CN111194110A - Signal conversion circuit, LED drive power supply and LED lamp - Google Patents
Signal conversion circuit, LED drive power supply and LED lamp Download PDFInfo
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- CN111194110A CN111194110A CN202010156534.9A CN202010156534A CN111194110A CN 111194110 A CN111194110 A CN 111194110A CN 202010156534 A CN202010156534 A CN 202010156534A CN 111194110 A CN111194110 A CN 111194110A
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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
- H05B44/00—Circuit arrangements for operating electroluminescent light sources
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V23/00—Arrangement of electric circuit elements in or on lighting devices
- F21V23/003—Arrangement of electric circuit elements in or on lighting devices the elements being electronics drivers or controllers for operating the light source, e.g. for a LED array
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
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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 a signal conversion circuit, which comprises an isolation conversion unit, a signal conversion unit and a signal conversion unit, wherein the isolation conversion unit is used for receiving a PWM signal and converting the PWM signal into an output signal through isolation transmission; the voltage stabilizing unit is connected with the isolation conversion unit and is used for providing stable reference voltage for the conversion of the PWM signals; the voltage regulating unit is connected with the isolation conversion unit and the voltage stabilizing unit and is used for regulating and controlling the voltage amplitude of the output signal; the input end of the voltage following unit is connected with the voltage regulating unit, and the output end of the voltage following unit is connected with the controller and used for stably outputting the output signal to the controller; and the power supply unit is connected with the voltage stabilizing unit and the voltage following unit and is used for supplying power to the voltage stabilizing unit and the voltage following unit. The invention can adjust the output signal, reduce the interference and improve the precision and the stability of the output signal.
Description
Technical Field
The invention relates to the technical field of switching power supplies, in particular to a signal conversion circuit, an LED driving power supply and an LED lamp.
Background
In the design of an LED outdoor driving power supply, a signal conversion circuit is a very critical link. As shown in fig. 1, fig. 1 is a conventional signal conversion circuit, in which a resistor R1 and a capacitor C1 are filter circuits, and a resistor R2 and a resistor R3 are voltage dividing circuits. In the traditional signal conversion circuit, an output signal follows an input signal, the output signal is difficult to adjust, and the output signal is derived from the input signal, is greatly interfered, has poor control signal precision and is not suitable for high-precision signal control. In addition, in the state of input signal delay or no input signal, the output signal can not effectively maintain a small voltage, so as to realize the control of the controller.
Disclosure of Invention
The invention provides a signal conversion circuit, an LED driving power supply and an LED lamp, and aims to solve the problems that in the related art, output signals are difficult to adjust, the accuracy is poor, and the output signals cannot effectively maintain smaller voltage to realize the control of a controller under the condition that input signals are delayed or no input signals exist.
In a first aspect, the present invention provides a signal conversion circuit, including: the isolation conversion unit is used for receiving the PWM signals and converting the PWM signals into output signals in an isolation transmission mode; the voltage stabilizing unit is connected with the isolation conversion unit and is used for providing stable reference voltage for the conversion of the PWM signals; the voltage regulating unit is connected with the isolation conversion unit and the voltage stabilizing unit and is used for regulating and controlling the voltage amplitude of the output signal; the input end of the voltage following unit is connected with the voltage regulating unit, and the output end of the voltage following unit is connected with the controller and used for stably outputting the output signal to the controller; the power supply unit is connected with the voltage stabilizing unit and the voltage following unit and used for supplying power to the voltage stabilizing unit and the voltage following unit; the voltage regulating unit is further used for being connected with the controller, and when the PWM signal is not input, the power supply unit outputs a control voltage signal to the controller through the voltage regulating unit through the voltage stabilizing unit.
