CN110381637B - Over-temperature protection circuit and LED lamp - Google Patents
Over-temperature protection circuit and LED lamp Download PDFInfo
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- CN110381637B CN110381637B CN201910663315.7A CN201910663315A CN110381637B CN 110381637 B CN110381637 B CN 110381637B CN 201910663315 A CN201910663315 A CN 201910663315A CN 110381637 B CN110381637 B CN 110381637B
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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]
- H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
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- 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]
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Abstract
The invention discloses an over-temperature protection circuit and an LED lamp, wherein the over-temperature protection circuit comprises: the control circuit module is used for adjusting the variation of the output current according to a predefined adjusting parameter in the over-temperature protection process, and the variation of the output current is controlled through the first control end; the temperature detection module is used for detecting the temperature variation of a circuit where the load is positioned and generating a control logic signal according to the temperature variation, and the control logic signal is output through the output end; the driving module is provided with a second control end, an input end and a controlled end, wherein the input end is electrically connected with the output end, the controlled end is electrically connected with the first control end, the second control end is electrically connected with the load circuit, the driving module controls the current curve slope of the load circuit through the second control end by means of the variation of the output current obtained by the controlled end and the control logic signal input by the input end, and the over-temperature protection circuit provided by the embodiment of the invention can be matched with the application condition to adjust the current curve slope of the load circuit.
Description
Technical Field
The invention relates to the technical field of circuits, in particular to an over-temperature protection circuit and an LED lamp.
Background
With the continuous development of the LED lamp, the requirements of the market on the reliability and quality of the LED lamp are higher. However, the cost of the LED lamp is continuously reduced, which provides a great challenge for the reliability and quality of the LED lamp; it is well known that two of the biggest influencing factors for the life of LED lamps are the life of the LED lamp beads and LED drivers, but the life of these devices is greatly affected by the ambient temperature. Therefore, how to prevent the temperature of the LED lamp beads and the LED driver from being too high is important.
At present, in the existing over-temperature protection circuit scheme, the curve of the current change of the LED is basically fixed inside, and can not be controlled in a programmable manner according to the application conditions of different lamps, so that the light output quality of the LED lamp can not be effectively optimized and improved, and meanwhile, the over-temperature dimming curve of the LED in the over-temperature triggering state can not be controlled.
Disclosure of Invention
The embodiment of the invention provides an over-temperature protection circuit and an LED lamp, which are used for solving the problem that the current change curve of a load circuit cannot be adjusted according to application conditions by the existing over-temperature protection circuit.
The embodiment of the invention adopts the following technical scheme:
In a first aspect, the present invention provides an over-temperature protection circuit comprising:
The control circuit module is configured to adjust the variation of the output current according to a predefined adjustment parameter in the process of over-temperature protection, and is provided with a first control end, and the variation of the output current is controlled through the first control end;
The temperature detection module is configured to detect the temperature variation of a circuit in which the load is positioned and generate a control logic signal according to the temperature variation, and is provided with an output end, and the control logic signal is output through the output end;
The driving module is provided with a second control end, an input end and a controlled end, wherein the input end is electrically connected with the output end, the controlled end is electrically connected with the first control end, the second control end is electrically connected with the load circuit,
The driving module controls the current change of the load circuit through the second control end by the variable quantity of the output current obtained by the controlled end and the control logic signal input by the input end so as to control the slope of the current curve of the load circuit.
Further, the driving module is provided with a MOS transistor, and the drain electrode of the MOS transistor is electrically connected with the load circuit;
The driving module controls the current change of the load circuit by driving the on-off time length of the MOS transistor and according to the proportion of the on-time length and the off-time length of the MOS transistor so as to control the slope of the current curve of the load circuit.
