连接所述电压跟随模块的输出端以输出所述温度采样信号。
在本申请第一方面的某些实施例中，所述温度采样装置还包括滤波单元，耦接所述信号处理单元的输出端，用于进行信号滤波。
在本申请第一方面的某些实施例中，所述待保护电路包括以下至少一种：开关电源、受热而降低/失去效能的电子部件、或LED负载电路。
本申请第二方面公开一种温度保护装置，包括：如第一方面任一实施例公开的温度采样装置和温度保护单元，所述温度采样装置用于检测待保护电路的环境温度并输出温度采样信号，所述温度保护单元耦接于所述温度采样装置以获得所述温度采样信号，为待保护电路提供与所述环境温度变化相应的温度保护操作。
在本申请第二方面的某些实施例中，所述待保护电路包括：开关电源、受热而降低/失去效能的电子部件、或LED负载电路。
在本申请第二方面的某些实施例中，所述温度保护单元包括负载的驱动模块，耦接于所述温度采样装置；所述温度保护操作包括：根据所述温度采样信号执行降低向负载输出功率的操作。
在本申请第二方面的某些实施例中，所述驱动模块包括：带有反馈引脚的驱动控制电路，所述温度采样信号传输至所述反馈引脚。
在本申请第二方面的某些实施例中，所述驱动模块包括：基于BUCK电路架构而构建的电路结构、基于BOOST电路架构而构建的电路结构、及基于BOOST-BUCK电路架构而构建的电路结构中的任一种。
在本申请第二方面的某些实施例中，所述温度采样信号区别于所述驱动模块获取的反映负载供电的反馈信号。
在本申请第二方面的某些实施例中，所述驱动模块还包括开关电路，所述驱动控制电路向开关电路输出的控制信号随所述温度采样信号的变化而变化。
在本申请第二方面的某些实施例中，所述温度保护单元包括散热模块，其设置在所述待保护电路处，耦接于所述温度采样装置；所述散热模块根据所述温度采样信号执行散热操作。
在本申请第二方面的某些实施例中，所述温度保护装置设置于一LED照明系统中。
在本申请第二方面的某些实施例中，所述温度保护单元包括调光模块，耦接于所述温度采样装置；所述调光模块，用于根据所述温度采样信号输出用于降低所述LED照明系统中LED负载电路的亮度的调光信号。
在本申请第二方面的某些实施例中，所述LED照明系统包括：输出功率高于30W的照明系统。
本申请第三方面公开一种LED照明系统，包括：如第一方面任一实施例公开的温度采样装置、LED负载电路、以及开关电源，所述LED负载电路受直流供电驱动，所述开关电源耦接于所述LED负载电路，用于将外部交流电源所提供的交流信号转换成所述LED负载电路的供电信号，并且，所述开关电源还耦接于所述温度采样装置，根据所述温度采样装置所提供的温度采样信号执行降低向LED负载电路输出功率的操作。
在本申请第三方面的某些实施例中，所述开关电源包括：整流模块，用于将所述交流信号进行整流处理并输出整流信号；滤波模块，耦接于所述整流模块，用于将所述整流信号进行滤波后输出；驱动模块，耦接于所述滤波模块，用于将滤波后的整流信号进行能量转换以向所述LED负载供电；其中，所述驱动模块还耦接于所述温度采样装置，根据所述温度采样信号执行降低向LED负载电路输出功率的操作。
在本申请第三方面的某些实施例中，所述驱动模块包括：带有反馈引脚的驱动控制电路，所述温度采样信号输至所述反馈引脚。
在本申请第三方面的某些实施例中，所述驱动模块包括：基于BUCK电路架构而构建的电路结构、基于BOOST电路架构而构建的电路结构、及基于BOOST-BUCK电路架构而构建的电路结构中的任一种。
在本申请第三方面的某些实施例中，所述温度采样信号区别于所述驱动模块获取的反映所述LED负载电路供电的反馈信号。
在本申请第三方面的某些实施例中，所述驱动模块还包括开关电路，所述驱动控制电路向开关电路输出的控制信号随所述温度采样信号的变化而变化。
在本申请第三方面的某些实施例中，所述LED照明系统还包括启动保护电路，耦接于所述温度采样装置中温度检测单元的检测端与提供第一参考信号的参考端之间，用于在LED照明系统上电启动时，根据所述温度采样信号对所述LED负载电路进行启动保护。
在本申请第三方面的某些实施例中，所述LED照明系统包括：输出功率高于30W的照明系统。
本申请第四方面公开一种温度采集的方法，应用于应用于温度采样装置，其中，所述温 度采样装置中包含随环境温度变化而改变阻值的电路，所述温度采集的方法包括：限制所述温度采样装置中受所述阻值变化影响的检测信号；输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的。
本申请第五方面公开一种温度保护方法，包括以下步骤：限制所述温度采样装置中受所述阻值变化影响的检测信号；输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的；基于所述温度采样信号执行对LED灯的温度保护操作。
在本申请第五方面的某些实施例中，所述基于所述温度采样信号执行对LED灯的温度保护操作的步骤包括以下至少一种：令所述LED灯中的开关电源基于所述温度采样信号降低所输出的供电功率；令所述LED灯中的调光模块基于所述温度采样信号调整所输出的调光信号，以在温度升高时降低LED灯的亮度；或者令设置在所述LED灯的待保护电路处的散热装置基于所述温度采样信号执行散热操作。
综上所述，本申请公开的温度采样装置、温度保护装置及方法、以及照明系统通过热敏电阻来感知LED负载电路的环境温度，并且通过降低输出功率的方式达到为LED负载电路降温的效果，成本低廉，节能且安全；另外温度采样装置可以直接与现有的LED照明系统中的开关电源本身具有的引脚相耦接，既不需要对LED照明系统中开关电源本身的电路进行更改，也不需要额外设计相适配的电路或芯片即可实现温度保护功能，通用性强。
附图说明
本申请所涉及的发明的具体特征如所附权利要求书所显示。通过参考下文中详细描述的示例性实施方式和附图能够更好地理解本申请所涉及发明的特点和优势。对附图简要说明书如下：
图1显示为本申请温度采样装置在一实施例中的电路方块示意图；
图2显示为本申请温度采样装置在一实施例中温度检测单元的电路结构示意图；
图3显示为本申请温度采样装置在另一实施例中温度检测单元的电路结构示意图；
图4显示为本申请温度采样装置在一实施例中的信号处理单元的电路方块示意图；
图5显示为本申请温度采样装置在一实施例中的信号处理单元的电路结构示意图；
图6显示为本申请温度采样装置在另一实施例中的信号处理单元的电路结构示意图；
图7显示为反馈模块的阻值Rfb与温度采样信号Vtem的信号量变化范围之间的变化曲线示意图；
图8显示为本申请温度采样装置在另一实施例中的电路方块示意图；
图9显示为本申请温度采样装置在一实施例中的电压跟随模块的电路架构示意图；
图10显示为本申请温度采样装置在另一实施例中的电压跟随模块的电路架构示意图；
图11显示为本申请温度采样装置在又一实施例中的电路方块示意图；
图12A显示为本申请温度采样装置在再一实施例中的电路方块示意图；
图12B显示为本发明一实施例的温度保护电路的电路结构示意图；
图12C显示为本发明另一实施例的温度保护电路的电路结构示意图；
图12D显示为本发明一实施例的温度保护信号Vtem与RNTC之间的关系曲线示意图；
图13显示为本申请温度保护装置在一实施例中的电路方块示意图；
图14显示为本申请温度保护装置在一实施例中的驱动模块的电路架构示意图；
图15显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图；
图16显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图；
图17显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图；
图18显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图；
图19显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图；
图20显示为本申请LED照明系统在一实施例中的电路方块示意图；
图21显示为本申请LED照明系统在一实施例中的开关电源的电路方块示意图；
图22显示为本申请LED照明系统在一实施例中的整流模块的电路架构示意图；
图23显示为本申请LED照明系统在一实施例中的滤波模块的电路架构示意图；
图24显示为本申请LED照明系统在另一实施例中的滤波模块的电路架构示意图；
图25显示为本申请LED照明系统在一实施例中的LED负载电路的架构示意图；
图26显示为本申请LED照明系统在另一实施例中的LED负载电路的架构示意图；
图27显示为本申请LED照明系统在一实施例中的启动保护电路的电路方块示意图；
图28显示为本申请LED照明系统在一实施例中的启动保护电路的电路架构示意图；
图29显示为本申请温度采集的方法在一实施例中的流程图；
图30显示为本申请LED灯的温度保护方法在一实施例中的流程图；以及
图31显示为热敏电阻的阻值随温度线性变化而变化的曲线示意图。
具体实施方式
以下由特定的具体实施例说明本申请的实施方式，熟悉此技术的人士可由本说明书所揭露的内容轻易地了解本申请的其他优点及功效。
在下述描述中，参考附图，附图描述了本申请的若干实施例。应当理解，还可使用其他实施例，并且可以在不背离本公开的精神和范围的情况下进行机械组成、结构、电气以及操作上的改变。下面的详细描述不应该被认为是限制性的，并且本申请的实施例的范围仅由公布的专利的权利要求书所限定。这里使用的术语仅是为了描述特定实施例，而并非旨在限制本申请。空间相关的术语，例如“上”、“下”、“左”、“右”、“下面”、“下方”、“下部”、“上方”、“上部”等，可在文中使用以便于说明图中所示的一个元件或特征与另一元件或特征的关系。
虽然在一些实例中术语第一、第二等在本文中用来描述各种元件或参数，但是这些元件或参数不应当被这些术语限制。这些术语仅用来将一个元件或参数与另一个元件或参数进行区分。例如，第一输入端可以被称作第二输入端，并且类似地，第二输入端可以被称作第二输入端，而不脱离各种所描述的实施例的范围。第一输入端和第二输入端均是在描述一个输入端，但是除非上下文以其他方式明确指出，否则它们不是同一个输入端。相似的情况还包括第一整流输出端与第二整流输出端，或者第一滤波输出端与第二滤波输出端。
再者，如同在本文中所使用的，单数形式“一”、“一个”和“该”旨在也包括复数形式，除非上下文中有相反的指示。应当进一步理解，术语“包含”、“包括”表明存在所述的特征、步骤、操作、元件、组件、项目、种类、和/或组，但不排除一个或多个其他特征、步骤、操作、元件、组件、项目、种类、和/或组的存在、出现或添加。此处使用的术语“或”和“和/或”被解释为包括性的，或意味着任一个或任何组合。因此，“A、B或C”或者“A、B和/或C”意味着“以下任一个：A；B；C；A和B；A和C；B和C；A、B和C”。仅当元件、功能、步骤或操作的组合在某些方式下内在地互相排斥时，才会出现该定义的例外。
另外，需先说明的是，本文为了明确说明本申请揭露的各个发明特点而以多个实施例的方式分就各实施例说明如下。但并非是指各个实施例仅能单独实施。熟悉本领域的技术人员可依据需求自行将可行的实施范例搭配在一起设计，或是仅将不同实施例中可带换的组件/模块依设计需求自行代换。换言之，本案所教示的实施方式不仅限于下列实施例所述的态样，更包含有在可行的情况下，各实施例/组件/模块之间的代换与排列组合，于此合先叙明。
电子元器件的应用范围十分广泛，不仅应用于一般工业，也广泛应用于交通运输、家用电器、电子装置用电源等。当电子元器件在以大功率工作、或长时间处于工作状态会产生热 量。当热量积聚而使得温度过高时，易导致电子元器件的寿命降低，或者使得一些对温度敏感的电子元器件失效，从而影响整个电子设备的正常工作。尤其是在家用电器中占有突出地位的照明设备，其在超过安全阈值的范围工作时，不仅会使得灯源本身的寿命大幅度降低而且使得驱动灯源工作的驱动器也性能下降，甚至损坏。