Further, the power supply unit comprises a first resistor, a second resistor, a third resistor, a first diode, a second diode, a first voltage-stabilizing tube and a first capacitor, wherein the anode of the first diode is connected with a first power supply, the cathode of the first diode is connected with one end of the third resistor, the other end of the third resistor is connected with the voltage-stabilizing unit, one end of the first resistor is connected with the first power supply, the other end of the first resistor is connected between the cathode of the first diode and the third resistor, the cathode of the first voltage-stabilizing tube is connected between the cathode of the first diode and the third resistor, the anode of the first voltage-stabilizing tube is grounded, the first capacitor is connected in parallel with the first voltage-stabilizing tube, the anode of the second diode is connected with the high-voltage starting circuit, the cathode of the second diode is connected between the cathode of the first diode and the third resistor, one end of the second resistor is connected between the cathode of the first diode and the third resistor, and the other end of the second resistor is connected with the voltage following unit.
Further, the voltage stabilizing unit includes a fourth resistor, a fifth resistor, a sixth resistor, a second capacitor, a third capacitor, and a voltage stabilizing chip, one end of the sixth resistor is connected to the isolation conversion unit and the voltage adjustment unit, the other end of the sixth resistor is connected to the third resistor, an output end of the voltage stabilizing chip is connected between the sixth resistor and the third resistor, a ground end of the voltage stabilizing chip is grounded, one end of the fourth resistor is connected to an input end of the voltage stabilizing chip, the other end of the fourth resistor is grounded, one end of the fifth resistor is connected between the sixth resistor and the third resistor, the other end of the fifth resistor is connected to an output end of the voltage stabilizing chip and connected to the voltage adjustment unit, one end of the second capacitor is connected between the sixth resistor and the third resistor, the other end of the second capacitor is connected with the input end of the voltage stabilizing chip, one end of the third capacitor is connected between the sixth resistor and the third resistor, and the other end of the third capacitor is grounded.
Further, the isolation conversion unit comprises a seventh resistor, a twenty-first resistor and an optocoupler, the anode of a light emitting diode of the optocoupler is connected with a second power supply, the cathode of the light emitting diode is connected with one end of the twenty-first resistor, the other end of the twenty-first resistor is used for inputting the PWM signal, the emitting electrode of a phototriode of the optocoupler is grounded, the collecting electrode of the phototriode is connected with one end of the seventh resistor, and the other end of the seventh resistor is connected with the other end of the sixth resistor and the voltage regulation unit.
Further, the voltage adjusting unit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, and an adjustable resistor, one end of the eighth resistor is connected between the sixth resistor and the seventh resistor, the other end of the eighth resistor is connected with the voltage following unit, one end of the ninth resistor is connected between the eighth resistor and the voltage following unit, the other end of the ninth resistor is connected with one end of the tenth resistor, the other end of the tenth resistor is grounded, one end of the eleventh resistor is grounded, the other end of the eleventh resistor is connected with one end of the adjustable resistor, the other end of the adjustable resistor is connected between the ninth resistor and the tenth resistor, and one end of the twelfth resistor is connected between the eleventh resistor and the adjustable resistor, the other end of the twelfth resistor is connected with the fifth resistor.
Further, the voltage following unit includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a third diode, and an operational amplifier, a power supply terminal of the operational amplifier is connected to the other end of the second resistor, a ground terminal of the operational amplifier is grounded, an output terminal of the operational amplifier is connected to an anode of the third diode, a cathode of the third diode is configured to be connected to the controller, the seventeenth resistor is connected to the third diode in parallel, a non-inverting input terminal of the operational discharger is connected to one end of the sixth capacitor, the other end of the sixth capacitor is grounded and connected to one end of the fourth capacitor, the other end of the fourth capacitor is connected to one end of the fourteenth resistor, and the other end of the fourteenth resistor is configured to be connected to the controller, one end of the sixteenth resistor is connected between the non-inverting input end of the operational amplifier and the sixth capacitor, the other end of the sixteenth resistor is connected with one end of the fifth capacitor, the other end of the fifth capacitor is connected with one end of the fifteenth resistor, the other end of the fifteenth resistor is used for being connected with the controller, one end of the thirteenth resistor is connected between the eighth resistor and the ninth resistor, and the other end of the thirteenth resistor is connected between the fourth capacitor and the fourteenth resistor and between the sixteenth resistor and the fifth capacitor.
