LED driving overvoltage protection circuit

Abstract

The utility model discloses an LED driving overvoltage protection circuit, which relates to the technical field of LED driving protection, and comprises a power supply module used for supplying power; the power supply control module is used for electric energy transmission and power-off protection; the LED driving module is used for sampling current, receiving a feedback signal and performing constant-current driving on the LED module; the LED module is used for illumination work; the voltage sampling module is used for carrying out voltage sampling on the LED module and outputting a feedback signal; the feedback detection module is used for transmitting the feedback signal to the LED driving module and detecting whether the LED driving module receives the feedback signal or not; the overvoltage judgment module is used for overvoltage detection; and the abnormity display module is used for performing overvoltage abnormity display. The LED driving overvoltage protection circuit can improve the LED driving safety and the reliability of LED driving overvoltage detection.

Description

TECHNICAL FIELD

[0001] The utility model relates to LED drive protection technical field, concretely is a kind of LED drive overvoltage protection circuit. BACKGROUND

[0002] With the popularization of LED lighting, LED lamp has been widely used in various occasions. In order to ensure the safety and reliability of application, the mainstream constant current LED drive chip in the market currently integrates multiple protection functions, such as overcurrent protection, overvoltage protection, over-temperature protection, etc., but cannot automatically determine whether the overvoltage protection of constant current LED drive chip is normal, and some constant current LED drive chips cannot perform overvoltage protection, resulting in reduced LED drive safety, and thus need to be improved. SUMMARY

[0003] The utility model embodiment provides a kind of LED drive overvoltage protection circuit to solve the problems raised in the above background technique.

[0004] To achieve the above object, the utility model provides the following technical scheme:

[0005] A kind of LED drive overvoltage protection circuit, comprising: power module, power supply control module, LED drive module, LED module, voltage sampling module, feedback detection module, overvoltage judging module and abnormal display module;

[0006] Power module is used to connect direct current energy and carries out filtering treatment to direct current energy;

[0007] Power supply control module, with the power module, overvoltage judging module, feedback detection module, LED drive module and LED module are used to transmit direct current energy to LED drive module and LED module, when receiving the first control signal output by overvoltage judging module and the second control signal output by feedback detection module, stop transmission direct current energy;

[0008] LED drive module, with the LED module and feedback detection module connection, is used to carry out current sampling to LED module and receive feedback signal transmitted by feedback detection module, and output drive signal, carry out constant current regulation processing to the direct current energy of input and output first electric energy;

[0009] LED module is used to receive first electric energy and carry out lighting work;

[0010] Voltage sampling module, with the LED module connection, is used to carry out voltage sampling to the first electric energy received by LED module and output feedback signal;

[0011] The feedback detection module is connected with the voltage sampling module, and is configured to transmit a feedback signal to the LED driving module, and output a second control signal when the feedback signal is not transmitted.

[0012] The overvoltage judgment module is connected with the voltage sampling module, and is configured to set an overvoltage threshold value and output a first control signal when the voltage of the feedback signal is greater than the overvoltage threshold value.

[0013] The abnormality display module is connected with the overvoltage judgment module, and is configured to perform overvoltage abnormality display when the first control signal and the driving signal are received.

[0014] As a further scheme of the utility model: the LED driving module includes a first resistor, a second capacitor, a third capacitor, a first driver, a first power tube, a first diode and a second resistor; the LED module includes a first inductor and an LED module group;

[0015] Preferably, the first end of the first resistor is connected with the power supply control module, the cathode of the first diode and the first end of the LED module group, the second end of the first resistor is connected with the VDD end and the DIM end of the first driver and grounded through the second capacitor, the TOFF end of the first driver is grounded through the third capacitor, the DRV end of the first driver is connected with the gate of the first power tube, the drain of the first power tube is connected with the cathode of the first diode and the first end of the first inductor, the second end of the first inductor is connected with the second end of the LED module group, the source of the first power tube is connected with the CS end of the first driver and connected with the GND end and the ground end of the first driver through the second resistor, and the FB end of the first driver is connected with the feedback detection module.