其中，电子元器件是电子元件和小型的机器、仪器的组成部分，其本身常由若干零件构成，电子元器件包括：电阻、电容、电感、电位器、电子管、散热器、机电元件、连接器、半导体器件、电声器件、激光器件、电子显示器件、光电器件、传感器、电源、开关、电子变压器、继电器、集成电路、各类电路等。
以开关电源为例，其作为进行电能转换的设备用于将市电所提供的交流电转换成低压直流电，具体可例如为电子设备的电源适配器、驱动器、或驱动芯片等。开关电源中的电子部件可能因受热而降低或失去效能。例如，电解电容里的电解液会因为温度过高而干枯，从而电解电容的容量减小或失效，以一个极限工作温度为85℃的电解电容为例，在温度为20℃的条件下工作时，一般情况可以保证181019小时的正常工作时间，而在极限温度85℃的条件下工作时，一般情况仅仅可以保证2000小时的正常工作时间。再如，二极管的伏安特性受温度的影响而产生变化，以室温26℃为参考，在二极管正向电流不变情况下，温度每升高1℃，正向压降减小2～2.5mV，温度每升高10℃，其反向电流约增大一倍。又如，电感线圈、变压器、扼流圈等的绝缘性能会随着温度的升高而下降。以LED负载电路为例，所述LED负载电路包含多个LED灯珠，当LED灯珠的温度超过100℃，其工作寿命将大大降低。
鉴于此，本申请提出一种温度采样装置、温度保护装置及方法、以及照明系统，以解决前述提到的问题，为使本申请的上述目的、特征和优点能够更为明显易懂，下面结合附图对本申请的具体实施例做详细的说明。下列本申请各实施例的叙述仅是为了说明而为例示,并不表示为本申请的全部实施例或将本申请限制于特定实施例。另外，相同的元件编号可用以代表相同、相应或近似的元件，并非仅限定于代表相同的元件。
在可能的实施方式中，本申请提出一种温度采样装置，以下结合图1至图12C对所提出的温度采样装置进行详细说明。请参阅图1，显示为本申请温度采样装置在一实施例中的电路方块示意图，如图所示，所述温度采样装置20包括温度检测单元21和信号处理单元22。温度检测单元21具有检测端Pi_210，温度检测单元21受待保护电路(未予以图示)的环境温度变化的影响而改变自身的阻值，以在检测端Pi_210输出检测信号Vdec。信号处理单元22耦接于检测端Pi_210，用于限制温度检测单元21中受阻值变化影响的检测信号Vdec，以在信号处理单元22的信号输出端Pi_220上输出与所述阻值变化对应的温度采样信号Vtem。
其中，所述待保护电路是指由电子元件搭建的电路结构，其受温度影响会改变自身电路特性、减少电路寿命、或损坏电路功能等，其中，所述电子元件包括但不限于：如电阻、电容、电感等基本元器件，以及如功率管、集成电路等半导体器件。所述待保护电路举例为前述提及的开关电源、电解电容、和LED负载电路中的至少一种等。
所述温度检测单元21整体的设置在待保护电路的附近，或者温度检测单元21中的热敏元件被设置在待保护电路附近，以感知待保护电路的温度。其中，所述温度检测单元21具有随所处环境的温度变化而改变其导电性(导电性反映了阻值的变化)的特性。根据配置于温度检测单元21中的对温度敏感的电子元件的特性，温度检测单元21所输出的检测信号Vdec既可能有随温度的线性变化而单调变化的特点，又可能出现在某个特定温度下的浪涌特性。为此，所述温度检测单元21所输出的检测信号Vdec反映温度的变化、或某个特定温度。
以温度检测单元21的阻值的变化与环境温度的变化之间具有单调性为例，其中，所述单调性表示阻值变化与环境温度变化之间的关系是同向的或反向的。所述单调性可以是基于线性关系的单调性，或者基于非线性关系的单调性。例如，温度检测单元21的阻值的变化与环境温度的变化具有系数K的比例关系。又如，请参阅图31，其显示为热敏电阻的阻值随温度线性变化而变化的曲线示意图，温度检测单元21的阻值的变化与环境温度的变化为非线性，在环境温度在不同区间内时，温度检测单元21的阻值随温度的变化程度不同，环境温度较低(图31中低于-10℃)或较高(图31中高于70℃)时，温度检测单元21的阻值随温度变化较为明显，在环境温度在正常范围(图31中30℃至60℃之间)时，温度检测单元21的阻值随温度变化不明显。另外，在一示例中，温度检测单元21的阻值变化与环境温度变化之间的关系是同向的，例如，随着环境温度的升高，阻值增大，或者随着环境温度的减小，阻值减小；在另一示例中，温度检测单元21阻值变化与环境温度变化之间的关系是反向的，例如，随着环境温度的升高，阻值减小，或者随着环境温度的减小，阻值增大。
需要说明的是，上述单调性并非一定在所有温度范围内都适用或都可测量。例如LED灯珠在常温-某一阈值温度的范围内变化时，所述温度检测单元21中阻值的变化可忽略，或者温度检测单元21被当作具有固定阻值的电路结构来使用；当LED灯珠的环境温度达到相应阈值温度以上的某一温度范围时，温度检测单元21所呈现的阻值随温度变化而单调变化的特性更易于测量。上述提及的阻值的变化与环境温度的变化之间具有单调性的电路特性可视为至少使温度保护电路正常工作期间而呈现的电路特性。
请参阅图2，显示为本申请温度采样装置在一实施例中温度检测单元的电路结构示意图，如图所示，所述温度检测单元21包括串联的热敏电阻R21_2和分压电阻R21_1，所述热敏电 阻R21_2的一端耦接检测端Pi_210，另一端接地GND，分压电阻R21_1的一端耦接供电电源VCC，另一端耦接热敏电阻R21_2的一端。
在一示例中，所述热敏电阻R21_2为负温度系数热敏电阻(Negative Temperature Coefficient，NTC)，根据图2所示的电路结构，温度检测单元21的工作原理为：当环境温度升高时，热敏电阻R21_2受环境温度升高而降低阻值，检测端Pi_210上的检测信号Vdec为热敏电阻R21_2获取的供电电源VCC的分压，由于热敏电阻R21_2阻值的降低，所以检测信号Vdec降低；对应地，当环境温度降低时，检测信号Vdec升高。在另一示例中，所述热敏电阻R21_2为正温度系数热敏电阻(Positive Temperature Coefficient，PTC)，根据图2所示的电路结构，温度检测单元21的工作原理为：当环境温度升高时，热敏电阻R21_2受环境温度升高而增大阻值，检测端Pi_210上的检测信号Vdec为热敏电阻R21_2获取的供电电源Vcc的分压，由于热敏电阻R21_2阻值的增大，所以检测信号Vdec升高；对应地，当环境温度降低时，检测信号Vdec降低。
请参阅图3，显示为本申请温度采样装置在另一实施例中的温度检测单元电路结构示意图，如图所示，所述温度检测单元21包括串联的热敏电阻R21_3和分压电阻R21_4，所述热敏电阻R21_3的一端耦接检测端Pi_210，另一端接供电电源Vcc，分压电阻R21_4的一端接地GND，另一端耦接热敏电阻R21_3的一端。
在一示例中，所述热敏电阻R21_3为负温度系数热敏电阻NTC，根据图3所示的电路结构，温度检测单元21的工作原理为：当环境温度升高时，热敏电阻R21_3受环境温度升高而降低阻值，检测端Pi_210上的检测信号Vdec为分压电阻R21_4获取供电电源VCC的分压，由于总阻值(分压电阻的阻值214与热敏电阻R21_3的阻值之和)的降低，所以分压电阻R21_4获取的供电电源Vcc的分压升高，因此检测信号Vdec升高；对应地，当环境温度降低时，检测信号Vdec降低。在另一示例中，所述热敏电阻R21_3为正温度系数热敏电阻PTC，根据图3所示的电路结构，温度检测单元21的工作原理为：当环境温度升高时，热敏电阻R21_3受环境温度升高而增大阻值，检测端Pi_210上的检测信号Vdec为分压电阻R21_4获取供电电源Vcc的分压，由于总阻值(分压电阻的阻值214与热敏电阻R21_3的阻值之和)的增大，所以分压电阻R21_4获取的供电电源Vcc的分压降低，因此检测信号Vdec降低；对应地，当环境温度降低时，检测信号Vdec升高。
由上述可知，通过温度检测单元21中热敏电阻R21_2或R21_3具有随温度变化而改变阻值的特性，使得所述检测信号Vdec是随温度检测单元21的阻值的变化而单调变化。
为了防止因检测信号Vdec的变化过快以及变化范围过大而使得后续电路不便于响应温 度保护措施，在图1所示的实施例中，所述温度检测单元21的检测端Pi_210上还耦接有信号处理单元22，信号处理单元22用于限制所述温度检测单元21中受所述阻值变化影响的检测信号Vdec，从而在检测信号Vdec受到限制的情形下输出与所述阻值变化对应的温度采样信号Vtem。也即，信号处理单元22通过限制检测信号Vdec的变化范围，使得在同一环境温度变化范围内，检测信号Vdec的信号量变化范围由未限制前的[a1,b1]范围缩小至限制后的[c1,d1]范围。在宏观上测量，缩限后的信号量变化范围[c1,d1]可被视为基本上未发生变化。缩限后的信号量变化范围可能不易被检测，但信号处理单元22会予以响应。所述信号处理单元22对经限制的检测信号Vdec进行信号处理，使得温度采样装置所输出的温度采样信号Vtem的变化与阻值的变化之间仍具有单调性。其中，所述单调性表示温度检测单元21的阻值变化与温度采样信号Vtem变化之间的关系是同向的或反向的。在一示例中，阻值变化与温度采样信号Vtem变化之间的关系是同向的，例如，随着阻值的增大，温度采样信号Vtem升高，或者随着阻值的降低，温度采样信号Vtem减小；在另一示例中，阻值变化与温度采样信号Vtem变化之间的关系是反向的，例如，随着阻值的增大，温度采样信号Vtem减小，或者随着阻值的降低，温度采样信号Vtem升高。
请参阅图4，显示为本申请温度采样装置在一实施例中的信号处理单元的电路方块示意图，如图所示，所述信号处理单元22包括放大模块222和反馈模块221。所述放大模块222具有输入端Pi_221、参考端Pi_222、以及输出端Pi_220，其输入端Pi_221耦接温度检测单元的检测端Pi_210，其参考端Pi_222接入第一参考信号Vref1，其输出端即为所述信号处理单元22的输出端Pi_220，用于输出温度采样信号Vtem。所述反馈模块221耦接于所述输出端Pi_220与检测端Pi_210之间。所述反馈模块221根据所述温度采样信号Vtem而形成的反馈信号FB反馈至所述检测端Pi_210，以限制所述检测信号Vdec的变化，所述放大模块222基于经限制的检测信号Vdec，对其输入端Pi_221所接收的信号进行放大处理，从而输出温度采样信号Vtem。其中，输入端Pi_221所接收的信号例如为基于经限制的检测信号Vdec而形成的电流信号，所述第一参考信号Vref1为一参考低电位，例如，电源地GND或接基准地SGND。
具体地，所述温度采样信号Vtem是在检测信号Vdec被反馈模块221限制后形成的，从而根据反馈模块221能够确定温度检测单元21的阻值变化范围对应于预设的温度采样信号的信号量的变化范围。在一些实施例中，所述反馈模块221例如为一电阻(未予以图示)，此时，反馈模块221根据温度采样信号Vdec而形成的反馈信号FB为温度采样信号Vdec流经该电 阻的电流。故而，请参阅图7，其显示为反馈模块的阻值Rfb与温度采样信号Vtem的信号量变化范围之间的变化曲线示意图，如图所示，反馈模块221为电阻时的阻值Rfb相关于温度检测单元21的阻值变化范围对应的预设温度采样信号Vtem的信号量变化范围，请结合图2、图3、和图4，以待保护电路的环境温度在80℃-100℃之间，温度检测单元21中热敏电阻R21_2为NTC(或热敏电阻R21_3为PTC)，且热敏电阻R21_2(或热敏电阻R21_3)的阻值的变化范围在12KΩ-6.5KΩ之间为例，在反馈模块221的电阻的阻值为100KΩ时，则预设的温度采样信号的信号量的变化范围是0.5V-7.2V；在反馈模块221的电阻的阻值为150KΩ时，则预设的温度采样信号的信号量的变化范围是0.6V-8.5V；在反馈模块221的电阻的阻值为200KΩ时，则预设的温度采样信号的信号量的变化范围是0.7V-9V。在其他实施例中，所述反馈模块221也包含由多个阻性器件等效而成电阻的电路结构，例如，所述反馈模块221包含多个串联/并联的电阻，此时，反馈模块221的等效阻值相关于温度检测单元21的阻值变化范围对应的预设温度采样信号的信号量变化范围。