Furthermore, the over-temperature protection circuit further comprises an over-temperature protection unit, wherein one end of the over-temperature protection unit is connected with the power supply unit, the other end of the over-temperature protection unit is connected with the output end of the voltage following unit and the voltage adjusting unit, and the over-temperature protection unit is used for reducing the voltage of the output signal or the control voltage signal to reduce the temperature.
Further, the over-temperature protection unit comprises an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a thermistor, a seventh capacitor, a second voltage regulator tube and a triode, wherein one end of the thermistor is connected between the anode of the first diode and the first power supply, the other end of the thermistor is connected with the cathode of the second voltage regulator tube, the anode of the second voltage regulator tube is connected with the base electrode of the triode, the collector electrode of the triode is connected with one end of the eighteenth resistor, the other end of the eighteenth resistor is connected between the fourteenth resistor and the controller, the emitter electrode of the triode is grounded, one end of the nineteenth resistor is connected between the base electrode of the triode and the anode of the second voltage regulator tube, the other end of the nineteenth resistor is grounded, and the seventh capacitor is connected with the nineteenth resistor in parallel, one end of the twentieth resistor is connected between the negative electrode of the second voltage regulator tube and the thermistor, and the other end of the twentieth resistor is grounded.
In a second aspect, the present invention further provides an LED driving power supply, which includes a signal conversion circuit, where the signal conversion circuit is the signal conversion circuit according to the first aspect.
In a third aspect, the present invention further provides an LED lamp, which includes an LED driving power supply, where the LED driving power supply is the LED driving power supply of the second aspect.
Compared with the prior art, the invention has the beneficial effects that: the PWM signal is transmitted in an isolation mode to be converted into the output signal through the isolation conversion unit, the voltage stabilizing unit provides reference voltage for PWM signal conversion, the voltage adjusting unit can adjust the voltage amplitude of the output signal, the output signal is output to the controller through the voltage following unit to achieve control over the controller, the output signal can be adjusted, interference is reduced, accuracy and stability of the output signal are improved, and the control voltage signal can effectively maintain smaller voltage under the condition that the input signal is delayed or no input signal exists, so that control over the controller is achieved, and reliability is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 shows a schematic diagram of a prior art signal conversion circuit;
FIG. 2 is a schematic diagram of a signal conversion circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a signal conversion circuit according to another embodiment of the present invention;
fig. 4 shows a circuit diagram of the signal conversion circuit provided in the embodiment shown in fig. 3.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
Referring to fig. 2-4, an embodiment of the signal conversion circuit 100 provided by the present invention is shown. The signal conversion circuit 100 includes: the isolation conversion unit 10 is used for receiving the PWM signals and converting the PWM signals into output signals in an isolation transmission mode; the voltage stabilizing unit 20 is connected with the isolation conversion unit 10, and is used for providing a stable reference voltage for the conversion of the PWM signal; the voltage adjusting unit 30, the voltage adjusting unit 30 is connected to the isolation converting unit 10 and the voltage stabilizing unit 20, and is used for adjusting and controlling the voltage amplitude of the output signal; the input end of the voltage following unit 40 is connected with the voltage regulating unit 30, and the output end of the voltage following unit 40 is used for being connected with the controller 70 and stably outputting the output signal to the controller 70; the power supply unit 50 is connected with the voltage stabilizing unit 20 and the voltage following unit 40, and is used for supplying power to the voltage stabilizing unit 20 and the voltage following unit 40; the voltage adjusting unit 30 is further configured to be connected to the controller 70, and when the PWM signal is not input, the power supply unit 50 outputs a control voltage signal to the controller 70 through the voltage regulating unit 30 by the voltage stabilizing unit 20. By implementing the embodiment, when the PWM signal is input, the input PWM signal is isolated, transmitted and converted into the output signal through the isolation conversion unit 10, and the voltage stabilization unit 20 converts the PWM signal to increase the reference voltage, in addition, the voltage adjustment unit 30 can adjust the voltage amplitude of the output signal, and the output signal is output to the controller 70 through the voltage following unit 40 to control the controller 70, thereby realizing the adjustment of the output signal and improving the precision and stability of the output signal. When no PWM signal is input, the power supply unit 50 supplies power to the voltage stabilizing unit 20, and the voltage stabilizing unit 20 outputs a voltage control signal to the controller 70 through the voltage adjusting unit 30, so that a small voltage can be maintained even in a state where an input signal is delayed or no input signal is present, thereby controlling the controller 70 and improving reliability.