[0016] As a further scheme of the utility model: the feedback detection module includes a first optocoupler, a seventh resistor and a second power supply;

[0017] Preferably, the first end of the first optocoupler is connected with the voltage sampling module, the second end of the first optocoupler is connected with the FB end of the first driver, the third end of the first optocoupler is connected with the first end of the seventh resistor and the power supply control module, the second end of the seventh resistor is connected with the second power supply, and the fourth end of the first optocoupler is grounded.

[0018] As a further scheme of the utility model: the voltage sampling module includes a second inductor, a third resistor, a fourth resistor and a second diode; the overvoltage judgment module includes a sixth resistor, a fifth resistor, a first power supply, a first potentiometer and a first comparator;

[0019] Preferably, the first end of the second inductor is connected with one end of the fourth resistor, the cathode of the second diode, the first end of the first optocoupler and the non-inverting terminal of the first comparator through the third resistor, the second end of the second inductor is connected with the other end of the fourth resistor, the anode of the second diode, one end of the sixth resistor and the ground terminal, the other end of the sixth resistor is connected with one end of the first potentiometer, the other end of the first potentiometer is connected with the first power supply through the fifth resistor, the wiper terminal of the first potentiometer is connected with the inverting terminal of the first comparator, and the output terminal of the first comparator is connected with the power supply control module and the abnormality display module.

[0020] As a further scheme of the utility model: the abnormality display module includes a third diode, a first logic chip, a ninth resistor and a first indicator lamp;

[0021] Preferably, the anode of the third diode is connected with the gate of the first power transistor, the cathode of the third diode is connected with the A terminal of the first logic chip, the B terminal of the first logic chip is connected with the output terminal of the first comparator, the Y terminal of the first logic chip is connected with the anode of the first indicator lamp through the ninth resistor, and the cathode of the first indicator lamp is grounded.

[0022] As a further scheme of the utility model: the power supply control module includes an eighth resistor, a second power transistor, a first switch tube and a second logic chip; the power supply module includes a power supply interface and a first capacitor;

[0023] Preferably, the drain of the second power transistor is connected with the first end of the power supply interface and one end of the first capacitor and connected with the gate of the second power transistor and the collector of the first switch tube through the eighth resistor, the source of the second power transistor is connected with the first end of the first resistor and the first end of the LED module, the base of the first switch tube is connected with the Y terminal of the second logic chip, the A terminal and the B terminal of the second logic chip are connected with the output terminal of the first comparator and the first end of the seventh resistor respectively, and the emitter of the first switch tube is connected with the second end of the power supply interface, the other end of the first capacitor and the ground terminal.

[0024] Compared with the prior art, the utility model has the beneficial effects that: the LED drive overvoltage protection circuit can detect the overvoltage of the LED module through the voltage sampling module and the overvoltage judgment module when the LED drive module cannot detect the overvoltage of the LED module, and the power supply control module is controlled to be powered off when overvoltage occurs, the LED drive module can detect the overvoltage of the LED module, whether the LED drive module normally judges the overvoltage is judged by the voltage sampling module and the overvoltage judgment module, and the abnormality display module displays the abnormality if overvoltage detection is abnormal, thereby improving the LED drive safety and the reliability of the overvoltage detection of the LED drive. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 A principle block diagram of an LED drive overvoltage protection circuit is provided for the embodiment of the present application.

[0027] Figure 2 A circuit diagram of an LED drive overvoltage protection circuit is provided for the embodiment of the present application.

[0028] Figure 3 A connection circuit diagram of a power supply control module is provided for the embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0030] In one embodiment, referring to Figure 1 , an LED drive overvoltage protection circuit comprises: a power supply module 1, a power supply control module 2, an LED drive module 3, an LED module 4, a voltage sampling module 5, a feedback detection module 6, an overvoltage judgment module 7 and an abnormality display module 8.