请参阅图5，显示为本申请温度采样装置在一实施例中的信号处理单元的电路结构示意图，如图所示，所述信号处理单元包括反馈模块221、放大模块222、以及电阻R222_1。其中，反馈模块221的一端耦接放大模块222的输出端Pi_220，另一端耦接输入端Pi_221。放大模块222包括三极管Q1，三极管Q1的第一端耦接于输出端Pi_220，其第二端耦接于参考端Pi_222，其控制端耦接于输入端Pi_221，为了给所述放大模块222供电以及使得其输出端Pi_220能够正常输出温度采样信号Vtem，三极管Q1的第一端还经电阻R222_1耦接于一电源Vcc。需要说明的是，所述三极管Q1的控制端和放大模块222的输入端Pi_221之间还可耦接一电阻R222_2，以保护三极管Q1免受较大的电流冲击。三极管Q1的第二端与参考端Pi_222之间还可耦接一电阻R222_3以稳定三极管Q1的静态工作点。其中，由于电阻R222_2和电阻R222_3是非必要的元器件，故图5中以虚线示之，并且电阻R222_3相较于电阻R222_1来说阻值可忽略，以数量级来看，电阻R222_3为欧姆级，而电阻R222_1为千欧姆级。
其中，三极管Q1可以采用NPN型或PNP型。例如，在图2所示的温度采集单元21的电路架构中的热敏电阻R21_2采用NTC时，或者图3所示的温度采集单元21的电路架构中热敏电阻R21_3采用PTC时，图5中所示的三极管Q1为NPN型。又如，在图2所示的温度采集单元21的电路架构中的热敏电阻R21_2采用PTC时，或者图3所示的温度采集单元21的电路架构中热敏电阻R21_3采用NTC时，三极管Q1可以采用PNP型，当然，采用PNP型三极管时，需要依据PNP型三极管的连接方式对图5中的三极管Q1的连接方式做适应性 调整。在实际应用中，本领域技术人员可以根据温度采样单元21的电路架构对三极管Q1的型号进行选择。
以下以温度检测单元21采用图2所示的电路架构且热敏电阻R21_2采用NTC为例，并结合图5说明信号处理单元22的工作过程。当所述待保护电路的温度升高时，热敏电阻R21_2的阻值变小，检测信号Vdec瞬时变小，从而三极管Q1的控制电流Ib变小，又由于三极管Q1工作在放大状态(处于放大状态的原因容后详述)，所以在此时，输出端Pi_220输出的温度采样信号Vtem变大(因为Vtem＝Vcc–β*Ib*R222_1)。为了防止检测信号Vdec的变化过快以及变化范围过大，而导致输出的温度采样信号Vtem不能被限制在一定的预设范围内，从而使得后续电路不便于响应温度保护措施，在放大模块222的输出端Pi_220与输入端Pi_221之间耦接反馈模块221，以限制检测信号Vdec的变化。以反馈模块221为一电阻为例，其将获取到的温度采样信号Vdec流经电阻的电流作为反馈信号FB，通过放大模块222的输入端Pi_221反馈给温度检测单元21的检测端Pi_210。由于温度采样信号Vtem变大，作为反馈信号FB电流也增大，从而使得流过热敏电阻R21_2电流增大，从而限制了上述中检测信号Vdec的瞬时变小。也即，上述过程中，忽略三极管Q1的控制电流Ib(因为控制电流Ib较小)，则流过反馈模块221的电流与流过温度检测单元21的电阻R21_1的电流之和与流过热敏电阻R21_2的电流相等，等式
Figure PCTCN2020135541-appb-000001
成立，其中R221为反馈模块221的电阻，忽略上述过程中检测信号Vdec的微小变化，则上述过程中，随着热敏电阻R21_2的阻值的减小(或升高)，温度采样信号Vtem也随之在预设的变化范围内增大(或变小)。
以上说明仅仅为图2所示的电路架构中热敏电阻R21_2采用NTC一种示例，在热敏电阻R21_2为PTC时，信号处理单元22的工作原理与上述类似，所不同之处仅在于，随着热敏电阻R21_2的阻值的减小(或增大)，温度采样信号Vtem也随之在预设的变化范围内减小(或增大)。
另外，温度检测单元21也可采用图3所示的电路架构，此时，信号处理单元22的工作原理与也上述类似，所不同之处仅在于，在热敏电阻R21_3采用PTC，随着热敏电阻R21_3的阻值的减小(或增大)，温度采样信号Vtem也随之在预设的变化范围内增大(或变小)，在热敏电阻R21_3采用NTC时，随着热敏电阻R21_3的阻值的减小(或升高)，温度采样信号Vtem也随之在预设的变化范围内减小(或增大)。
当使用如图5所示的实施例中的放大模块222对控制电流Ib的进行放大处理时，由于控 制电流Ib较小，这使得放大模块222由于放大倍数不足而输出的温度采样信号Vtem随温度检测单元21的阻值的变化不明显，不利于温度保护装置捕捉或根据温度采样信号的信号量而执行相应的温度保护操作。因此，在另一实施例中，为了增加放大倍数，所述信号处理单元中的放大模块包括至少两个级联的三极管，第一级三极管的控制端耦接所述检测端，最后一级三极管接入所述放大模块的参考端与输出端之间电路中。
请参阅图6，显示为本申请温度采样装置在另一实施例中的信号处理单元的电路结构示意图，如图所示，所述信号处理单元包括反馈模块221、放大模块222、电阻R222_4、以及电阻R222_5。其中，反馈模块221的一端耦接放大模块222的输出端Pi_220，另一端耦接输入端Pi_221。所述放大模块222包括两个级联的三极管Q2和Q3，其中，三极管Q2为第一级三极管，三极管Q3为最后一级三极管。三极管Q3的第一端耦接于放大模块222的输出端Pi_220，其第二端耦接于放大模块222的参考端Pi_222，并且三极管Q3通过其控制端耦接于三极管Q2的第二端。三极管Q2的控制端耦接于放大模块222的输入端Pi_221，为了给所述放大模块222供电以及使得其输出端Pi_220能够正常输出温度采样信号Vtem，所述三极管Q2的第一端经电阻R222_5耦接于电源Vcc，三极管Q3的第一端还经电阻R222_4耦接于电源Vcc。需要说明的是，所述三极管Q2的控制端和放大模块222的输入端Pi_221之间还可耦接一电阻R222_6，以保护三极管Q2免受较大的电流冲击。三极管Q3的第二端与参考端Pi_222之间还可耦接一电阻R222_7以稳定三极管Q3的静态工作点。其中，由于电阻R222_6和电阻R222_7是非必要的元器件，故图6中以虚线示之，并且电阻R222_7相较于电阻R222_4来说阻值可忽略，以数量级来看，电阻R222_7为欧姆级，而电阻R222_4为千欧姆级。
其中，三极管Q2和Q3可以采用NPN型或PNP型。例如，在图2所示的温度采集单元21的电路架构中的热敏电阻R21_2采用NTC时，或者图3所示的温度采集单元21的电路架构中热敏电阻R21_3采用PTC时，图6所示的三极管Q2和Q3为NPN型。又如，在图2所示的温度采集单元21的电路架构中的热敏电阻R21_2采用PTC时，或者图3所示的温度采集单元21的电路架构中热敏电阻R21_3采用NTC时，图6所示的三极管Q2和Q3采用PNP型，当然，采用PNP型三极管时，需要依据PNP型三极管的连接方式对图6中的三极管Q2和Q3的连接方式做适应性调整。在实际应用中，本领域技术人员可以根据温度采样单元21的电路架构对三极管Q2和Q3的型号进行选择。
图6所示的两级三级管的电路结构仅仅为一种示例，并不是对放大模块222的级数的限制。在实际应用中，本领域技术人员也可根据需求在三极管Q2和三极管Q3之间适当的增加 三极管的个数。另外，图6所示的信号处理单元的工作原理与包含图5所示的信号处理单元的工作原理相同，不同之处仅在于，对信号的放大倍数不同，在此不做赘述。
前述各示例利用三极管的线性放大区对经限制的检测信号Vdec进行放大处理。在另一些示例中，也可以使用运算放大器实现放大作用，本领域技术人员可以依据运算放大器的工作原理对电路进行适应性修改和连接，在此不再赘述。
按照上述各实施例的描述，所述温度采样装置实现了将随温度变化而变化的阻值转换成在预设信号量范围内对应的温度采样信号的目的。
结合图2和图5所提供的温度采样装置的电路结构，以及图31所提供的阻值随温度变化的曲线示意图，其中，温度检测单元21中的热敏电阻R21_2为NTC，在热敏电阻R21_2所处的环境温度较低时其电阻较高，这使得图2所示的检测信号Vdec的电压值较高，其使得信号处理单元中的三极管Q1(NPN型)处于饱和状态，三极管Q1完全导通，电源Vcc直接经电阻R222_1、三极管Q1、以及电阻R222_3流入参考端Pi_222，输出端Pi_220输出为零或近似为零，信号处理单元22的反馈模块221对检测信号Vdec无限制作用。在待保护电路的环境温度升高到起始保护温度时，检测信号Vdec也由于热敏电阻R21_2的减小而减小到使得三极管Q1处于放大状态(例如，检测信号Vdec减小到0.6V)，开始以前述实施例中所描述的工作原理工作，反馈模块221将检测信号Vdec限制在如0.6V附近，输出端Pi_220输出与所述热敏电阻R21_2变化对应的温度采样信号Vtem。若待保护电路的环境温度继续升高，热敏电阻R21_2的阻值继续减小，检测信号Vdec继续减小，使得三极管Q1处于截止状态，则温度采样信号Vtem不随阻值的变化而变化。
需要说明的是，热敏电阻R21_2或R21_3的阻值与温度之间的变化与其类型和性能有关，若热敏电阻R21_2或R21_3为PTC类型，则对应的阻值随温度变化曲线与图31相反，即PTC类型的热敏电阻的阻值随温度升高而增大。可借鉴地，由于信号处理单元22中包含有上述三种状态的半导体器件，故而，半导体器件根据所接收的电信号的变化也将在三种状态之间转换。这使得温度采样装置可以在待保护电路需要提供温度保护时提供温度采样信号。仍以结合图2和图5的电路结构为例，其中，热敏电阻R21_2为PTC，三极管Q1采用为PNP型，当待保护电路的环境温度较低时，热敏电阻R21_2的阻值较小，使得检测信号Vdec也较小，从而使得三极管Q1处于饱和状态而完全导通，输出端Pi_220输出为零或近似为零，信号处理单元22处于第一状态。在待保护电路的环境温度升高到起始保护温度时，检测信号Vdec也由于热敏电阻R21_2的升高而升高到使得三极管Q1处于放大状态，信号处理单元22进入 第二状态。另外，温度采集单元21也可采用图3所示的电路架构，此时，信号处理单元22的工作原理与上述类似，在此不做赘述。
图6所示的信号处理单元22从第一状态转入第二状态的工作过程与图5所示的电路架构对应的从第一状态转入第二状态的工作过程类似，所不同之处在于，在待保护电路的环境温度升高到起始保护温度时，由于图6的放大模块222包括两个级联的三极管Q2和Q3，所以图6的三极管Q2和Q3由饱和状态转入放大状态的检测信号Vdec的值与图5不同。例如，在图6中，检测信号Vdec降低到1.2V使得三极管Q2和Q3处于放大状态，信号处理单元22进入第二状态，图6中的反馈模块221将检测信号Vdec限制在1.2V附近，输出端Pi_220输出与所述温度检测单元21的阻值变化对应的温度采样信号Vtem。
以待保护电路为LED灯中的电路结构为例，当LED灯工作在正常工作温度范围内时，温度采样装置输出的温度采样信号不会触发后续温度保护装置的温度保护操作，如温度采样信号的信号类型、信号值等不会触发温度保护操作；或者，温度采样装置不予输出温度采样信号而不会触发温度保护操作。当环境温度达到起始保护温度时(如80℃)时，温度采样装置输出反映温度变化的温度采样信号。也即，上述各实施例中的信号处理单元22是在待保护电路的环境温度转入起始保护温度时，基于检测信号的变化而从第一状态转入第二状态的，在第二状态期间，所述信号处理单元22产生所述温度采样信号Vtem。其中，第一状态为信号处理单元22还未被启动的状态、或者根据信号处理单元22中的半导体器件处于截止状态/导通状态而处于不提供有效输出的状态；第二状态为信号处理单元22被启动的状态、或者根据信号处理单元22中的半导体器件处于线性放大状态而处于提供有效输出的状态。
请参阅图8，显示为本申请温度采样装置在另一实施例中的电路方块示意图，所述温度采样装置20在图1的基础上，还包括输出单元23，输出单元23耦接信号处理单元22的输出端Pi_220以将接收的温度采样信号Vtem输出。