In an embodiment, for example, in this embodiment, the power supply unit 50 includes a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, a first zener diode ZD1, and a first capacitor C1, an anode of the first diode D1 is connected to a first power supply, a cathode of the first diode D1 is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to the voltage stabilizing unit 20, one end of the first resistor R1 is connected to the first power supply, the other end of the first resistor R1 is connected between the cathode of the first diode D1 and the third resistor R3, a cathode of the first zener diode 1 is connected between the cathode of the first diode D1 and the third resistor R3, an anode of the first zener diode ZD1 is grounded, and the first capacitor C1 is connected in parallel to the first diode ZD 67 1, the anode of the second diode D2 is connected to the high voltage starting circuit C, the cathode of the second diode D2 is connected between the cathode of the first diode D1 and the third resistor R3, one end of the second resistor R2 is connected between the cathode of the first diode D1 and the third resistor R3, and the other end of the second resistor R2 is connected to the voltage following unit 40. In this embodiment, the first power supply is VCC. The high-voltage starting circuit C provides a starting voltage for the voltage stabilizing chip U1 and the operational amplifier U3 through a second diode D2 and a first voltage stabilizing tube ZD1, and a power supply circuit is formed by a first diode D1, a first capacitor C1, a second resistor R2 and a third resistor R3 and provides a power supply voltage for the voltage stabilizing chip U1 and the operational amplifier U3.
In an embodiment, for example, in this embodiment, the voltage stabilizing unit 20 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a second capacitor C2, a third capacitor C3, and a voltage stabilizing chip U1, one end of the sixth resistor R6 is connected to the isolation transformation unit 10 and the voltage adjusting unit 30, the other end of the sixth resistor R6 is connected to the third resistor R3, an output end of the voltage stabilizing chip U1 is connected between the sixth resistor R6 and the third resistor R3, a ground end of the voltage stabilizing chip U1 is grounded, one end of the fourth resistor R4 is connected to an input end of the voltage stabilizing chip U1, the other end of the fourth resistor R4 is grounded, one end of the fifth resistor R5 is connected between the sixth resistor R6 and the third resistor R3, the other end of the fifth resistor R5 is connected to an output end of the voltage stabilizing chip U1 and the voltage adjusting unit 30, one end of the second capacitor C2 is connected between the sixth resistor R6 and the third resistor R3, the other end of the second capacitor C2 is connected to the input end of the voltage stabilization chip U1, one end of the third capacitor C3 is connected between the sixth resistor R6 and the third resistor R3, and the other end of the third capacitor C3 is grounded. The voltage stabilizing unit 20 in this embodiment provides a reference voltage when the PWM signal is converted, so that interference is reduced and the accuracy of the signal is improved.
In an embodiment, for example, in this embodiment, the isolation conversion unit 10 includes a seventh resistor R7, a twenty-first resistor R21, and an optocoupler U2, an anode of a light emitting diode of the optocoupler U2 is connected to a second power supply, a cathode of the light emitting diode is connected to one end of the twenty-first resistor R21, the other end of the twenty-first resistor R21 is used to input the PWM signal (ADJ), an emitter of a phototransistor of the optocoupler U2 is grounded, a collector of the phototransistor is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the other end of the sixth resistor R6 and the voltage adjustment unit 30. In the present embodiment, the second power supply is a 5V power supply, and the isolation conversion unit 10 in the present embodiment electrically isolates the PWM signal, thereby achieving efficient conversion of the isolated PWM signal.