[0031] Specifically, the power supply module 1 is configured to connect to direct current energy and perform filtering processing on the direct current energy.

[0032] The power supply control module 2 is configured to transmit the direct current energy to the LED drive module 3 and the LED module 4, and stop transmitting the direct current energy when receiving a first control signal output by the overvoltage judgment module 7 and a second control signal output by the feedback detection module 6.

[0033] The LED drive module 3 is connected to the LED module 4 and the feedback detection module 6, and is configured to perform current sampling on the LED module 4 and receive a feedback signal transmitted by the feedback detection module 6, and output a drive signal, perform constant current adjustment processing on the input direct current energy and output a first electric energy.

[0034] LED module 4, for receiving the first electric energy and lighting work;

[0035] Voltage sampling module 5, connected with the LED module 4, for voltage sampling the first electric energy received by the LED module 4 and outputting a feedback signal;

[0036] Feedback detection module 6, connected with the voltage sampling module 5, for transmitting the feedback signal to the LED driving module 3 and outputting a second control signal when no feedback signal is transmitted;

[0037] Overvoltage judgment module 7, connected with the voltage sampling module 5, for setting an overvoltage threshold and outputting a first control signal when the voltage of the feedback signal is greater than the overvoltage threshold;

[0038] Abnormal display module 8, connected with the overvoltage judgment module 7, for overvoltage abnormal display when receiving the first control signal and the driving signal.

[0039] In a specific embodiment, the power module 1 can adopt a power supply circuit composed of a power supply interface and a capacitor to access the direct current electric energy and filter; the power supply control module 2 can adopt a power supply control circuit composed of a field effect transistor, a triode, a logic chip, etc., which can control the transmission of electric energy and perform power-off protection when receiving the signals output by the voltage sampling module 5 and the feedback detection module 6; the LED driving module 3 can adopt an LED driving circuit composed of a constant current driver, a field effect transistor, a capacitor, a diode, etc., which can perform constant current regulation on the input electric energy; the LED module 4 can adopt an LED circuit composed of an LED module and an inductor, which can perform lighting work; the voltage sampling module 5 can adopt a voltage sampling circuit composed of an inductor and a resistor, which can perform voltage sampling; the feedback detection module 6 can adopt a feedback detection circuit composed of an optoelectronic coupler, a resistor, and a constant voltage source, which can transmit the signal sampled by the voltage sampling module 5 to the LED driving module 3 and judge whether the LED driving module 3 receives the feedback signal; the overvoltage judgment module 7 can adopt an overvoltage judgment circuit composed of a resistor, a comparator, and a constant voltage source, which sets an overvoltage threshold and outputs a signal in high level state when the sampled signal is greater than the overvoltage threshold; the abnormal display module 8 can adopt an abnormal display circuit composed of a diode, a logic chip, and an indicator light, which can perform abnormal display when receiving the signal in high level state output by the overvoltage judgment module 7 and receiving the driving signal output by the LED driving module 3.

[0040] In another embodiment, please refer to Figure 1 , Figure 2 and Figure 3, the LED driving module 3 comprises a first resistor R1, a second capacitor C2, a third capacitor C3, a first driver IC1, a first power tube Q1, a first diode D1 and a second resistor R2; the LED module 4 comprises a first inductor L1 and an LED module;

[0041] Specifically, a first end of the first resistor R1 is connected with the power supply control module 2, a cathode of the first diode D1 and a first end of the LED module, a second end of the first resistor R1 is connected with a VDD end and a DIM end of the first driver IC1 and grounded through the second capacitor C2, a TOFF end of the first driver IC1 is grounded through the third capacitor C3, a DRV end of the first driver IC1 is connected with a gate of the first power tube Q1, a drain of the first power tube Q1 is connected with a cathode of the first diode D1 and a first end of the first inductor L1, a second end of the first inductor L1 is connected with a second end of the LED module, a source of the first power tube Q1 is connected with a CS end of the first driver IC1 and a GND end and a ground end of the first driver IC1 through the second resistor R2, and a FB end of the first driver IC1 is connected with the feedback detection module 6.