在此，输出单元23可以起到将温度采样装置与后级电路进行信号隔离的作用，其包含电容、或三极管等具有隔离作用的电路结构。
在一些实施例中，所述输出单元23包括电压跟随模块(未予以图示)，其输入端耦接所述信号处理单元的输出端，参考端接收第二参考信号，以及所述电压跟随模块的输出端输出所述温度采样信号。
请参阅图9，显示为本申请温度采样装置在一实施例中的电压跟随模块的电路架构示意图，如图所示，所述电压跟随模块包括电压跟随器231，电压跟随器231的第一输入端作为 电压跟随模块的输入端Pi_230而耦接于信号处理单元22的输出端Pi_220，其第二输入端作为电压跟随模块的参考端Pi_231耦接于电压跟随器231的输出端，以电压跟随器231的输出作为第二参考信号，而电压跟随器231的输出端作为电压跟随模块的输出端Pi_232使用。
图9所示的电压跟随模块由于采用的是电压跟随器231，所述电压跟随器231的放大倍数为1或接近于1，所以电压跟随模块在输出端Pi_232上的输出跟随电压跟随模块在输入端Pi_230接收到的温度采样信号Vtem，也即，输出端Pi_232上的输出与电压跟随模块在输入端Pi_230接收到的温度采样信号Vtem相同或近似，因此，在此视为图9所示的电压跟随模块上输出温度采样信号Vtem。
请参阅图10，显示为本申请温度采样装置在另一实施例中的电压跟随模块的电路架构示意图，如图所示，所述电压跟随模块包括三极管Q4，三极管Q4的控制端耦接于电压跟随模块的输入端Pi_230，第一端耦接电压跟随模块的参考端Pi_231以接收电源Vcc作为第二参考信号给三极管Q4供电，三极管Q4的第二端经一电阻R23_1接入一参考低电位(参考低电位为电源地GND或SGND，图10中以电源地GND示出)，同时三极管Q4的第二端耦接电压跟随模块的输出端Pi_232以输出温度采样信号Vtem。
具体地，三极管Q4在其控制端接收到由电压跟随模块的输入端Pi_230输入的温度采样信号Vtem，该温度采样信号会使得三极管进入放大状态，此时，三极管Q4的控制端与第二端之间的PN结已处于导通状态，这一PN结导通后压降大小基本不变。这样，控制端的温度采样信号Vtem升高时第二端输出的信号也升高，控制端的温度采样信号Vtem下降时第二端输出的信号也下降，显然第二端的信号随温度采样信号Vtem的变化而变化，所以在电压跟随模块的输出端Pi_232输出温度采样信号Vtem。
请参阅图11，显示为本申请温度采样装置在又一实施例中的电路方块示意图，如图所示，所述温度采样装置在图1的基础上，还包括滤波单元24，耦接信号处理单元22的输出端Pi_220，用于对温度采样信号Vtem进行滤波，以去除温度采样信号Vtem的噪声。其中，所述滤波单元24可例如为以滤波电容(未予以图示)，滤波电容的一端耦接信号处理单元22的输出端Pi_220，另一端耦接一参考低电位，所述参考低电位可为电源地GND或基准地SGND，图中以电源地GND示出。
请参阅图12A，显示为本申请温度采样装置在再一实施例中的电路方块示意图，如图所示，所述温度采样装置在图10的基础上，还包括滤波单元24，耦接输出单元23的输出端Pi_232，用于对输出单元23输出的温度采样信号Vtem进行滤波，以去除温度采样信号Vtem的噪声。 其中，所述滤波单元24可例如为一滤波电容(未予以图示)，滤波电容的一端耦接输出单元23的输出端Pi_232，另一端耦接一参考低电位，所述参考低电位可为电源地GND或基准地SGND，图中以电源地GND示出。
上述各实施例中所述的温度采样装置输出的温度采样信号Vtem用于向温度保护装置传输，以使得温度保护装置能够响应于温度采样信号Vtem对待保护电路进行降温。例如，温度保护装置可为一散热风扇，散热风扇根据温度采样信号Vtem启动以对待保护电路散热；又如，温度保护装置为电源中的驱动模块，驱动模块基于温度采样信号Vtem的大小来调整其输出功率以减少热量的产生，从而保证待保护电路的正常工作。但并不一次为限，温度保护装置可以为任何可基于温度采样信号Vtem而调整待保护电路的环境温度的装置。
以上各实施例中提出的温度采样装置通过热敏电阻来感知待保护电路的环境温度，成本低廉；另外温度采样装置可以直接与温度保护装置直接耦接，既不需要额外设计相适配的电路，也不需要更改现有的温度保护装置的内部构造，通用性强。
在其他实施例中，开关电源可被称为电源模块，LED负载电路可被称为LED模块，温度采样装置可被称为温度保护电路，温度采样信号Vtem可被称为温度保护信号Vtem，负温度系数热敏电阻可简称为NTC。
参考图12B显示为本发明一实施例的温度保护电路的电路结构示意图。温度保护电路20包含电阻R21_1、R221_1、R222_1、R222_2和R222_3，三极管Q1和NTCR21_2。电阻R21_1第一引脚电性连接至电阻R222_1的第一引脚，其第二引脚电性连接至NTCR21_2的第一引脚。电阻R221_1的第一引脚和电阻R222_2的第一引脚电性连接并连接至电阻R21_1的第二引脚。电阻R222_1的第二引脚电性连接至电阻R221_1的第二引脚。三极管Q1的基极(b极)电性连接至电阻R222_2的第二引脚，其集电极(c极)电性连接至电阻R221_1的第二引脚，其发射极(e极)电性连接至电阻R222_3的第一引脚。电阻R222_3的第二引脚电性连接至NTCR21_2的第二引脚并电性连接至电路节点GND。电阻R21_1的第一引脚电性连接至温度保护电路的输入端，用以接收电压输入信号Vcc，三极管Q1的集电极(c极)电性连接至温度保护电路的输出端，用以输出温度保护信号Vtem。
本实施例中NTCR21_2为负温度系数热敏电阻，其在不同的温度下具有不同的电阻值。其中，当温度越高时，其阻值越小。
下面描述温度保护电路20的动作原理。NTCR21_2用于感测温度，并将温度变化转化为自身的阻值变化。NTCR21_2的阻值变化反映在电路中，将影响输出的温度保护信号Vtem。 由于三极管Q1的b极输入阻抗较大，类似于运算放大器的电路原理，可以将三极管Q1的b极等效成虚断，电阻R21_1的第一引脚处的电压V1近似的等于三极管Q1的开启电压Von，电路的电流关系满足以下关系式：
I1+I2＝I3             式1
即流经电阻R21_1的电流I1加上流经电阻R221_1的电流I2等于流经NTCR21_2的电流I3。
将电路中各节点的电压和电阻代入式1可得到如下关系式：
Figure PCTCN2020135541-appb-000002
式中，R21_1为电阻R21_1的阻值，R221_1为电阻R221_1的阻值，R21_2为NTCR21_2的阻值，Vtem为温度保护信号，Vcc为温度保护电路20的输入电压信号，V1为电阻R21_1的第二引脚处的节点电压。V1等于三极管Q1的开启电压,约为0.6V。
通过上述关系式，可以得到温度保护信号Vtem与NTCR21_2的阻值之间的关系。
参考图12D显示为本发明一实施例的温度保护信号Vtem与RNTC之间的关系曲线示意图。图中，横坐标为NTCR21_2的阻值，纵坐标为温度保护信号Vtem。由图可知，当NTC的阻值增大时，温度保护信号Vtem减小。
电阻R21_1用以设定温度保护电路20开始输出温度保护信号Vtem的起始温度。
电阻R21_1和NTC的阻值满足下列关系式：
Vin*R ON/(R21_1+R ON)≈Von式3
式中，R ON为所述起始温度对应的NTC的阻值，R21_1为电阻R21_1的阻值,Vcc为输入电压，Von为三极管Q1的开启电压，约为0.6V。
通过改变关系式3中电阻R21_1的阻值便可设定温度保护电路20的开始输出温度保护信号Vtem的起始温度。其中当LED灯的工作温度大于所述起始温度时，温度保护电路20开始输出温度保护信号。
通过本实施例的公开，NTCR21_2的感测到的温度信号便可以转化为自身的阻值，然后通过温度保护电路20将所述温度信号转化为对应的温度保护信号Vtem。
参考图12C显示为本发明另一实施例的温度保护电路的电路结构示意图。温度保护电路20包含电阻R21_1、R221_2、R222_5、R222_4、R222_6、R222_7和R23_1，电容C25_1和C24_1，三极管Q2、Q3和Q4,以及NTCR21_2。电阻R21_1第一引脚电性连接至电阻R222_5 的第一引脚和电阻R222_4的第一引脚。NTCR21_2的第一引脚电性连接至电阻R21_1的第二引脚，其第二引脚电性连接至电路节点GND。电阻R221_2的第一引脚与电阻R222_6的第一引脚电性连接并电性连接至电阻R21_1的第二引脚。三极管Q2的b极电性连接至电阻R222_6的第二引脚，其c极电性连接至电阻R222_5的第二引脚。三极管Q3的b极电性连接至三极管Q2的e极，其c极电性连接至电阻R222_4的第二引脚，其e极电性连接至电阻R222_7的第一引脚。电阻R222_7的第二引脚电性连接至电路节点GND,电容C25_1的第一引脚电性连接至电阻R221_2的第一引脚，其第二引脚电性连接至电路节点GND。三极管Q4的b极电性连接至电子R221_2的第二引脚和电阻R222_4的第二引脚，其c极电性连接至电阻R21_1的第一引脚，其e极电性连接至电阻R23_1的第一引脚和电容C24_1的第一引脚。电阻R23_1的第二引脚电性连接至电容C24_1的第二引脚并电性连接至电路节点GND。
Vcc为温度保护电路20输入端的输入电压，Vtem为温度保护电路20输出的温度保护信号，V1为电阻R21_1第二引脚处的节点电压，Vtem1为电阻R222_4的第二引脚处的节点电压。
与图12B所示的实施例类似，本实施例的温度保护电路20用以采集LED灯的工作温度并将此温度信号转化为温度保护信号Vtem。与之不同的是，本实施例中增加了三极管Q3。三极管Q2和三极管Q3用于实现两级放大，增加电路的稳定性。三极管Q4与电阻R23_1构成电压跟随器，温度保护信号Vtem相较于Vtem1具有更强的驱动能力。电容C24_1用以对温度保护信号Vtem进行滤波。
同样的，电路节点信号Vtem1与NTCR21_2的电阻R NTC满足如下关系式：
Figure PCTCN2020135541-appb-000003
式中，R21_1为电阻R21_1的阻值，R221_2为电阻R221_2的阻值，R21_2为NTCR21_2的阻值，Vtem1为电阻R222_4的第二引脚处的节点电压，Vcc为温度保护电路20的输入电压信号，V1为电阻R21_1的第二引脚出处的电压。
本实施例中，V1为三极管Q2和三极管Q3的开启电压之和，约为1.2V。Vtem和Vtem1近似相等。
由关系式4可得出温度保护信号Vtem与NTCR21_2的阻值的关系。
电容C25_1用以实现LED灯的缓启动，即LED灯在上电后缓慢亮起。LED灯从上电到正常点亮亮度的时间取决于电容C25_1的大小。其中，电容C25_1的值越小，LED灯启动的 越快。
在其他实施例中，热敏电阻NTCR21_2可以由热敏电阻PTC替代。当使用热敏电阻PTC时，温度保护信号Vtem与热敏电阻的采样温度呈现负相关，即所述采样温度越高，温度保护信号Vtem越小。
在可能的实施方式中，本申请还提出一种温度保护装置，请参阅图13，显示为本申请温度保护装置在一实施例中的电路方块示意图，如图所示，所述温度保护装置30包括温度采样装置31以及温度保护单元32。所述温度采样装置31用于检测待保护电路(未予以图示)的环境温度并输出温度采样信号Vtem，温度保护单元32耦接于所述温度采样装置31以获得所述温度采样信号Vtem，为待保护电路提供与所述环境温度变化相应的温度保护操作。
其中，其中，所述待保护电路是指由电子元件搭建的电路结构，其受温度影响会改变自身电路特性、减少电路寿命、或损坏电路功能等，其中，所述电子元件包括但不限于：如电阻、电容、电感等基本元器件，以及如功率管、集成电路等半导体器件。