In one embodiment, for example, in the present embodiment, the voltage adjusting unit 30 includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12 and an adjustable resistor VR1, one end of the eighth resistor R8 is connected between the sixth resistor R6 and the seventh resistor R7, the other end of the eighth resistor R8 is connected to the voltage following unit 40, one end of the ninth resistor R9 is connected between the eighth resistor R8 and the voltage following unit 40, the other end of the ninth resistor R9 is connected to one end of the tenth resistor R10, the other end of the tenth resistor R10 is grounded, one end of the eleventh resistor R11 is grounded, the other end of the eleventh resistor R11 is connected to one end of the adjustable resistor VR1, the other end of the adjustable resistor VR1 is connected between the ninth resistor R9 and the tenth resistor R10, one end of the twelfth resistor R12 is connected between the eleventh resistor R11 and the adjustable resistor VR1, and the other end of the twelfth resistor R12 is connected with the fifth resistor R5. The voltage adjusting unit 30 in this embodiment can adjust the voltage of the converted output signal when the PWM signal is input, thereby adjusting the output signal.
In one embodiment, for example, in this embodiment, the voltage follower unit 40 includes a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a third diode D3, and an operational amplifier U3, a power supply terminal of the operational amplifier U3 is connected to the other terminal of the second resistor R2, a ground terminal of the operational amplifier U3 is grounded, an output terminal of the operational amplifier U3 is connected to an anode of the third diode D3, a cathode of the third diode D3 is used to be connected to the controller 70(F), a seventeenth resistor R17 is connected to the third diode D3 in parallel, a non-inverting input terminal of the operational amplifier is connected to one terminal of the sixth capacitor C6, the other terminal of the sixth capacitor C6 is grounded and connected to one terminal of the fourth capacitor C4, the other end of the fourth capacitor C4 is connected to one end of the fourteenth resistor R14, the other end of the fourteenth resistor R14 is used for connecting to the controller 70(F), one end of the sixteenth resistor R16 is connected between the non-inverting input terminal of the operational amplifier U3 and the sixth capacitor C6, the other end of the sixteenth resistor R16 is connected to one end of the fifth capacitor C5, the other end of the fifth capacitor C5 is connected to one end of the fifteenth resistor R15, the other end of the fifteenth resistor R15 is used for connecting with the controller 70(F), one end of the thirteenth resistor R13 is connected between the eighth resistor R8 and the ninth resistor R9, the other end of the thirteenth resistor R13 is connected between the fourth capacitor C4 and the fourteenth resistor R14, and between the sixteenth resistor R16 and the fifth capacitor C5. In this embodiment, the thirteenth resistor R13 and the fourth capacitor C4 form a filter for smoothing the output signal; the fifth capacitor C5 and the fifteenth resistor R15 are used for being quickly conducted to prevent oscillation; the sixth capacitor C6 is used for filtering high-frequency signals at the input end of the operational amplifier U3, so that the risk of high-frequency self-excitation of the amplifier is reduced; the operational amplifier U3, the third diode D3, the sixteenth resistor R16 and the sixth capacitor C6 form a voltage follower, so that the accuracy of output signals is improved, and the interference resistance is improved. The voltage follower unit 40 of the present embodiment can stably output the output signal to the controller 70, ensuring stability and reliability of the output signal.
In an embodiment, for example, in this embodiment, the signal converting circuit 100 further includes an over-temperature protection unit 60, one end of the over-temperature protection unit 60 is connected to the power supply unit 50, and the other end of the over-temperature protection unit 60 is connected to the output end of the voltage following unit 40 and the voltage regulating unit 30, and is configured to pull down the voltage of the output signal or the control voltage signal to reduce the temperature when the temperature is over-temperature.