[0042] In specific embodiments, the first driver IC1 can be selected from OC5021B driver and R8021 driver, but is not limited to OC5021B driver and R8021 driver, wherein the OC5021B driver does not perform voltage sampling, and the R8021 driver can perform voltage sampling; the first power tube Q1 can be selected from N-channel field effect tube; and the second resistor R2 performs current sampling.

[0043] Further, the feedback detection module 6 comprises a first optocoupler IC2, a seventh resistor R7 and a second power supply VCC2.

[0044] Specifically, a first end of the first optocoupler IC2 is connected with the voltage sampling module 5, a second end of the first optocoupler IC2 is connected with a FB end of the first driver IC1, a third end of the first optocoupler IC2 is connected with a first end of the seventh resistor R7 and the power supply control module 2, a second end of the seventh resistor R7 is connected with the second power supply VCC2, and a fourth end of the first optocoupler IC2 is grounded.

[0045] In specific embodiments, the first optocoupler IC2 can be selected from PC817 photoelectric coupler.

[0046] Further, the voltage sampling module 5 comprises a second inductor L2, a third resistor R3, a fourth resistor R4 and a second diode D2; the overvoltage judgment module 7 comprises a sixth resistor R6, a fifth resistor R5, a first power supply VCC1, a first potentiometer RP1 and a first comparator A1.

[0047] Specifically, the first end of the second inductor L2 is connected with one end of the fourth resistor R4, the cathode of the second diode D2, the first end of the first optocoupler IC2 and the non-inverting terminal of the first comparator A1 through the third resistor R3, the second end of the second inductor L2 is connected with the other end of the fourth resistor R4, the anode of the second diode D2, one end of the sixth resistor R6 and the ground terminal, the other end of the sixth resistor R6 is connected with one end of the first potentiometer RP1, the other end of the first potentiometer RP1 is connected with the first power supply VCC1 through the fifth resistor R5, the wiper terminal of the first potentiometer RP1 is connected with the inverting terminal of the first comparator A1, and the output terminal of the first comparator A1 is connected with the power supply control module 2 and the abnormality display module 8.

[0048] In specific embodiments, the second inductor L2 and the first inductor L1 are wound on the same magnetic core, the third resistor R3 and the fourth resistor R4 are used for voltage division sampling, the first power supply VCC1 cooperates with the fifth resistor R5, the first potentiometer RP1 and the sixth resistor R6 to set the overvoltage threshold, and the first comparator A1 can be an LM358 comparator.

[0049] Further, the abnormality display module 8 includes a third diode D3, a first logic chip J1, a ninth resistor R9 and a first indicator lamp LED1.

[0050] Specifically, the anode of the third diode D3 is connected with the gate of the first power transistor Q1, the cathode of the third diode D3 is connected with the A terminal of the first logic chip J1, the B terminal of the first logic chip J1 is connected with the output terminal of the first comparator A1, the Y terminal of the first logic chip J1 is connected with the anode of the first indicator lamp LED1 through the ninth resistor R9, and the cathode of the first indicator lamp LED1 is grounded.

[0051] In specific embodiments, the first logic chip J1 can be an AND gate chip, and the first indicator lamp LED1 can be an LED.

[0052] Further, the power supply control module 2 includes an eighth resistor R8, a second power transistor Q2, a first switch transistor V1 and a second logic chip J2, and the power supply module 1 includes a power supply interface and a first capacitor C1.