以开关电源为例，开关电源作为进行电能转换的设备用于将市电所提供的交流电转换成低压直流电，具体可例如为电子设备的电源适配器、驱动器、或驱动芯片等。开关电源中的电子部件可能因受热而降低或失去效能。例如，电解电容里的电解液会因为温度过高而干枯，从而电解电容的容量减小或失效，以一个极限工作温度为85℃的电解电容为例，在温度为20℃的条件下工作时，一般情况可以保证181019小时的正常工作时间，而在极限温度85℃的条件下工作时，一般情况仅仅可以保证2000小时的正常工作时间；再如，二极管的伏安特性受温度的影响而产生变化，以室温26℃为参考，在二极管正向电流不变情况下，温度每升高1℃，正向压降减小2～2.5mV，温度每升高10℃，其反向电流约增大一倍；又如，电感线圈、变压器、扼流圈等的绝缘性能会随着温度的升高而下降。以LED负载电路为例，所述LED负载电路包含多个LED灯珠，当LED灯珠的温度超过100℃，其工作寿命将大大降低。
温度采样装置31整体设置在待保护电路的附近，或者温度检测单元21中的热敏元件被设置在待保护电路附近，以感知待保护电路的温度，温度采样装置31为如前图1至图12C实施例中任一实施例所述的温度采样装置20，其电路架构以及工作原理请参阅针对图1至图12C的说明，在此不做赘述。
其中，驱动模块为通过控制电能转换将外部输入信号转换为适合于负载工作的电信号的装置，其负载可以为各种电子设备以及家用电器。在一些实施例中，所述驱动模块采用开关电源、驱动控制电路、或驱动控制芯片实现，其中所述驱动控制电路具有反馈引脚以接收温 度采样信号Vtem。但并不以此为限，驱动模块也可为其他具有控制电能转换的电路结构，例如：驱动模块可包括基于BUCK电路架构而构建的电路结构、基于BOOST电路架构而构建的电路结构、及基于BOOST-BUCK电路架构而构建的电路结构中的任一种。
请参阅图14，显示为本申请温度保护装置在一实施例中的驱动模块的电路架构示意图，如图所示，所述驱动模块包括驱动控制电路321，所述驱动控制电路321具有反馈引脚CS、输出引脚GT、以及接地引脚GND。驱动控制电路321的接地引脚GND耦接电源地GND，其反馈引脚CS一方面耦接一负载反馈端Pi_320以接收反映负载供电的反馈信号Vfb，另一方面耦接所述温度采样装置31的输出端Pi_310(输出端Pi_310可对应于图1至图6、以及图11中的Pi_220，或图8至图10、以及图12A中的Pi_232)以获取温度采样信号Vtem，其输出引脚GT用于与受控电路(未予以图示)耦接，驱动控制电路321根据反馈信号Vfb和温度采样信号Vtem在其输出引脚GT上输出控制信号，以使得受控电路根据控制信号降低负载的功率。
需要说明的是，温度采样信号Vtem来自于温度采样装置31，而反馈信号Vfb反映的是负载供电，其来自于受控电路，因此，温度采样信号Vtem是区别于反馈信号Vfb的。所述受控电路为受控于所述驱动控制电路321为负载提供供电的电路，例如，受控电路包括耦接于所述输出引脚GT的开关电路和与开关电路相耦接的功率转换电路，其中，开关电路受控于所述驱动控制电路321进行通断以控制功率转换电路进行能量转换，使得功率转换电路输出负载供电信号以为负载供电。
进一步地，也可将开关电路作为驱动模块的一部分，请参阅图15，显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图，如图所示，在图14的基础上，所述驱动模块还包括开关电路322，所述开关电路322耦接于驱动控制电路321的输出引脚GT，从而驱动控制电路321通过其输出引脚GT向开关电路322输出随温度采样信号Vtem变化而变化的控制信号，开关电路322基于该控制信号调整其开关频率、导通时长、或断开时长中任一者，从而达到调整负载功率的效果。
在实施例中，所述开关电路322可包括一切换开关，切换开关可举例为金属-氧化物-半导体场效应晶体管(Metal-oxide-semiconductor Field-effect Transistor,MOSFET)、双极结型晶体管(Bipolar Junction Transistor,BJT)、三极管等。
更进一步地，还可以将功率转换电路也划分为驱动模块的一部分，请参阅图16，显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图，如图所示，所述驱动模 块包括驱动控制电路321、开关电路322、以及功率转换电路323。其中功率转换电路323具有第一接脚Pi_321、第一输出端Pi_322、以及第二输出端Pi_323，并通过其第一接脚Pi_321接受外部供电信号Vin(直流电信号)进行能量转换，以在第一输出端Pi_322和第二输出端Pi_323上输出负载供电信号Vout。所述功率转换电路323耦接于开关电路322。所述开关电路322受驱动控制电路321控制。
其中，所述功率转换电路323包括电感L323_1、续流二极管D323_1、以及电容C323_1。电感L323_1的一端与第二输出端Pi_323相连，另一端耦接于开关电路322的第一端。电容C323_1耦接于第一输出端Pi_322和第二输出端Pi_323之间，以稳定第一输出端Pi_322和第二输出端Pi_323之间的电压差，续流二极管D323_1的阴极耦接第一输出端Pi_322，阳极耦接开关电路322的第一端。开关电路322包括切换开关Q5，其具有第一端、第二端、及控制端，并以切换开关Q5的第一端作为开关电路322的第一端耦接于功率转换电路323的电感L323_1的另一端，切换开关Q5的第二端经一采样电阻Rcs_1连接电源地GND，以及切换开关Q5的控制端与驱动控制电路321的输出引脚GT耦接。需要说明的是，切换开关Q5的第二端与电源地GND之间配置的采样电阻Rcs_1用以构成一电流检测电路，将流过切换开关Q5的电流转换成电压值以形成反馈信号Vfb。当切换开关Q5导通时，电流检测电路上的反馈信号Vfb即可被采集并经负载反馈端Pi_320传至驱动控制电路321。
驱动控制电路321根据温度采样信号Vtem和反馈信号Vfb来决定切换开关Q5的导通及断开时机。当驱动控制电路321控制切换开关Q5导通时，外部供电信号Vin经第一接脚Pi_321流入，并经电容C323_1以及第一输出端Pi_322到第二输出端Pi_323、电感L323_1后由切换开关Q5流出。此时，电容C323_1及电感L323_1进行储能。当驱动控制电路321控制切换开关Q5断开时，电感L323_1及电容C323_1释放所储存的能量，电流经续流二极管D323_1续流到第一输出端Pi_322，从而在第一输出端Pi_322和第二输出端Pi_323输出负载供电信号Vout。需要说明的是，为了防止驱动模块空载作业，在一些实施例中，在第一输出端Pi_322和第二输出端Pi_323之间还串接有电阻R323_1，由于电阻R323_1可视实际应用情况增加或省略(非必要组件)，故图中以虚线表示之。
以下结合图16说明驱动模块如何根据温度采样信号执行降低向负载输出功率的操作的。需要提前说明的是，为了便于说明，在图16示出了温度采样装置31，并且为了限流以及能够便于调节驱动模块向负载输出功率的水平，温度采样装置31的输出端Pi_310与驱动控制电路321的反馈引脚CS之间还耦接一电阻R31_1，以及驱动控制电路321的反馈引脚CS与 负载反馈端Pi_320之间耦接一电阻R32_1(后图17至19中为了仅描述驱动模块的电路架构而不再示出，但在实际连接中，温度采样装置31的输出端Pi_310与驱动控制电路321的反馈引脚CS之间是耦接有电阻R31_1的，以及驱动控制电路321的反馈引脚CS与负载反馈端Pi_320之间是耦接有电阻R32_1的)。驱动控制电路321的工作原理为基于驱动控制电路321内部运算放大器的参考端设置的参考电压与反馈引脚CS上获取的电压信号进行对比，根据对比结果调整开关电路322的导通和断开时机，从而最终使得反馈引脚CS上获取的电压信号与内部设置的参考电压相等。故而，在分析中，以反馈引脚CS上获取的电压信号(Vcs)被稳定在参考电压上来看，根据驱动控制电路321内部运算放大器的“虚短”特性，则流过电阻R31_1的电流与流过电阻R32_1的电流相等，也即，等式
Figure PCTCN2020135541-appb-000004
其中Vfb＝Ics*Rcs_1成立，所以，在温度采样信号Vtem较大时(也即，待保护电路的温度过高时)，驱动控制电路321通过输出引脚GT输出的控制信号调整切换开关Q5的导通及断开时机，从而使得经切换开关Q5流入电阻Rcs_1电流Ics减小，也即使得流过负载的电流减小，从而降低了向负载输出功率。其中，电阻R31_1和电阻R32_1作为上述分析中等式的固定系数，其相关于驱动模块调节向负载输出功率的水平，换言之，电阻R31_1和电阻R32_1的阻值相关于温度保护的性能。以温度采样信号Vtem为对应于温度采样装置感受LED模块温度而所输出的固定数值为例(如LED模块工作在80℃，温度采样信号Vtem为对应于80℃温度采样装置所输出的数值)，则R32_1/R31_1的值越大，驱动模块将向负载输出的功率降低到越小的数值，而在R32_1/R31_1的值较大时，则驱动模块将向负载输出的功率降低到的数值越高，本领域技术人员在实际应用中可根据实际情况想要达到的温度保护性能对电阻R31_1和电阻R32_1的参数进行选择。
亦可以解释为，驱动控制电路321的工作原理为基于驱动控制电路321内部运算放大器的参考端设置的参考电压Vref与反馈引脚CS上获取的电压信号Vcs进行对比，当Vcs大于Vref时，驱动控制电路321通过引脚GT输出的控制信号降低切换开关Q5的占空比，使得流过负载的电流减小，从而降低了负载功率；当Vcs小于Vref时，驱动控制电路321通过引脚GT输出的控制信号增加切换开关Q5的占空比，使得流过负载的电流增大，从而提高负载功率。
本实施中驱动模块既可以工作在恒流模式，通过调整输出电流调整输出功率，也可以工作在恒压模块，通过调整输出电压调整输出功率。
请参阅图17，显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图，如图所示，所述驱动模块包括驱动控制电路321、开关电路322、以及功率转换电路323。其中功率转换电路323具有第一接脚Pi_321、第一输出端Pi_322、以及第二输出端Pi_323，并通过其第一接脚Pi_321接受外部供电信号Vin(直流电信号)进行能量转换，以在第一输出端Pi_322和第二输出端Pi_323上输出负载供电信号Vout。所述功率转换电路323耦接于开关电路322。所述开关电路322受驱动控制电路321控制。
其中，所述功率转换电路323包括电感L323_2、续流二极管D323_2、以及电容C323_2。电感L323_2的一端与第一接脚Pi_321相连，另一端耦接于开关电路322的第一端。电容C323_2耦接于第一输出端Pi_322和第二输出端Pi_323之间，以稳定第一输出端Pi_322和第二输出端Pi_323之间的电压差，续流二极管D323_2的阴极耦接第一输出端Pi_322，阳极耦接开关电路322的第一端。开关电路322包括切换开关Q6，其具有第一端、第二端、及控制端，并以切换开关Q6的第一端作为开关电路322的第一端耦接于功率转换电路323的电感L323_2的另一端，切换开关Q6的第二端与第二输出端Pi_323相耦接，并且还经一采样电阻Rcs_2连接电源地GND，切换开关Q6的控制端与驱动控制电路321的输出引脚GT耦接。需要说明的是，切换开关Q6的第二端与电源地GND之间配置的采样电阻Rcs_2用以构成一电流检测电路，将流过切换开关Q6的电流转换成电压值以形成反馈信号Vfb。当切换开关Q6导通时，电流检测电路上的反馈信号Vfb即可被采集并经负载反馈端Pi_320传至驱动控制电路321。图示中开关电路322仅以表示连接关系，并非开关电路322包含在功率转换电路323。