In a specific implementation, the over-temperature protection unit 60 includes an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a thermistor RT2, a seventh capacitor C7, a second voltage regulator ZD2, and a triode Q1, one end of the thermistor RT2 is connected between the positive electrode of the first diode D1 and the first power supply, the other end of the thermistor RT2 is connected with the negative electrode of the second voltage regulator ZD2, the positive electrode of the second voltage regulator ZD2 is connected with the base of the triode Q1, the collector of the triode Q1 is connected with one end of the eighteenth resistor R18, the other end of the eighteenth resistor R18 is connected between the fourteenth resistor R14 and the controller 70, the emitter of the triode Q1 is grounded, one end of the nineteenth resistor R19 is connected between the base of the triode Q1 and the positive electrode of the second voltage regulator ZD2, the other end of the nineteenth resistor R19 is grounded, the seventh capacitor C7 is connected in parallel with the nineteenth resistor R19, one end of the twentieth resistor R20 is connected between the negative electrode of the second voltage regulator tube ZD2 and the thermistor RT2, and the other end of the twentieth resistor R20 is grounded.
Specifically, when the temperature rises, the resistance value of the thermistor RT2 decreases, the voltage across the twentieth resistor R20 increases, and the increased voltage exceeds the voltage of the second voltage regulator tube ZD2, the triode Q1(NPN) is turned on, and the voltage of the output signal or the voltage of the control voltage signal is pulled down by the eighteenth resistor R18, so that the temperature protection effect is achieved by reducing the voltage, and the overheating damage of components is avoided.
In another embodiment, when no PWM signal is input, the voltage regulator unit 20 including the first resistor R1, the third resistor R3, the fourth resistor R4, the second capacitor C2 and the voltage regulator chip U1 provides a stable reference voltage, and the voltage regulator unit 30 includes the sixth resistor R6, the eighth resistor R8, the ninth resistor R9, the twelfth resistor R12, the adjustable resistor VR1, the thirteenth resistor R13, the fourteenth resistor R14 and the fourth capacitor C4, so as to regulate the control voltage signal. Therefore, in the state of input signal delay or no input signal, the reference voltage of the voltage stabilizing unit 20 is used to provide the control voltage signal, the voltage adjusting unit 30 is used to adjust and transmit the control voltage signal, the control voltage signal is output to the controller 70, and the controller 70 is effectively controlled by maintaining a small voltage.
The embodiment of the signal conversion circuit 100 of the invention performs isolated transmission on the PWM signal by the isolated conversion unit 10 to convert the PWM signal into the output signal, the voltage stabilizing unit 20 provides the reference voltage for PWM signal conversion, the voltage adjusting unit 30 can adjust the voltage amplitude of the output signal, the output signal is output to the controller 70 through the voltage following unit 40 to realize control on the controller 70, the output signal can be adjusted, interference is reduced, and the precision and stability of the output signal are improved, and the control voltage signal can effectively maintain a smaller voltage in the state of input signal delay or no input signal, so as to realize control on the controller 70 and improve reliability.
The present invention further discloses an LED driving power supply, which includes a signal conversion circuit 100, where the signal conversion circuit 100 is the signal conversion circuit 100 described in the above embodiments, and other circuit components included in the LED driving power supply are well known to those skilled in the art and are not described herein again.
According to the embodiment of the LED driving power supply, the PWM signal is transmitted in an isolation mode through the isolation conversion unit 10 and converted into the output signal, the voltage stabilizing unit 20 provides the reference voltage for the PWM signal conversion, the voltage adjusting unit 30 can adjust the voltage amplitude of the output signal, the output signal is output to the controller 70 through the voltage following unit 40 to achieve control over the controller 70, the output signal can be adjusted, interference is reduced, accuracy and stability of the output signal are improved, and the control voltage signal can effectively maintain a small voltage under the condition that the input signal is delayed or no input signal exists, so that control over the controller 70 is achieved, and reliability is improved.
The invention also discloses an LED lamp, which comprises an LED driving power supply, wherein the LED driving power supply is the LED driving power supply in the embodiment, and the details are not repeated herein.