Further, the driving module includes: the device comprises a first comparator, a second comparator, a current mirror, a switching tube, a first capacitor, a first resistor, a sampling resistor, a logic control unit and a driving signal processing unit; wherein,
The first input end of the first comparator is electrically connected with a first reference voltage, the second input end of the first comparator, the drain electrode of the switching tube, one end of the first capacitor and one end of the current mirror are electrically connected with a first connection point, and the output end of the first comparator is electrically connected with the delay access end of the logic control unit;
The first input end of the second comparator is electrically connected with a second reference voltage, and the second input end of the second comparator, the other end of the current mirror and the control end of the control circuit module are electrically connected with a second connection point;
The first output end of the logic control unit is electrically connected with one end of the first resistor, the other end of the first resistor is electrically connected with the grid electrode of the switch tube, the second output end of the logic control unit is electrically connected with the driving signal processing unit, the driving signal processing unit is electrically connected with the grid electrode of the MOS transistor, the source electrode of the MOS transistor is electrically connected with one end of the sampling resistor, and the other end of the sampling resistor is grounded;
The logic control unit generates a driving signal according to the output signal of the first comparator and other control logic signals, and sends the driving signal to the driving signal processing unit, and the driving signal processing unit generates a driving instruction according to the driving signal so as to drive the MOS transistor to be turned on or turned off.
Further, the driving module includes: the constant current driving chip, the second resistor, the third resistor and the fourth resistor; wherein,
The 1 st pin of the constant current driving chip is electrically connected with the negative electrode of the voltage source, the 2 nd pin is electrically connected with one end of the fourth resistor to set a triggering starting point voltage value of the output open-circuit voltage, the 3 rd pin is electrically connected with the control end of the control circuit module to control the slope of a current curve of the load circuit by adjusting the variation of the output current according to a predefined adjusting parameter through the control circuit module under the over-temperature protection condition, the 4 th pin is electrically connected with the positive electrode of the voltage source, the 5th pin is electrically connected with the load circuit, the 6 th pin is electrically connected with one end of the second resistor so as to control the maximum peak current value of the current flowing through the external inductor, the 7 th pin is electrically connected with one end of the third resistor so as to control the temperature value of the starting point of the triggered over-temperature protection, and the other end of the second resistor, the other end of the third resistor and the other end of the fourth resistor are electrically connected with the positive electrode of the voltage source.
Further, the control circuit module includes: a capacitance-adjustable module and/or a resistance-adjustable module and/or a voltage-adjustable module; wherein,
One end of the capacitance adjustable module is electrically connected with the controlled end of the driving module, and the other end of the capacitance adjustable module is grounded;
One end of the resistance adjustable module is electrically connected with the controlled end of the driving module, and the other end of the resistance adjustable module is grounded;
One end of the voltage adjustable module is electrically connected with the controlled end of the driving module, and the other end of the voltage adjustable module is grounded.
Further, the resistance adjustable module includes: an adjustable resistance;
one end of the adjustable resistor is electrically connected with the controlled end of the driving module, and the other end of the adjustable resistor is grounded.
Further, the resistance adjustable module includes: and the second capacitor is connected with the adjustable resistor in parallel.
In a second aspect, the invention provides an LED lamp, which comprises the over-temperature protection circuit, a first inductor, a first diode and a load circuit;
One end of the load circuit is connected with the cathode of the first diode, the other end of the load circuit is connected with one end of the first inductor to form a fifth connection point, and the other end of the first inductor, the over-temperature protection circuit and the anode of the first diode are connected with a fourth connection point.
Further, the load circuit comprises at least one LED lamp and a fifth resistor, the at least one LED lamp is connected in series to form an LED lamp group, one end of the LED lamp group and one end of the fifth resistor are connected with the third connection point, and the other end of the LED lamp group and the other end of the fifth resistor are connected with the fifth connection point.
Further, the load circuit includes:
and one end of the third capacitor is electrically connected with the third connection point, and the other end of the third capacitor is electrically connected with the fifth connection point.
Further, the at least one LED lamp includes: bulb lamp, down lamp or panel lamp.