驱动控制电路321根据温度采样信号Vtem和反馈信号Vfb来决定切换开关Q6的导通及断开时机。当驱动控制电路321控制切换开关Q6导通时，外部供电信号Vin由第一接脚Pi_321流入，并经电感L323_2、切换开关Q6、采样电阻Rcs_2流出至电源地GND。此时，流经电感L323_2的电流随时间增加，电感L323_2处于储能状态，同时，电容C323_2处于释能状态。当切换开关Q6截止时，电感2203b处于释能状态，电感L323_2的电流随时间减少。电感L323_2的电流经续流二极管D323_2续流流向电容C323_2以及第一输出端Pi_322。从而在第一输出端Pi_322和第二输出端Pi_323输出负载供电信号Vout。需要说明的是，为了防止负载工作在空载时，稳定输出电压。在一些实施例中，在第一输出端Pi_322和第二输出端Pi_323之间还串接有电阻R323_2，由于电阻R323_2可视实际应用情况增加或省略(非必要组件)，故图中以虚线表示之。
请参阅图18，显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图，如图所示，所述驱动模块包括驱动控制电路321、开关电路322、以及功率转换电路323。其中功率转换电路323具有第一接脚Pi_321、第一输出端Pi_322、以及第二输出端Pi_323，并通过其第一接脚Pi_321接受外部供电信号Vin(直流电信号)进行能量转换，以在第一输出端Pi_322和第二输出端Pi_323上输出负载供电信号Vout。所述功率转换电路323耦接于开关电路322。所述开关电路322受驱动控制电路321控制。
其中，所述功率转换电路323包括电感L323_3、续流二极管D323_3、以及电容C323_3。电感L323_3的一端与第一输出端Pi_322相连，另一端耦接于开关电路322的第二端。电容C323_3耦接于第一输出端Pi_322和第二输出端Pi_323之间，以稳定第一输出端Pi_322和第二输出端Pi_323之间的电压差，续流二极管D323_3的阳极耦接第一输出端Pi_322并接电源地GND，阴极耦接开关电路322的第二端。所述开关电路322包括切换开关Q7，其具有第一端、第二端、及控制端，以切换开关Q7的第一端作为开关电路322的第一端与第一接脚Pi_321耦接，并且切换开关Q7的第一端还经负载反馈端Pi_320耦接驱动控制电路321的反馈引脚CS，以将流过切换开关Q7的电流以反馈信号Vfb的形式反馈给驱动控制电路321，切换开关Q7的第二端作为开关电路322的第二端与功率转换电路323耦接，切换开关Q7的控制端与驱动控制电路321的输出引脚GT耦接。
驱动控制电路321根据温度采样信号Vtem和反馈信号Vfb来决定切换开关Q7的导通及断开时机。当切换开关Q7导通时，外部供电信号Vin由切换开关Q7的第一端流入，经切换开关Q7、电感L323_3并经过电容C323_3及第一输出端Pi_322流入第二输出端Pi_323。此时，流经电感L323_3的电流以及电容C323_3的电压随时间增加，电感L323_3及电容C323_3处于储能状态。当切换开关Q7截止时，电感L323_3处于释能状态，电感L323_3的电流随时间减少。此时，电感L323_3的电流经第一输出端Pi_322、第二输出端Pi_323、续流二极管D323_3再回到电感L323_3而形成续流。从而在第一输出端Pi_322和第二输出端Pi_323输出负载供电信号Vout。需要说明的是，为了防止驱动模块空载作业，在一些实施例中，在第一输出端Pi_322和第二输出端Pi_323之间还串接有电阻R323_3，由于电阻R323_3可视实际应用情况增加或省略(非必要组件)，故图中以虚线表示之。
请参阅图19，显示为本申请温度保护装置在又一实施例中的驱动模块的电路架构示意图，如图所示，所述驱动模块包括驱动控制电路321、开关电路322、以及功率转换电路323。其中功率转换电路323具有第一接脚Pi_321、第一输出端Pi_322、以及第二输出端Pi_323，并 通过其第一接脚Pi_321接受外部供电信号Vin(直流电信号)进行能量转换，以在第一输出端Pi_322和第二输出端Pi_323上输出负载供电信号Vout。所述功率转换电路323耦接于开关电路322。所述开关电路322受驱动控制电路321控制。
其中，所述功率转换电路323包括电感L323_4、续流二极管D323_4、以及电容C323_4。电感L323_4的一端与第一接脚Pi_321相连，另一端耦接于开关电路322的第一端。电容C323_4耦接于第一输出端Pi_322和第二输出端Pi_323之间，以稳定第一输出端Pi_322和第二输出端Pi_323之间的电压差，续流二极管2242_2的阴极耦接第二输出端Pi_323，阳极耦接开关电路322的第一端。所述开关电路322包括切换开关Q8，其具有第一端、第二端、及控制端，并以切换开关Q8的第一端作为开关电路322的第一端耦接于功率转换电路323，切换开关Q8的第二端经一采样电阻Rcs_3连接电源地GND，以及切换开关Q8的控制端与驱动控制电路321的输出引脚GT耦接。需要说明的是，切换开关Q8的第二端与电源地GND之间配置的采样电阻Rcs_3用以构成一电流检测电路，将流过切换开关Q8的电流转换成电压值以形成反馈信号Vfb。当切换开关Q8导通时，电流检测电路上的反馈信号Vfb即可被采集并经负载反馈端Pi_320传至驱动控制电路321。
驱动控制电路321根据温度采样信号Vtem和反馈信号Vfb来决定切换开关Q8的导通及断开时机。当切换开关Q8导通时，外部供电信号Vin由第一接脚Pi_321流入，并流经电感L323_4、切换开关Q8、采样电阻Rcs_3后流入第二接脚221。此时，流经电感L323_4的电流随时间增加，电感L323_4处于储能状态；电容C323_4的电压随时间减少，电容C323_4处于释能状态，以维持第一输出端Pi_322及第二输出端Pi_323之间的电压。当功率开关Q8截止时，电感L323_4处于释能状态，电感L323_4的电流随时间减少。此时，电感L323_4的电流经续流二极管D323_4、第二输出端Pi_323、及第一输出端Pi_322再回到电感L323_4而形成续流。此时，电容C323_4处于储能状态，电容C323_4的电压随时间增加。从而在第一输出端Pi_322和第二输出端Pi_323输出负载供电信号Vout。需要说明的是，为了防止驱动模块空载作业，在一些实施例中，在第一输出端Pi_322和第二输出端Pi_323之间还串接有电阻R323_4，由于电阻R323_4可视实际应用情况增加或省略(非必要组件)，故图中以虚线表示之。
图17至图19中的驱动模块如何根据温度采样信号Vtem执行降低向负载输出功率的操作的工作原理与图16类似，在此不做赘述。
在一些实际电路中，在负载通电瞬间或遭受到雷击时，开关电路的回路上容易产生大电 流(可能达到10A以上)而使电流检测电路与驱动控制电路损毁。上述至少一示例所提及的功率转换电路可更包含一钳位组件，其可与电流检测电路连接，用以在流经电流检测电路的电流或电流检测电路两端的电压差超过一预设值时，对电流检测电路的回路进行钳位操作，藉以限制流经电流检测电路的电流。在一些具体实施例中，所述钳位组件可例如是多个二极管，所述多个二极管相互串联，以形成一二极管串，所述二极管串与电流检测电路相互并联。在此配置底下，当开关电路的回路上产生大电流时，并联于电流检测电路的二极管串会快速导通，使得电流检测电路的两端可被限制在特定电平上。举例来说，若二极管串是由5个二极管所组成，由于单一二极管的导通电压约为0.7V，因此二极管串可将电流检测电路的跨压钳位在3.5V左右。
图13至图19所描述的实施例中任一所对应的温度保护单元32仅仅是一种示例，并不是对温度保护单元32的限制。在一些实施例中，温度保护单元32包括散热模块，散热模块设置在待保护电路处，并与温度采样装置31相耦接，从而散热模块根据接收的温度采样信号Vtem执行散热操作。所述散热模块可例如包括风扇，散热模块根据温度采样信号Vtem控制风扇以固定转速或对应于温度采样信号Vtem的大小的转速而转动，从而对待保护电路进行散热。
需要说明的是，温度保护装置30可设置于一LED照明系统中，也即待保护电路为LED模块，所述照明系统可包括大功率的照明系统(如向LED模块输出的功率超过30W)、具有调光功能的照明系统等。在所述照明系统为大功率的照明系统时，温度保护单元32可采用图14至图19任一实施例中的温度保护单元32；在所述照明系统为具有调光功能的照明系统时，温度保护单元32可包括调光模块，调光模块耦接于所述温度采样装置31，用于根据温度采样信号Vtem输出用于降低所述LED照明系统中LED负载电路的亮度的调光信号。
以上各实施例中提出的温度保护装置通过热敏电阻来感知待保护电路的环境温度，成本低廉，并且通过降低输出功率的方式达到为待保护电路降温的效果，节能且安全；另外温度保护装置中的温度采样装置可以直接与温度保护单元中的驱动控制电路本身具有的引脚相耦接，既不需要对温度保护单元本身的电路进行更改，也不需要额外设计相适配的电路即可实现温度保护功能，通用性强。
在可能的实施方式中，本申请还提出一种LED照明系统，请参阅图20，显示为本申请LED照明系统在一实施例中的电路方块示意图，如图所示，所述LED照明系统包括如前图1至图12C实施例中任一实施例所述的温度采样装置20、开关电源40、以及LED负载电路10。 所述温度采样装置20的电路架构以及工作原理请参阅针对图1至图12C的说明，在此不做赘述，所述开关电源40耦接于LED负载电路10，用于将外部交流电源所提供的交流信号AC转换成LED负载电路10的供电信号，开关电源40还耦接于温度采样装置20，从而开关电源40可根据温度采样装置20所提供的温度采样信号Vtem执行降低向LED负载电路输出功率的操作。其中，所述照明系统可包括大功率的照明系统(如向LED模块输出的功率超过30W)、具有调光功能的照明系统等，本申请对此并不做限定。
在其他实施例中，开关电源40可被称为电源模块，LED负载电路10可被称为LED模块，温度采样装置20可被称为温度保护电路，温度采样信号Vtem可被称为温度保护信号Vtem。LED照明系统包含温度保护电路20、电源模块40和LED模块10。电源模块40电性连接至外部电源，用以接收机外部电力信号AC并生成驱动信号。LED模块10电性连接至电源模块40，用以接收所述驱动信号而点亮。温度保护电路20电性连接至电源模块40，用以采集电源模块120或者LED模块10的工作温度并根据采集的温度生成温度保护信号Vtem。电源模块40接收温度保护信号Vtem，并根据温度保护信号Vtem调整输出功率，其中，当所述工作温度高于设定阈值时，电源模块40降低输出功率，以减少发热。
通过本实施例的配置方式，可将LED灯的工作温度控制在额定温度内，保证LED灯正常运行，延长LED灯的使用寿命。
请参阅图21，显示为本申请LED照明系统在一实施例中的开关电源的电路方块示意图，如图所示，所述开关电源40包括整流模块41、滤波模块42、以及驱动模块43。所述整流模块41藉由其第一整流输入端Pi_411和第二整流输入端Pi_412接收外部交流电源所输出的交流信号AC，并对该交流信号AC进行整流，然后由第一整流输出端Pi_413和第二整流输出端Pi_414输出整流后信号。所述滤波模块42耦接于整流模块41，用于接收第一整流输出端Pi_413和第二整流输出端Pi_414输出的整流后信号并对整流后信号滤波，而在第一滤波输出端Pi_421和第二滤波输出端Pi_422输出供电信号Vdc。驱动模块43耦接于滤波模块42，用于将滤波后的整流信号进行能量转换以向LED负载供电，并且，驱动模块43还耦接于温度采样装置20以根据温度采样信号Vtem执行降低向LED负载电路输出功率的操作。其中，第二整流输入端Pi_412、第二整流输出端Pi_414、以及第二滤波输出端Pi_422作为参考低电位端，接入电源地GND或基准地SGND。