According to the embodiment of the LED lamp, the PWM signal is transmitted in an isolated mode through the isolation conversion unit 10 and converted into the output signal, the voltage stabilizing unit 20 provides the reference voltage for the PWM signal conversion, the voltage adjusting unit 30 can adjust the voltage amplitude of the output signal, the output signal is output to the controller 70 through the voltage following unit 40 to achieve control over the controller 70, the output signal can be adjusted, interference is reduced, accuracy and stability of the output signal are improved, and the control voltage signal can effectively maintain a small voltage under the condition that the input signal is delayed or no input signal exists, so that control over the controller 70 is achieved, and reliability is improved.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A signal conversion circuit, comprising:
the isolation conversion unit is used for receiving the PWM signals and converting the PWM signals into output signals in an isolation transmission mode;
the voltage stabilizing unit is connected with the isolation conversion unit and is used for providing stable reference voltage for the conversion of the PWM signals;
the voltage regulating unit is connected with the isolation conversion unit and the voltage stabilizing unit and is used for regulating and controlling the voltage amplitude of the output signal;
the input end of the voltage following unit is connected with the voltage regulating unit, and the output end of the voltage following unit is connected with the controller and used for stably outputting the output signal to the controller;
the power supply unit is connected with the voltage stabilizing unit and the voltage following unit and used for supplying power to the voltage stabilizing unit and the voltage following unit;
the voltage regulating unit is further used for being connected with the controller, and when the PWM signal is not input, the power supply unit outputs a control voltage signal to the controller through the voltage regulating unit through the voltage stabilizing unit.
2. The signal conversion circuit according to claim 1, wherein the power supply unit comprises a first resistor, a second resistor, a third resistor, a first diode, a second diode, a first voltage regulator tube and a first capacitor, wherein an anode of the first diode is connected with a first power supply, a cathode of the first diode is connected with one end of the third resistor, the other end of the third resistor is connected with the voltage regulator unit, one end of the first resistor is connected with the first power supply, the other end of the first resistor is connected between the cathode of the first diode and the third resistor, a cathode of the first voltage regulator tube is connected between the cathode of the first diode and the third resistor, an anode of the first voltage regulator tube is grounded, the first capacitor is connected in parallel with the first voltage regulator tube, and an anode of the second diode is connected with the high voltage starting circuit, the cathode of the second diode is connected between the cathode of the first diode and the third resistor, one end of the second resistor is connected between the cathode of the first diode and the third resistor, and the other end of the second resistor is connected with the voltage following unit.
3. The signal converting circuit according to claim 2, wherein the voltage stabilizing unit comprises a fourth resistor, a fifth resistor, a sixth resistor, a second capacitor, a third capacitor and a voltage stabilizing chip, one end of the sixth resistor is connected to the isolation converting unit and the voltage regulating unit, the other end of the sixth resistor is connected to the third resistor, an output end of the voltage stabilizing chip is connected between the sixth resistor and the third resistor, a ground end of the voltage stabilizing chip is grounded, one end of the fourth resistor is connected to an input end of the voltage stabilizing chip, the other end of the fourth resistor is grounded, one end of the fifth resistor is connected between the sixth resistor and the third resistor, the other end of the fifth resistor is connected to an output end of the voltage stabilizing chip and is connected to the voltage regulating unit, one end of the second capacitor is connected between the sixth resistor and the third resistor, the other end of the second capacitor is connected with the input end of the voltage stabilizing chip, one end of the third capacitor is connected between the sixth resistor and the third resistor, and the other end of the third capacitor is grounded.
4. The signal conversion circuit according to claim 3, wherein the isolation conversion unit includes a seventh resistor, a twenty-first resistor, and an optocoupler, an anode of a light emitting diode of the optocoupler is connected to the second power supply, a cathode of the light emitting diode is connected to one end of the twenty-first resistor, the other end of the twenty-first resistor is used for inputting the PWM signal, an emitter of a photo-transistor of the optocoupler is grounded, a collector of the photo-transistor is connected to one end of the seventh resistor, and the other end of the seventh resistor is connected to the other end of the sixth resistor and the voltage adjustment unit.