[0053] Specifically, the drain of the second power transistor Q2 is connected with the first end of the power supply interface and one end of the first capacitor C1, and is connected with the gate of the second power transistor Q2 and the collector of the first switch transistor V1 through the eighth resistor R8, the source of the second power transistor Q2 is connected with the first end of the first resistor R1 and the first end of the LED module, the base of the first switch transistor V1 is connected with the Y terminal of the second logic chip J2, the A terminal and the B terminal of the second logic chip J2 are respectively connected with the output terminal of the first comparator A1 and the first end of the seventh resistor R7, and the emitter of the first switch transistor V1 is connected with the second end of the power supply interface, the other end of the first capacitor C1 and the ground terminal.

[0054] In specific embodiments, the second power tube Q2 can be an N-channel field effect tube, the first switch tube V1 can be an NPN type triode, and the second logic chip J2 can be an AND gate chip.

[0055] In the LED drive overvoltage protection circuit, DC power is accessed through the power interface, the first capacitor C1 performs filtering, the second power tube Q2 performs power transmission, the first driver IC1 receives the current signal sampled by the second resistor R2, and if the first driver IC1 used has voltage feedback, i.e., there is an FB end, voltage sampling will be performed, and the first resistor R1, the second capacitor C2, the third capacitor C3, and the first diode D1 output a drive signal and drive the on-off state of the first power tube Q1 to provide constant current and voltage stabilization for the LED module. At this time, the first optocoupler IC2 is turned on, the second inductor L2, the third resistor R3, the fourth resistor R4, and the second diode D2 sample the voltage signal and transmit it to the FB end of the first driver IC1. At the same time, when the sampled voltage signal is greater than the overvoltage threshold set by the first power supply VCC1, the fifth resistor R5, the first potentiometer RP1, and the sixth resistor R6, the first comparator A1 outputs a high level. If the DRV end of the first driver IC1 is still driving the first power tube Q1 to work at this time, the first indicator LED1 will be turned on by the first logic chip J1 to display the overvoltage detection abnormality. If the first driver IC1 used does not have voltage feedback, i.e., there is no FB end, the first optocoupler IC2 will be cut off, and the second power supply VCC2 will trigger the B end of the second logic chip J2 to become high through the seventh resistor R7. If the sampled voltage signal is greater than the overvoltage threshold at this time, the first comparator A1 outputs a high level, and the Y end of the second logic chip J2 will trigger the first switch tube V1 to turn on, and the second power tube Q2 will be cut off to perform power-off protection.

[0056] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and the present application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all aspects as illustrative and not restrictive, and the scope of the present application is defined by the appended claims rather than the foregoing description, and it is intended to encompass all changes falling within the meaning and range of equivalents of the claims. Any reference signs in the claims should not be considered as limiting the claims involved.

[0057] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature or implementation described herein. The specification can include implicit combinations of explicitly mentioned features and / or implicit combinations of implicitly mentioned features. Such combinations are also expressly included within the scope of the specification and an embodiment.

Claims

1. An LED driving overvoltage protection circuit, characterized in that, the LED driving overvoltage protection circuit comprises a power supply module, a power supply control module, an LED driving module, an LED module, a voltage sampling module, a feedback detection module, an overvoltage judgment module and an abnormality display module; the power supply module is configured to access and filter direct current power; the power supply control module is connected with the power supply module, the overvoltage judgment module, the feedback detection module, the LED driving module and the LED module, and is configured to transmit the direct current power to the LED driving module and the LED module, and stop transmitting the direct current power when receiving a first control signal output by the overvoltage judgment module and a second control signal output by the feedback detection module; the LED driving module is connected with the LED module and the feedback detection module, and is configured to sample current of the LED module, receive a feedback signal transmitted by the feedback detection module, and output a driving signal, and perform constant current regulation on input direct current power and output first power; the LED module is configured to receive the first power and perform lighting work; the voltage sampling module is connected with the LED module, and is configured to sample voltage of the first power received by the LED module and output a feedback signal; the feedback detection module is connected with the voltage sampling module, and is configured to transmit the feedback signal to the LED driving module, and output the second control signal when the feedback signal is not transmitted; the overvoltage judgment module is connected with the voltage sampling module, and is configured to set an overvoltage threshold, and output the first control signal when voltage of the feedback signal is greater than the overvoltage threshold; the abnormality display module is connected with the overvoltage judgment module, and is configured to perform overvoltage abnormality display when receiving the first control signal and the driving signal.