The above at least one technical scheme adopted by the embodiment of the invention can achieve the following beneficial effects:
The embodiment of the invention provides an over-temperature protection circuit which comprises a control circuit module, a temperature detection module and a driving module, wherein a first control end of the control circuit module is electrically connected with a controlled end of the driving module, an output end of the temperature detection module is electrically connected with an input end of the driving module, and a second control end of the driving module is electrically connected with a load circuit. The control circuit module is used for adjusting the variation of the output current according to a predefined regulation parameter in the over-temperature protection process, the temperature detection module is used for detecting the temperature variation of a circuit where the load is located and generating a control logic signal according to the temperature variation, and the driving module controls the slope of a current curve of the load circuit through the variation of the output current obtained by the controlled end and the control logic signal input by the input end and the second control end. Therefore, the over-temperature protection circuit provided by the embodiment of the invention can be matched with the application condition to adjust the slope of the current curve of the load circuit.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:
fig. 1 is a schematic structural diagram of an over-temperature protection circuit according to an embodiment of the present invention;
Fig. 2 is a schematic diagram of an over-temperature protection circuit connected to a load circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a portion with an over-temperature protection circuit according to an embodiment of the present invention;
Fig. 4 is a second schematic diagram of an over-temperature protection circuit connected to a load circuit according to an embodiment of the present invention;
fig. 5 is a graph showing a slope change of an LED lamp current curve with an over-temperature protection circuit according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1, an over-temperature protection circuit provided by an embodiment of the present invention includes: a control circuit module 10 for adjusting the variation of the output current according to a predefined adjustment parameter during the over-temperature protection process, a temperature detection module 20 for detecting the temperature variation of the circuit in which the load is located and generating a control logic signal according to the temperature variation, and a driving module 30. The circuit in which the load is located may refer to a circuit including a load, such as a circuit including an LED lamp. The connection and operation relationships among the control circuit module 10, the temperature detection module 20, and the driving module 30 are described below, and in detail, as shown in fig. 1 and 2, as follows:
The control circuit module 10 has a first control terminal 11 and controls the amount of change in the output current, which is obtained from a predefined regulation parameter, which may include a regulation voltage, a regulation resistance or a regulation capacitance, via the first control terminal 11. The specific implementation circuit of the control circuit module 10 may be a circuit for converting resistance values, a circuit for converting voltage values, a circuit for converting capacitance values, for example, a circuit including a sliding rheostat.
The temperature detection module 20 has an output terminal 21, and outputs a control logic signal through the output terminal 21, where the control logic signal is obtained according to the temperature variation of the circuit where the load is located. The specific implementation circuit of the temperature detection module 20 may be a circuit having a temperature detection device and capable of processing a temperature variation amount. For example, a circuit with a device or temperature sensor that is sensitive to ambient temperature.
The driving module 30 has a second control terminal 31, an input terminal 33 and a controlled terminal 32, the input terminal 33 is electrically connected with the output terminal 21, the controlled terminal 32 is electrically connected with the first control terminal 11, the second control terminal 31 is electrically connected with the load circuit 40, wherein the driving module 30 controls the slope of the current curve of the load circuit 40 through the second control terminal 31 by the variation of the output current obtained by the controlled terminal 32 and the control logic signal inputted by the input terminal 33. Specifically, the driving module 30 may have a MOS transistor Q101, where a drain D of the MOS transistor Q101 is electrically connected to the load circuit 40, and the driving module 30 drives a duration of turning on or off the MOS transistor Q101 by a variable amount of an output current obtained by the control terminal 32 and a control logic signal input by the input terminal 33, and controls a current change of the load circuit 40 according to a ratio of the duration of turning on to the duration of turning off the MOS transistor Q101, so as to control a slope of a current curve of the load circuit 40, as shown in fig. 5.
The embodiment of the invention provides an over-temperature protection circuit which comprises a control circuit module, a temperature detection module and a driving module, wherein a first control end of the control circuit module is electrically connected with a controlled end of the driving module, an output end of the temperature detection module is electrically connected with an input end of the driving module, and a second control end of the driving module is electrically connected with a load circuit. The control circuit module is used for adjusting the variation of the output current according to a predefined regulation parameter in the over-temperature protection process, the temperature detection module is used for detecting the temperature variation of a circuit where the load is located and generating a control logic signal according to the temperature variation, and the driving module controls the slope of a current curve of the load circuit through the variation of the output current obtained by the controlled end and the control logic signal input by the input end and the second control end. Therefore, the over-temperature protection circuit provided by the embodiment of the invention can be matched with the application condition to adjust the slope of the current curve of the load circuit.