5. The signal conversion circuit according to claim 4, wherein the voltage adjustment unit includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, and an adjustable resistor, one end of the eighth resistor is connected between the sixth resistor and the seventh resistor, the other end of the eighth resistor is connected with the voltage follower unit, one end of the ninth resistor is connected between the eighth resistor and the voltage follower unit, the other end of the ninth resistor is connected with one end of the tenth resistor, the other end of the tenth resistor is grounded, one end of the eleventh resistor is grounded, the other end of the eleventh resistor is connected with one end of the adjustable resistor, the other end of the adjustable resistor is connected between the ninth resistor and the tenth resistor, one end of the twelfth resistor is connected between the eleventh resistor and the adjustable resistor, the other end of the twelfth resistor is connected with the fifth resistor.
6. The signal converting circuit according to claim 5, wherein the voltage following unit comprises a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a third diode and an operational amplifier, a power supply terminal of the operational amplifier is connected to the other end of the second resistor, a ground terminal of the operational amplifier is grounded, an output terminal of the operational amplifier is connected to an anode of the third diode, a cathode of the third diode is used for being connected to the controller, the seventeenth resistor is connected to the third diode in parallel, a non-inverting input terminal of the operational discharger is connected to one end of the sixth capacitor, the other end of the sixth capacitor is grounded and connected to one end of the fourth capacitor, and the other end of the fourth capacitor is connected to one end of the fourteenth resistor, the other end of the fourteenth resistor is used for being connected with the controller, one end of the sixteenth resistor is connected between the non-inverting input end of the operational amplifier and the sixth capacitor, the other end of the sixteenth resistor is connected with one end of the fifth capacitor, the other end of the fifth capacitor is connected with one end of the fifteenth resistor, the other end of the fifteenth resistor is used for being connected with the controller, one end of the thirteenth resistor is connected between the eighth resistor and the ninth resistor, and the other end of the thirteenth resistor is connected between the fourth capacitor and the fourteenth resistor and between the sixteenth resistor and the fifth capacitor.
7. The signal conversion circuit according to any one of claims 1 to 6, further comprising an over-temperature protection unit, wherein one end of the over-temperature protection unit is connected to the power supply unit, and the other end of the over-temperature protection unit is connected to the output end of the voltage follower unit and the voltage adjustment unit, and is configured to pull down the voltage of the output signal or the control voltage signal to reduce the temperature when the temperature is over-temperature.
8. The signal converting circuit according to claim 7, wherein the over-temperature protection unit comprises an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a thermistor, a seventh capacitor, a second voltage regulator tube, and a triode, one end of the thermistor is connected between the positive electrode of the first diode and the first power supply, the other end of the thermistor is connected with the negative electrode of the second voltage regulator tube, the positive electrode of the second voltage regulator tube is connected with the base electrode of the triode, the collector electrode of the triode is connected with one end of the eighteenth resistor, the other end of the eighteenth resistor is connected between the fourteenth resistor and the controller, the emitter electrode of the triode is grounded, one end of the nineteenth resistor is connected between the base electrode of the triode and the positive electrode of the second voltage regulator tube, and the other end of the nineteenth resistor is grounded, the seventh capacitor is connected in parallel with the nineteenth resistor, one end of the twentieth resistor is connected between the negative electrode of the second voltage regulator tube and the thermistor, and the other end of the twentieth resistor is grounded.
9. An LED driving power supply, characterized by comprising a signal conversion circuit according to any one of claims 1 to 8.
10. An LED lamp comprising an LED driving power supply according to claim 9.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010156534.9A CN111194110A (en) | 2020-03-09 | 2020-03-09 | Signal conversion circuit, LED drive power supply and LED lamp |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010156534.9A CN111194110A (en) | 2020-03-09 | 2020-03-09 | Signal conversion circuit, LED drive power supply and LED lamp |
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| CN111194110A true CN111194110A (en) | 2020-05-22 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112638000A (en) * | 2020-12-09 | 2021-04-09 | 成都极米科技股份有限公司 | Voltage regulating circuit and light regulating circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112638000A (en) * | 2020-12-09 | 2021-04-09 | 成都极米科技股份有限公司 | Voltage regulating circuit and light regulating circuit |
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