2. The LED driving overvoltage protection circuit according to claim 1, characterized in that, the LED driving module comprises a first resistor, a second capacitor, a third capacitor, a first driver, a first power tube, a first diode and a second resistor; and the LED module comprises a first inductor and an LED module group; a first end of the first resistor is connected with the power supply control module, a cathode of the first diode and a first end of the LED module group, a second end of the first resistor is connected with a VDD end and a DIM end of the first driver and grounded through the second capacitor, a TOFF end of the first driver is grounded through the third capacitor, a DRV end of the first driver is connected with a gate of the first power tube, a drain of the first power tube is connected with the cathode of the first diode and a first end of the first inductor, a second end of the first inductor is connected with a second end of the LED module group, a source of the first power tube is connected with a CS end of the first driver and connected with a GND end and a ground end of the first driver through the second resistor, and a FB end of the first driver is connected with the feedback detection module.

3. The LED driving overvoltage protection circuit according to claim 2, characterized in that, the feedback detection module comprises a first optocoupler, a seventh resistor and a second power supply; a first end of the first optocoupler is connected with the voltage sampling module, a second end of the first optocoupler is connected with the FB end of the first driver, a third end of the first optocoupler is connected with a first end of the seventh resistor and the power supply control module, a second end of the seventh resistor is connected with the second power supply, and a fourth end of the first optocoupler is grounded.

4. The LED driving overvoltage protection circuit according to claim 3, characterized in that, The voltage sampling module comprises a second inductor, a third resistor, a fourth resistor and a second diode; the overvoltage judging module comprises a sixth resistor, a fifth resistor, a first power supply, a first potentiometer and a first comparator; The first end of the second inductor is connected to one end of the fourth resistor, the cathode of the second diode, the first end of the first optocoupler and the non-inverting terminal of the first comparator through the third resistor; the second end of the second inductor is connected to the other end of the fourth resistor, the anode of the second diode, one end of the sixth resistor and the ground terminal; the other end of the sixth resistor is connected to one end of the first potentiometer; the other end of the first potentiometer is connected to the first power supply through the fifth resistor; the wiper terminal of the first potentiometer is connected to the inverting terminal of the first comparator; the output terminal of the first comparator is connected to the power supply control module and the abnormality display module.

5. The LED driving overvoltage protection circuit according to claim 4, characterized in that, The abnormality display module comprises a third diode, a first logic chip, a ninth resistor and a first indicator lamp; The anode of the third diode is connected to the gate of the first power transistor; the cathode of the third diode is connected to the A terminal of the first logic chip; the B terminal of the first logic chip is connected to the output terminal of the first comparator; the Y terminal of the first logic chip is connected to the anode of the first indicator lamp through the ninth resistor; the cathode of the first indicator lamp is grounded.

6. The LED driving overvoltage protection circuit according to claim 4, characterized in that, The power supply control module comprises an eighth resistor, a second power transistor, a first switch transistor and a second logic chip; the power supply module comprises a power supply interface and a first capacitor; The drain of the second power transistor is connected to the first end of the power supply interface and one end of the first capacitor and is connected to the gate of the second power transistor and the collector of the first switch transistor through the eighth resistor; the source of the second power transistor is connected to the first end of the first resistor and the first end of the LED module; the base of the first switch transistor is connected to the Y terminal of the second logic chip; the A terminal and the B terminal of the second logic chip are connected to the output terminal of the first comparator and the first end of the seventh resistor, respectively; the emitter of the first switch transistor is connected to the second end of the power supply interface, the other end of the first capacitor and the ground terminal.

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