Alternatively, the driving module 30 described in the above embodiment may be implemented by the following circuits:
As shown in connection with fig. 2 and 3, a first implementation circuit includes: the first comparator U201, the second comparator U202, the current mirror M201, the switch tube Q201, the first capacitor C201, the first resistor Rgate, the sampling resistor R1 (shown in FIG. 2), the logic control unit and the driving signal processing unit; as shown in fig. 3, a first input end of the first comparator U201 is electrically connected to a first reference voltage, a second input end of the first comparator U201, a drain D of the switching tube Q201, one end of the first capacitor C201, and one end of the current mirror M201 are electrically connected to the first connection point 1, and an output end of the first comparator U201 is electrically connected to a delay access end of the logic control unit; the first input end of the second comparator U202 is electrically connected with the second reference voltage, and the second input end of the second comparator U202, the other end of the current mirror M201 and the control end of the control circuit module 10 are electrically connected with the second connection point 2; the input end 33 of the logic control unit is electrically connected with the output end 21 of the temperature detection module, the first output end of the logic control unit is electrically connected with one end of a first resistor Rgate, the other end of the first resistor Rgate is electrically connected with the grid G of a switch tube Q201, the second output end of the logic control unit is electrically connected with a driving signal processing unit, the driving signal processing unit is electrically connected with the grid G of a MOS transistor Q101, the source S of the MOS transistor Q101 is electrically connected with one end of a sampling resistor R1, and the other end of the sampling resistor R1 is grounded;
The logic control unit generates a driving signal according to the output signal of the first comparator U201 and other control logic signals (such as control logic signals generated by the temperature detection module), and sends the driving signal to the driving signal processing unit, and the driving signal processing unit generates a driving instruction according to the driving signal to drive the MOS transistor Q101 to be turned on or turned off.
Assuming that the control circuit module 10 is a variable resistor, as shown in fig. 3, a specific working process of the control circuit module 10 and the driving module 30 in cooperation is as follows: when the first inductor L101 is charged and enters a follow current period, the switching tube Q201 is immediately conducted, the first capacitor C201 is short-circuited, and the first capacitor C201 is rapidly discharged to zero so as to prepare for the next charging period; when the freewheeling period of the first inductor L101 ends, that is, the first inductor L101 discharges to zero, the switching transistor Q201 is turned off, and at this stage the MOS transistor Q101 maintains an off state, the first capacitor C201 starts to charge, the variable resistor is adjusted according to the adjustment parameter predefined by the circuit, when the resistance value of the variable resistor is reduced, the currents at both ends of the current mirror M201 become larger, the rate of charging the first capacitor C201 connected to the current mirror M201 becomes faster, the charging duration decreases, otherwise, the resistance value of the variable resistor increases, the charging rate of the first capacitor C201 becomes faster, the charging duration increases, and when the charging voltage of the first capacitor C201 reaches the reference voltage of the first comparator U201, the output delay signal of the first comparator U201 is converted from low level to high level and is transmitted to a logic control unit, the logic control unit generates a drive signal according to the delay signal of the first comparator U201 and other logic signals (such as control logic signals generated by a temperature detection module) and sends the drive signal to a drive signal processing unit, the drive signal processing unit generates a drive instruction according to the drive signal so as to control the MOS transistor Q101 to enter a conducting state, at the moment, the first inductor L101 starts to be charged, the switching tube Q201 is in a continuous off state, and the output delay signal of the first comparator U201 is kept at the high level; when the first inductor L101 is charged, the switching tube Q201 is turned on immediately after the freewheeling period is entered, and the above steps are repeated. Therefore, the first implementation circuit provided by the embodiment of the present invention adjusts the resistance variation of the variable resistor to control the on-off duration ratio of the MOS transistor Q101, thereby changing the current magnitude of the load circuit 40.
A second implementation circuit comprising: the constant current driving chip U1, the second resistor R2, the third resistor R3 and the fourth resistor R4; as shown in fig. 4, the 1 st pin GND of the constant current driving chip U1 is electrically connected to the negative electrode of the voltage source Vin, the 2 nd pin ROVP is electrically connected to one end of the fourth resistor R4 to set a trigger start point voltage value of the output open circuit voltage, the 3 rd pin RLED is electrically connected to the control end of the control circuit module 10 to control the slope of the current curve of the load circuit 40 by adjusting the variation of the output current according to a predefined adjustment parameter by the control circuit module 10 under the over-temperature protection condition, the 4 th pin Vin is electrically connected to the positive electrode of the voltage source Vin, the 5 th pin DRA is electrically connected to the load circuit 40, the 6 th pin CS is electrically connected to one end of the second resistor R2 to control the maximum peak current value of the current flowing through the external inductor, the 7 th pin RTH is electrically connected to one end of the third resistor R3 to control the start point temperature value at which the over-temperature protection is triggered, and the other ends of the second resistor R2, the third resistor R3 and the other end of the fourth resistor R4 are electrically connected to the positive electrode of the voltage source Vin. The constant current driving chip U1 is obtained by integrating a first implementation circuit, so the working principle of a second implementation circuit is the same as that of the first implementation circuit, as shown in fig. 2, when the MOS transistor Q101 is turned on, the current I LED of the LED lamp flows through one end of the sampling resistor R1 through the first inductor L101, and the voltage drop generated on the sampling resistor R1 is as follows: vcs=2r1×i LED, the voltage VCS thus generated is detected by the 6 th pin CS of the constant current driving chip U1 and is then used for comparison with the reference voltage of the internal comparator, thereby controlling the duration of the on period of the internal MOS transistor Q101, thereby changing the current level of the load circuit 40.