请参阅图22，显示为本申请LED照明系统在一实施例中的整流模块的电路架构示意图，如图所示，所述整流模块41为桥式整流电路，所述整流模块24具有第一整流输入端Pi_411、 第二整流输入端Pi_412、第一整流输出端Pi_413、以及第二整流输出端Pi_414，整流模块24还包括第一整流二极管D41_1、第二整流二极管D41_2、第三整流二极管D41_3及第四整流二极管D41_4，用以对所接收的交流信号AC进行全波整流。第一整流二极管D41_1的阳极耦接第二整流输出端Pi_414，阴极耦接第二整流输入端Pi_412。第二整流二极管D41_2的阳极耦接第二整流输出端Pi_414，阴极耦接第一整流输入端Pi_411。第三整流二极管D41_3的阳极耦接第二整流输入端Pi_412，阴极耦接第一整流输出端Pi_413。第四整流二极管D41_4的阳极耦接第一整流输入端Pi_411，阴极耦接第一整流输出端Pi_413。
当第一整流输入端Pi_411和第二整流输入端Pi_412接收外部的交流信号AC时，整流模块41的操作描述如下。当交流信号AC处于正半波时，其依序经第一整流输入端Pi_411、第四整流二极管D41_4和第一整流输出端Pi_413后流入，并依序经第二整流输出端Pi_414、第一整流二极管D41_1和第二整流输入端Pi_412后流出。当交流信号AC处于负半波时，交流信号依序经第二整流输入端Pi_412、第三整流二极管D41_3和第一整流输出端Pi_413后流入，并依序经第二整流输出端Pi_414、第二整流二极管D41_2和第一整流输入端Pi_411后流出。因此，不论交流信号AC处于正半波或负半波，整流模块41的整流后信号的正极均位于第一整流输出端Pi_413，负极均位于第二整流输出端Pi_414。依据上述操作说明，整流模块41输出的整流后信号为全波整流信号。
整流模块41的结构并不以此为限，整流模块41也可以是其他种类的全波整流电路或半波整流电路，而不影响本申请方案欲达到的功能。
请参阅图23，显示为本申请LED照明系统在一实施例中的滤波模块的电路架构示意图，如图所示，所述滤波模块42包括一电容C42_1，电容C42_1的一端耦接第一整流输出端Pi_413及第一滤波输出端Pi_421，另一端耦接第二整流输出端Pi_414及第二滤波输出端Pi_422，以对由第一整流输出端Pi_413及第二整流输出端Pi_414输出的整流后信号进行低通滤波，以滤除整流后信号中的高频成分而形成滤波后信号并由第一滤波输出端Pi_421及第二滤波输出端Pi_422输出，作为供电信号Vdc。
请参阅图24，显示为本申请LED照明系统在另一实施例中的滤波模块的电路架构示意图，如图所示，所述滤波模块42包括一π型滤波电路，所述π型滤波电路包括一电容器C42_2、一电感器L42_1及一电容器C42_3。一个π型滤波电路在形状或结构上看上去像符号“π”。电容器C42_2的一端连接至第一整流输出端Pi_413并经电感器L42_1耦接于第一滤波输出端Pi_421，电容器C42_2的另一端连接第二整流输出端Pi_414和第二滤波输出端Pi_422。电感 器L42_1耦接于第一整流输出端Pi_413和第一滤波输出端Pi_421之间。电容器C42_3的一端连接至第一滤波输出端Pi_421并经电感器L42_1耦接至第一整流输出端Pi_413，而另一端则连接至第二整流输出端Pi_414和第二滤波输出端Pi_422。
如在整流输出端Pi_413、Pi_414以及滤波输出端Pi_421、Pi_422之间所见，图24中所示的滤波模块与图23中的滤波模块相比而言，另外还包括一电感器L42_1和一电容器C42_3，电感器L42_1和一电容器C42_3可实现与电容器C42_1类似的低通滤波功能。因此，图24中所示的滤波单元与图23中的滤波单元相比，能够更好地滤除高频信号，以输出波形更平滑的滤波后信号。
图24所示实施例中的电感器L42_1的感值较佳为选自10nH-10mH的范围。图23中的电容C42_1，以及图24中的电容器C42_2、C42_3的容值较佳为选自100pF-1uF的范围。
滤波模块42的结构并不以此为限，滤波模块42也可以是其他种类的如LC型滤波电路、RC型滤波电路、LCπ型滤波电路、RCπ型滤波电路等，而不影响本申请方案欲达到的功能。
在一些实施例中，驱动模块43可以采用如前图14至图19实施例中任一实施例所述的驱动装置，其中，图14至图19中驱动装置所接收的外部供电信号Vin为滤波模块42所输出的供电信号Vdc，其输出的负载供电信号Vout作为LED负载电路的供电信号，其电路架构以及工作原理请参阅针对图14至图19的说明，在此不做赘述。
请参阅图25，显示为本申请LED照明系统在一实施例中的LED负载电路的架构示意图，如图所示，所述LED负载电路10的正端耦接驱动模块的第一输出端Pi_322，负端耦接驱动模块的第二输出端Pi_323。LED负载电路10包含至少一个LED单元100a，LED单元100a为两个以上时彼此并联。每一个LED单元的正端耦接LED负载电路10的正端，以耦接第一输出端Pi_322；每一个LED单元的负端耦接LED负载电路10的负端，以耦接第二输出端Pi_323。LED单元100a包含至少一个LED组件1000a，即LED灯的光源。当LED组件1000a为多个时，LED组件1000a串联成一串，第一个LED组件1000a的正端耦接所属LED单元100a的正端，第一个LED组件1000a的负端耦接下一个(第二个)LED组件1000a。而最后一个LED组件1000a的正端耦接前一个LED组件1000a的负端，最后一个LED组件1000a的负端耦接所属LED单元100a的负端。
请参见图26，显示为本申请LED照明系统在另一实施例中的LED负载电路的架构示意图，如图所示，LED负载电路10的正端耦接驱动模块的第一输出端Pi_322，负端耦接驱动模块的第二输出端Pi_323。本实施例的LED负载电路10包含至少二个LED单元100b，而 且每一个LED单元100b的正端耦接LED负载电路10的正端，以及负端耦接LED负载电路10的负端。LED单元100b包含至少二个LED组件1000b，在所属的LED单元100b内的LED组件1000b的连接方式如同图25所描述般，LED组件1000b的负极与下一个LED组件1000b的正极耦接，而第一个LED组件1000b的正极耦接所属LED单元100b的正极，以及最后一个LED组件1000b的负极耦接所属LED单元100b的负极。再者，本实施例中的LED单元100b之间也彼此连接。每一个LED单元100b的第n个LED组件1000b的正极彼此连接，负极也彼此连接。因此，本实施例的LED负载电路10的LED组件间的连接为网状连接。实际应用上，LED单元100b所包含的LED组件1000b的数量较佳为15-25个，更佳为18-22个。
另外，为了防止LED负载电路在刚上电时由于电压过冲而损坏或不能正常启动，在一些实施例中，所述LED照明系统还包括启动保护电路44，请参阅图27并结合图1至图12C，图27显示为本申请LED照明系统在一实施例中的启动保护电路的电路方块示意图，如图所示，所述启动保护电路44耦接于温度采样装置20的温度检测单元21的检测端Pi_210与提供第一参考信号的参考端Pi_222之间，用于在LED照明系统上电启动时，利用所述温度采样信号Vtem对所述LED负载电路进行启动保护。
请参阅图28，显示为本申请LED照明系统在一实施例中的启动保护电路的电路架构示意图，为了便于说明启动保护电路提供启动保护的原理，图中以图2所示的温度检测单元21且热敏电阻R21_2为NTC为例，如图所示，启动保护电路44包括电容C44_1，电容C44_1的一端耦接于温度检测单元21的检测端Pi_210，另一端耦接于参考端Pi_222(图28中以参考端Pi_222接入电源地GND示出)。在照明系统上电启动时，由于电容C44_1上的电压不能突变，所以在刚上电阶段，电源Vcc对电容C44_1充电，电容C44_1上的电压从零开始缓慢升高，也即检测信号Vdec在启动阶段是很小的。此时，可等效于热敏电阻R21_2的阻值很小来看，根据上述针对图5所描述的信号处理单元22的工作原理，可知，热敏电阻R21_2的阻值越小，则信号处理单元22输出的温度采样信号Vtem越大。故而，在启动阶段，温度采样信号Vtem很大，从而使得驱动模块向LED负载电路输出的功率很小，LED负载电路的LED模块很暗，随着电容C44_1上的电压的缓慢升高，温度采样信号Vtem则缓慢降低，驱动模块根据温度采样信号Vtem缓慢增大向LED负载电路输出的功率，从而使得LED负载电路的LED模块缓慢的由暗至明，LED负载电路完成其软启动过程。
以上各实施例中提出的LED照明系统通过热敏电阻来感知LED负载电路的环境温度，并且通过降低输出功率的方式达到为LED负载电路降温的效果，成本低廉，节能且安全；另 外温度采样装置可以直接与现有的LED照明系统中的开关电源本身具有的引脚相耦接，既不需要对LED照明系统中开关电源本身的电路进行更改，也不需要额外设计相适配的电路或芯片即可实现温度保护功能，通用性强。
在可能的实施方式中，本申请还提出一种温度采集的方法，所述温度采集的方法应用于温度采样装置，其中，所述温度采样装置中包含随环境温度变化而改变阻值的电路。请参阅图29，显示为本申请温度采集的方法在一实施例中的流程图，如图所示，所述温度采集的方法包括步骤S20和步骤S21。
在步骤S20中，限制所述温度采样装置中受所述阻值变化影响的检测信号。
其中，温度采样装置包括温度检测单元和信号处理单元，其中，温度检测单元的阻值会受待保护电路的环境变化而改变，检测信号为由温度检测单元的输出的受其阻值变化影响的电信号，温度检测单元电路结构和检测信号受其阻值变化影响详细工作过程请参阅针对图2和图3的描述，在此不再赘述。
信号处理单元包括放大模块和反馈模块，反馈模块限制所述温度采样装置中受所述阻止变化影响的检测信号。请参阅针对图4至图7，其中各实施例说明了反馈模块221限制检测信号Vdec的详细过程，在此不再重述。基于图11-25及对应描述，反馈模块221基于信号处理单元22输出的温度采样信号Vtem而形成的反馈信号FB来限制检测信号Vdec的变化。
在步骤21中，输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的。
信号处理单元包括放大模块和反馈模块，放大模块输出与所述阻止变化对应的温度采样信号。请参阅针对图4至图12C，其中各实施例说明了放大模块222输出温度采样信号Vtem的详细过程，在此不再重述。基于图4-12C及对应描述，放大模块222基于经限制检测信号Vdec，对其输入端Pi_221所接收的信号进行放大处理，从而输出与温度检测单元21的阻值变化对应的温度采样信号Vtem。
在可能的在可能的实施方式中，本申请还提出一种LED灯的温度保护方法，所述温度保护的方法应用于温度保护装置。请参阅图30，显示为本申请LED灯的温度保护方法在一实施例中的流程图，如图所示，所述LED灯的温度保护方法包括步骤S30、步骤S31、以及步骤S32。
在步骤S30中，限制所述温度采样装置中受所述阻值变化影响的检测信号。
温度保护装置包括温度采样装置和温度保护单元，其中，温度采样装置包括温度检测单 元和信号处理单元，温度检测单元的阻值会受待保护电路的环境变化而改变，检测信号为由温度检测单元的输出的受其阻值变化影响的电信号，温度检测单元电路结构和检测信号受其阻值变化影响详细工作过程请参阅针对图2和图3的描述，在此不再赘述。
信号处理单元包括放大模块和反馈模块，反馈模块限制所述温度采样装置中受所述阻止变化影响的检测信号。请参阅针对图4至图7，其中各实施例说明了反馈模块221限制检测信号Vdec的详细过程，在此不再重述。基于图4至图7及对应描述，反馈模块221基于信号处理单元22输出的温度采样信号Vtem而形成的反馈信号FB来限制检测信号Vdec的变化。
在步骤31中，输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的。
信号处理单元包括放大模块和反馈模块，放大模块输出与所述阻止变化对应的温度采样信号。请参阅针对图4至图12C，其中各实施例说明了放大模块222输出温度采样信号Vtem的详细过程，在此不再重述。基于图4-12C及对应描述，放大模块222基于经限制检测信号Vdec，对其输入端Pi_221所接收的信号进行放大处理，从而输出与温度检测单元21的阻值变化对应的温度采样信号Vtem。