Alternatively, the control circuit module 10 described in the above embodiment may include: a capacitance-adjustable module and/or a resistance-adjustable module and/or a voltage-adjustable module; one end of the capacitance adjustable module is electrically connected with the controlled end of the driving module 30, and the other end of the capacitance adjustable module is grounded; one end of the resistance adjustable module is electrically connected with the controlled end of the driving module 30, and the other end of the resistance adjustable module is grounded; one end of the voltage adjustable module is electrically connected with the controlled end of the driving module 30, and the other end of the voltage adjustable module is grounded.
In particular implementations, the resistance adjustable module may include: an adjustable resistor R LED, one end of the adjustable resistor R LED is electrically connected to the controlled end of the driving module 30, and the other end of the adjustable resistor R LED is grounded. Preferably, to filter out signal interference of the adjustable resistor R LED, the resistor adjustable module includes: the second capacitor C2 is connected in parallel with the adjustable resistor R LED.
As shown in fig. 2 to 5, an LED lamp provided by an embodiment of the present invention may include: the over-temperature protection circuit, the first inductor L101, the first diode D101, and the load circuit 40. The connection relationship and the operation relationship between the overheat protection circuit and the load circuit 40 are described in detail below, and the details are as follows:
One end of the load circuit 40 is connected to the negative electrode of the first diode D101 at the third connection point 3, the other end of the load circuit 40 is connected to the fifth connection point 5 at one end of the first inductor L101, and the other end of the first inductor L101, the over-temperature protection circuit and the positive electrode of the first diode D101 are connected to the fourth connection point 4.
The load circuit 40 may include at least one LED lamp and a fifth resistor R5, where the at least one LED lamp is connected in series to form an LED lamp group, one end of the LED lamp group and one end of the fifth resistor R5 are connected to the third connection point 3, and the other end of the LED lamp group and the other end of the fifth resistor R5 are connected to the fifth connection point 5. Preferably, in order to filter out the ripple current of the LED lamp set, the load circuit 40 may include: and one end of the third capacitor C3 is electrically connected with the third connection point 3, and the other end of the third capacitor C3 is electrically connected with the fifth connection point 5. According to the embodiment of the invention, the ripple current of the LED lamp group can be filtered through the third capacitor C3, so that the high-quality light output effect of the LED lamp group with low stroboscopic effect or without stroboscopic effect is realized.
Wherein, at least one LED lamp includes: bulb lamp, down lamp or panel lamp. Of course, the at least one LED lamp may also include other types of lamps in the prior art, and embodiments of the present invention are not particularly limited.
The over-temperature protection circuit adopts the over-temperature protection circuit described in the embodiment of the invention, and referring to fig. 1, the over-temperature protection circuit may include: a control circuit module 10 for adjusting the variation of the output current according to a predefined adjustment parameter during the over-temperature protection process, a temperature detection module 20 for detecting the temperature variation of the circuit in which the load is located and generating a control logic signal according to the temperature variation, and a driving module 30. The connection and operation relationships among the control circuit module 10, the temperature detection module 20, and the driving module 30 are described below, and in detail, as shown in fig. 1 and 2, as follows:
The control circuit module 10 has a first control terminal 11 and controls the amount of change in the output current, which is obtained from a predefined regulation parameter, which may include a regulation voltage, a regulation resistance or a regulation capacitance, via the first control terminal 11. The specific implementation circuit of the control circuit module 10 may be a circuit for converting resistance values, a circuit for converting voltage values, a circuit for converting capacitance values, for example, a circuit including a sliding rheostat.
The temperature detection module 20 has an output terminal 21, and outputs a control logic signal through the output terminal 21, where the control logic signal is obtained according to the temperature variation of the circuit where the load is located. The specific implementation circuit of the temperature detection module 20 may be a circuit having a temperature detection device and capable of processing a temperature variation amount. For example, a circuit with a device or temperature sensor that is sensitive to ambient temperature.
The driving module 30 has a second control terminal 31, an input terminal 33 and a controlled terminal 32, the input terminal 33 is electrically connected with the output terminal 21, the controlled terminal 32 is electrically connected with the first control terminal 11, the second control terminal 31 is electrically connected with the load circuit 40, wherein the driving module 30 controls the slope of the current curve of the load circuit 40 through the second control terminal 31 by the variation of the output current obtained by the controlled terminal 32 and the control logic signal input by the input terminal 33. Specifically, the driving module 30 may have a MOS transistor Q101, where a drain D of the MOS transistor Q101 is electrically connected to the load circuit 40, and the driving module 30 drives a duration of turning on or off the MOS transistor Q101 by a variable amount of an output current obtained by the control terminal 32 and a control logic signal input by the input terminal 33, and controls a current change of the load circuit 40 according to a ratio of the duration of turning on to the duration of turning off the MOS transistor Q101, so as to control a slope of a current curve of the load circuit 40, as shown in fig. 5.
Of course, the over-temperature protection circuit may further include other electrical devices, and details of the related content in the above embodiment of the present invention are not described herein.
According to the embodiment of the invention, the over-temperature protection circuit is arranged and comprises a control circuit module, a temperature detection module and a driving module, wherein a first control end of the control circuit module is electrically connected with a controlled end of the driving module, an output end of the temperature detection module is electrically connected with an input end of the driving module, and a second control end of the driving module is electrically connected with a load circuit. The control circuit module is used for adjusting the variation of the output current according to a predefined regulation parameter in the over-temperature protection process, the temperature detection module is used for detecting the temperature variation of a circuit where the load is located and generating a control logic signal according to the temperature variation, and the driving module controls the slope of a current curve of the load circuit through the variation of the output current obtained by the controlled end and the control logic signal input by the input end and the second control end. Therefore, the over-temperature protection circuit provided by the embodiment of the invention can be matched with application conditions to adjust the slope of the current curve of the load circuit, and meanwhile, the change curve of the output current of the load circuit can achieve the optimal dimming curve effect under different LED lamp application conditions, so that the reliability of the actual application of the LED lamp is improved, and meanwhile, the excellent optical quality effect of the LED lamp in the over-temperature protection process is also improved.
It will be apparent to those skilled in the art that while preferred embodiments of the present invention have been described, additional variations and modifications may be made to these embodiments once the basic inventive concepts are known to those skilled in the art. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (9)
1. An over-temperature protection circuit, comprising:
The control circuit module is configured to adjust the variation of the output current according to a predefined adjustment parameter in the process of over-temperature protection, and is provided with a first control end, and the variation of the output current is controlled through the first control end;
The temperature detection module is configured to detect the temperature variation of a circuit in which the load is positioned and generate a control logic signal according to the temperature variation, and is provided with an output end, and the control logic signal is output through the output end;
the driving module is provided with a second control end, an input end and a controlled end, wherein the input end is electrically connected with the output end, the controlled end is electrically connected with the first control end, the second control end is electrically connected with the load circuit,
The driving module controls the current change of the load circuit through the second control end by the variable quantity of the output current obtained by the controlled end and the control logic signal input by the input end so as to control the slope of the current curve of the load circuit;
The control circuit module includes: a capacitance-adjustable module and/or a resistance-adjustable module and/or a voltage-adjustable module;
One end of the capacitance adjustable module is electrically connected with the controlled end of the driving module, and the other end of the capacitance adjustable module is grounded;
One end of the resistance adjustable module is electrically connected with the controlled end of the driving module, and the other end of the resistance adjustable module is grounded;
One end of the voltage adjustable module is electrically connected with the controlled end of the driving module, and the other end of the voltage adjustable module is grounded.
2. The over-temperature protection circuit according to claim 1, wherein the driving module has a MOS transistor, a drain of which is electrically connected to the load circuit;
The driving module controls the current change of the load circuit by driving the on-off time length of the MOS transistor and according to the proportion of the on-time length and the off-time length of the MOS transistor so as to control the slope of the current curve of the load circuit.