在步骤S32中，基于所述温度采样信号执行对LED灯的温度保护操作。
温度保护单元耦接于温度采样装置以接收于温度采样装置输出的温度采样信号，并基于温度采样信号执行对LED灯的温度保护操作。
在一实施例中，所述温度保护单元包括LED灯中的开关电源，所述开关电源基于所述温度采样信号降低所输出的供电功率。请参阅针对图14至图24，其中各实施例说明了开关电源40基于所述温度采样信号Vtem降低所输出的功率的详细过程，在此不再重述。基于图14至24及对应描述，开关电源40中的驱动模块用于基于温度采样信号Vtem降低所输出的功率，驱动模块中的驱动控制电路321根据温度采样信号Vtem和反馈信号Vfb来决定开关电路322中的切换开关的导通及断开，在温度采样信号Vtem较大时，驱动控制电路321通过控制开关电路322的导通和断开时机来达到降低流过负载电流Ics的目的，从而降低了向负载输出的功率，也即开关电源40的供电功率。
在另一实施例中，LED灯为具有调光功能的LED灯，温度保护单元包括LED灯中的调光模块，调光模块基于所述温度采样信号调整所输出的调光信号，以在温度升高时降低LED灯的亮度。
在又一实施例中，所述温度保护单元包括一散热装置，所述散热装置设置在待保护电路 处，并与温度采样装置相耦接，从而散热装置根据接收的温度采样信号执行散热操作。所述散热装置可例如包括风扇，散热装置根据温度采样信号控制风扇以固定转速或对应于温度采样信号的大小的转速而转动，从而对待保护电路进行散热。
本申请提出的温度采样装置、温度保护装置及方法、以及照明系统通过热敏电阻来感知LED负载电路的环境温度，并且通过降低输出功率的方式达到为LED负载电路降温的效果，成本低廉，节能且安全；另外温度采样装置可以直接与现有的LED照明系统中的开关电源本身具有的引脚相耦接，既不需要对LED照明系统中开关电源本身的电路进行更改，也不需要额外设计相适配的电路或芯片即可实现温度保护功能，通用性强。
上述实施例仅例示性说明本申请的原理及其功效，而非用于限制本申请。任何熟悉此技术的人士皆可在不违背本申请的精神及范畴下，对上述实施例进行修饰或改变。因此，举凡所属技术领域中具有通常知识者在未脱离本申请所揭示的精神与技术思想下所完成的一切等效修饰或改变，仍应由本申请的权利要求所涵盖。

Claims (40)

  1. 一种温度采样装置，其特征在于，所述温度采样装置包括：
    具有检测端的温度检测单元，用于受待保护电路的环境温度变化而改变自身的阻值；
    信号处理单元，耦接于所述检测端，用于限制所述温度检测单元中受所述阻值变化影响的检测信号，以输出与所述阻值变化对应的温度采样信号；
    其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的；其中，所述温度采样信号用于向温度保护装置传输。
  2. 根据权利要求1所述的温度采样装置，其特征在于，所述阻值的变化与环境温度的变化之间具有单调性。
  3. 根据权利要求1所述的温度采样装置，其特征在于，所述温度采样信号在环境温度达到起始保护温度时予以输出。
  4. 根据权利要求1所述的温度采样装置，其特征在于，所述温度采样信号的变化与阻值的变化之间具有单调性。
  5. 根据权利要求1所述的温度采样装置，其特征在于，所述信号处理单元基于所述检测信号的变化而从第一状态转入第二状态；其中，在第二状态期间，所述信号处理单元产生所述温度采样信号。
  6. 根据权利要求1所述的温度采样装置，其特征在于，所述温度检测单元包括：串联的热敏电阻及分压电阻，所述检测端位于热敏电阻及分压电阻之间。
  7. 根据权利要求6所述的温度采样装置，其特征在于，所述热敏电阻包括随环境温度变化而阻值正向变化的可变电阻。
  8. 根据权利要求6所述的温度采样装置，其特征在于，所述热敏电阻包括随环境温度变化而阻值负向变化的可变电阻。
  9. 根据权利要求1所述的温度采样装置，其特征在于，所述信号处理单元包括：
    放大模块，其输入端耦接所述检测端，其参考端接入第一参考信号，以及其输出端输出所述温度采样信号；以及
    反馈模块，耦接于所述检测端和所述放大模块的输出端之间，用于将根据所述温度采样信号而形成的反馈信号反馈至所述检测端，以限制所述检测信号的变化；
    其中，所述放大模块基于经限制的检测信号，对所述输入端所接收的信号进行放大处理输出所述温度采样信号。
  10. 根据权利要求9所述的温度采样装置，其特征在于，所述反馈模块用于确定所述温度检测单元的阻值变化范围对应于预设的所述温度采样信号的信号量变化范围。
  11. 根据权利要9所述的温度采样装置，其特征在于，所述放大模块包括接入所述放大模块的参考端和输出端之间电路的三极管，其控制端耦接所述放大模块的输入端。
  12. 根据权利要求9所述的温度采样装置，其特征在于，所述放大模块包括至少两个级联的三极管，第一级三极管的控制端耦接所述检测端，最后一级三极管接入所述放大模块的参考端与输出端之间电路中。
  13. 根据权利要求9所述的温度采样装置，其特征在于，所述放大模块包括运算放大器，其两个输入端分别耦接所述放大模块的输入端和参考端，以及所述运算放大器的输出端耦接所述放大模块的输出端。
  14. 根据权利要求1所述的温度采样装置，其特征在于，还包括输出单元，耦接所述信号处理单元的输出端，以输出所述温度采样信号。
  15. 根据权利要求14所述的温度采样装置，其特征在于，所述输出单元包括：电压跟随模块，其输入端耦接所述信号处理单元的输出端，参考端接收第二参考信号，以及所述电压跟随模块的输出端输出所述温度采样信号。
  16. 根据权利要求15所述的温度采样装置，其特征在于，所述电压跟随模块包括：连接在所述电压跟随模块的输入端和参考端之间的三极管，所述三极管还连接所述电压跟随模块的输出端以输出所述温度采样信号。
  17. 根据权利要求1所述的温度采样装置，其特征在于，还包括滤波单元，耦接所述信号处理单元的输出端，用于进行信号滤波。
  18. 根据权利要求1所述的温度采样装置，其特征在于，所述待保护电路包括以下至少一种：开关电源、受热而降低/失去效能的电子部件、或LED负载电路。
  19. 一种温度保护装置，其特征在于，包括：
    如权利要求1-18中任一所述的温度采样装置，用于检测待保护电路的环境温度并输出温度采样信号；以及
    温度保护单元，耦接于所述温度采样装置以获得所述温度采样信号，为待保护电路提供与所述环境温度变化相应的温度保护操作。
  20. 根据权利要求19所述的温度保护装置，其特征在于，所述待保护电路包括：开关电源、受热而降低/失去效能的电子部件、或LED负载电路。
  21. 根据权利要求19所述的温度保护装置，其特征在于，所述温度保护单元包括负载的驱动模块，耦接于所述温度采样装置；所述温度保护操作包括：根据所述温度采样信号执行降低向负载输出功率的操作。
  22. 根据权利要求21所述的温度保护装置，其特征在于，所述驱动模块包括：带有反馈引脚的驱动控制电路，所述温度采样信号传输至所述反馈引脚。
  23. 根据权利要求21所述的温度保护装置，其特征在于，所述驱动模块包括：基于BUCK电路架构而构建的电路结构、基于BOOST电路架构而构建的电路结构、及基于BOOST-BUCK电路架构而构建的电路结构中的任一种。
  24. 根据权利要求21所述的温度保护装置，其特征在于，所述温度采样信号区别于所述驱动模块获取的反映负载供电的反馈信号。
  25. 根据权利要求22所述的温度保护装置，其特征在于，所述驱动模块还包括开关电路，所述驱动控制电路向开关电路输出的控制信号随所述温度采样信号的变化而变化。
  26. 根据权利要求19所述的温度保护装置，其特征在于，所述温度保护单元包括散热模块，其设置在所述待保护电路处，耦接于所述温度采样装置；所述散热模块根据所述温度采样信号执行散热操作。
  27. 根据权利要求19所述的温度保护装置，其特征在于，所述温度保护装置设置于一LED照明系统中。
  28. 根据权利要求27所述的温度保护装置，其特征在于，所述温度保护单元包括调光模块，耦接于所述温度采样装置；所述调光模块，用于根据所述温度采样信号输出用于降低所述LED照明系统中LED负载电路的亮度的调光信号。
  29. 根据权利要求27所述的温度保护装置，其特征在于，所述LED照明系统包括：输出功率高于30W的照明系统。
  30. 一种LED照明系统，其特征在于，包括：
    如权利要求1-18中任一所述的温度采样装置；
    LED负载电路，受直流供电驱动；
    开关电源，耦接于所述LED负载电路，用于将外部交流电源所提供的交流信号转换成所述LED负载电路的供电信号；
    其中，所述开关电源还耦接于所述温度采样装置，根据所述温度采样装置所提供的温度采样信号执行降低向LED负载电路输出功率的操作。
  31. 根据权利要求30所述的LED照明系统，其特征在于，所述开关电源包括：
    整流模块，用于将所述交流信号进行整流处理并输出整流信号；
    滤波模块，耦接于所述整流模块，用于将所述整流信号进行滤波后输出；
    驱动模块，耦接于所述滤波模块，用于将滤波后的整流信号进行能量转换以向所述LED负载供电；
    其中，所述驱动模块还耦接于所述温度采样装置，根据所述温度采样信号执行降低向LED负载电路输出功率的操作。
  32. 根据权利要求31所述的LED照明系统，其特征在于，所述驱动模块包括：带有反馈引脚的驱动控制电路，所述温度采样信号输至所述反馈引脚。
  33. 根据权利要求31所述的LED照明系统，其特征在于，所述驱动模块包括：基于BUCK电路架构而构建的电路结构、基于BOOST电路架构而构建的电路结构、及基于BOOST-BUCK电路架构而构建的电路结构中的任一种。
  34. 根据权利要求31所述的LED照明系统，其特征在于，所述温度采样信号区别于所述驱动模块获取的反映所述LED负载电路供电的反馈信号。
  35. 根据权利要求32所述的LED照明系统，其特征在于，所述驱动模块还包括开关电路，所述驱动控制电路向开关电路输出的控制信号随所述温度采样信号的变化而变化。
  36. 根据权利要求30所述的LED照明系统，其特征在于，还包括启动保护电路，耦接于所述温度采样装置中温度检测单元的检测端与提供第一参考信号的参考端之间，用于在LED照明系统上电启动时，根据所述温度采样信号对所述LED负载电路进行启动保护。
  37. 根据权利要求31所述的LED照明系统，其特征在于，所述LED照明系统包括：输出功率高于30W的照明系统。
  38. 一种温度采集的方法，其特征在于，应用于温度采样装置，其中，所述温度采样装置中包含随环境温度变化而改变阻值的电路，所述温度采集的方法包括：
    限制所述温度采样装置中受所述阻值变化影响的检测信号；
    输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的。
  39. 一种LED灯的温度保护方法，其特征在于，温度保护方法包括以下步骤：
    限制所述温度采样装置中受所述阻值变化影响的检测信号；
    输出与所述阻值变化对应的温度采样信号；其中，所述温度采样信号是在所述检测信号受到所述限制的情形下形成的；
    基于所述温度采样信号执行对LED灯的温度保护操作。
  40. 根据权利要求39中所述的LED灯的温度保护方法，其特征在于，所述基于所述温度采样信号执行对LED灯的温度保护操作的步骤包括以下至少一种：
    令所述LED灯中的开关电源基于所述温度采样信号降低所输出的供电功率；
    令所述LED灯中的调光模块基于所述温度采样信号调整所输出的调光信号，以在温度升高时降低LED灯的亮度；或者
    令设置在所述LED灯的待保护电路处的散热装置基于所述温度采样信号执行散热操作。
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