3. The over-temperature protection circuit of claim 2, wherein the driving module comprises: the device comprises a first comparator, a second comparator, a current mirror, a switching tube, a first capacitor, a first resistor, a sampling resistor, a logic control unit and a driving signal processing unit; wherein,
The first input end of the first comparator is electrically connected with a first reference voltage, the second input end of the first comparator, the drain electrode of the switching tube, one end of the first capacitor and one end of the current mirror are electrically connected with a first connection point, and the output end of the first comparator is electrically connected with the delay access end of the logic control unit;
The first input end of the second comparator is electrically connected with a second reference voltage, and the second input end of the second comparator, the other end of the current mirror and the control end of the control circuit module are electrically connected with a second connection point;
The first output end of the logic control unit is electrically connected with one end of the first resistor, the other end of the first resistor is electrically connected with the grid electrode of the switch tube, the second output end of the logic control unit is electrically connected with the driving signal processing unit, the driving signal processing unit is electrically connected with the grid electrode of the MOS transistor, the source electrode of the MOS transistor is electrically connected with one end of the sampling resistor, and the other end of the sampling resistor is grounded;
The logic control unit generates a driving signal according to the output signal of the first comparator and other control logic signals, and sends the driving signal to the driving signal processing unit, and the driving signal processing unit generates a driving instruction according to the driving signal so as to drive the MOS transistor to be turned on or turned off.
4. An over-temperature protection circuit according to any one of claims 1 to 3, wherein the driving module comprises: the constant current driving chip, the second resistor, the third resistor and the fourth resistor; wherein,
The 1 st pin of the constant current driving chip is electrically connected with the negative electrode of the voltage source, the 2 nd pin is electrically connected with one end of the fourth resistor to set a triggering starting point voltage value of the output open-circuit voltage, the 3 rd pin is electrically connected with the control end of the control circuit module to control the slope of a current curve of the load circuit by adjusting the variation of the output current according to a predefined adjusting parameter through the control circuit module under the over-temperature protection condition, the voltage source positive pole is connected to the 4 th foot electricity, and the load circuit is connected to the 5 th foot electricity, and the 6 th foot electricity is connected the one end of second resistance to the maximum peak current value of the electric current of control external inductance that flows through, the 7 th foot electricity is connected one end of third resistance, with the starting point temperature value that control over temperature protection was triggered, the other end of second resistance, the other end of third resistance and the other end of fourth resistance electricity are connected the voltage source positive pole.
5. The over-temperature protection circuit of claim 1, wherein the resistance adjustable module comprises: an adjustable resistance;
one end of the adjustable resistor is electrically connected with the controlled end of the driving module, and the other end of the adjustable resistor is grounded.
6. The over-temperature protection circuit of claim 5, wherein the resistance adjustable module comprises: a second capacitor;
the second capacitor is connected in parallel with the adjustable resistor.
7. An LED lamp is characterized by comprising the over-temperature protection circuit, a first inductor, a first diode and a load circuit according to any one of the claims 1-6;
One end of the load circuit is connected with the cathode of the first diode, the other end of the load circuit is connected with one end of the first inductor to form a fifth connection point, and the other end of the first inductor, the over-temperature protection circuit and the anode of the first diode are connected with a fourth connection point.
8. The LED light fixture of claim 7 wherein the load circuit comprises at least one LED lamp and a fifth resistor, the at least one LED lamp being connected in series to form an LED lamp group, one end of the LED lamp group and one end of the fifth resistor being connected to the third connection point, the other end of the LED lamp group and the other end of the fifth resistor being connected to the fifth connection point.
9. The LED light fixture of claim 8 wherein the load circuit comprises:
and one end of the third capacitor is electrically connected with the third connection point, and the other end of the third capacitor is electrically connected with the fifth connection point.
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| CN201910663315.7A CN110381637B (en) | 2019-07-22 | 2019-07-22 | Over-temperature protection circuit and LED lamp |
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| CN112235895B (en) * | 2020-09-10 | 2023-06-02 | 深圳市崧盛电子股份有限公司 | Over-temperature protection circuit and driving power supply |
| CN112351547B (en) * | 2020-12-04 | 2022-05-10 | 华源智信半导体(武汉)有限公司 | Intelligent adjusting method and system for driving LED |
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| CN110381637A (en) | 2019-10-25 |
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