LED detection device

Abstract

The present invention discloses an LED detection device, comprising: a power supply circuit, an MCU control circuit, a plurality of short-circuit diagnostic circuits and a plurality of open-circuit diagnostic circuits; the power supply circuit is connected with the short-circuit diagnostic circuit, the open-circuit diagnostic circuit and the MCU control circuit, and is used to provide power for the short-circuit diagnostic circuit, the open-circuit diagnostic circuit and the MCU control circuit; each LED to be tested is connected with the short-circuit diagnostic circuit and the open-circuit diagnostic circuit; the MCU control circuit is connected in series with a plurality of the short-circuit diagnostic circuits and the open-circuit diagnostic circuits, and is used to obtain a diagnostic voltage after the short-circuit diagnostic circuit and the open-circuit diagnostic circuit are connected in series, and the MCU control circuit determines whether the LED to be tested is short-circuited or short-circuited according to the diagnostic voltage. The present invention is connected with a short-circuit diagnostic circuit and an open-circuit diagnostic circuit for each LED to be tested.

Description

Technical Field

[0001] The invention belongs to the technical field of LED manufacturing, and in particular relates to an LED detection device. Background Art

[0002] As a high-brightness, efficient and clean light source, LED has been widely used in all walks of life. With the advancement of science and technology, all industries are moving towards intelligence and technology, and the application of LED is no exception. With the current intelligent application of LED, the working status of each LED has become particularly important for the later analysis of the product.

[0003] Currently, LED open-circuit and short-circuit detection circuits are all aimed at detecting an open circuit or short circuit in a string of LEDs, and cannot provide feedback on the specific location of the faulty LED. In order to find the faulty LED in a string of LEDs, additional detection is required, resulting in low efficiency. Summary of the invention

[0004] In order to overcome the above technical defects, the present invention provides an LED detection device, which can detect each LED.

[0005] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0006] An LED detection device comprises: a power supply circuit, an MCU control circuit, a plurality of short-circuit diagnosis circuits and a plurality of open-circuit diagnosis circuits;

[0007] The power supply circuit is connected to the short-circuit diagnosis circuit, the open-circuit diagnosis circuit and the MCU control circuit, and is used to provide power to the short-circuit diagnosis circuit, the open-circuit diagnosis circuit and the MCU control circuit;

[0008] Each LED to be tested is connected to the short-circuit diagnostic circuit and the open-circuit diagnostic circuit;

[0009] The MCU control circuit is connected in series with several short-circuit diagnostic circuits and several open-circuit diagnostic circuits to obtain the diagnostic voltage after the short-circuit diagnostic circuit and the open-circuit diagnostic circuit are connected in series. The MCU control circuit determines whether the LED to be tested is short-circuited or short-circuited based on the diagnostic voltage.

[0010] As a further improvement of the present invention, the power supply circuit includes: a filtering and anti-reverse circuit and a voltage stabilizing circuit;

[0011] The input end of the filtering and anti-reverse circuit is connected to a DC power supply, the output end of the filtering and anti-reverse circuit is connected to the input end of the voltage stabilizing circuit and the LED to be tested, and the output end of the voltage stabilizing chip is connected to the open circuit diagnosis circuit, the short circuit diagnosis circuit and the MCU control circuit.

[0012] As a further improvement of the present invention, the voltage stabilizing circuit includes: a voltage stabilizing chip, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, the first end of the voltage stabilizing chip is the input end of the voltage stabilizing circuit, the first end of the voltage stabilizing chip is connected to the output end of the filtering and anti-reverse circuit, the first end of the voltage stabilizing chip is grounded through the first capacitor, the first end of the voltage stabilizing chip is grounded through the second capacitor, the second end, the third end and the fourth end of the voltage stabilizing chip are grounded, the fifth end of the voltage stabilizing chip is grounded through the third capacitor, the fifth end of the voltage stabilizing chip is grounded through the fourth capacitor, and the fifth end of the voltage stabilizing chip is the output end of the voltage stabilizing circuit.

[0013] As a further improvement of the present invention, the present invention further includes a voltage-dividing resistor, and the output end of the voltage-stabilizing circuit is connected to the short-circuit diagnostic circuit, the open-circuit diagnostic circuit and the MCU control circuit through the voltage-dividing resistor.

[0014] As a further improvement of the present invention, the short circuit diagnosis circuit comprises: a first triode, a second triode, a third triode, a first resistor, a second resistor, a third resistor and a fourth resistor;

[0015] The filtering and anti-reverse circuit is connected to the base of the first transistor through the forward-conducting LED to be tested, the filtering and anti-reverse circuit is connected to the emitter of the first transistor through the first resistor, the collector of the first transistor is grounded through the second resistor, the collector of the first transistor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the base of the second transistor is connected to the output end of the voltage stabilizing circuit through the third resistor, the collector of the second transistor is connected to the base of the third transistor, the emitter of the third transistor is grounded, and the collector of the third transistor is connected to the output end of the voltage stabilizing circuit through the fourth resistor and the voltage dividing resistor.

[0016] As a further improvement of the present invention, the open circuit diagnostic circuit includes: a fourth transistor, a fifth transistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor;

[0017] The filtering and anti-reverse circuit is connected to the base of the fourth transistor through the forward-conducting LED to be tested and the fifth resistor, the base of the fourth transistor is grounded through the sixth resistor, the collector of the fourth transistor is connected to the output end of the voltage stabilizing circuit through the seventh resistor, the collector of the fourth transistor is connected to the fifth transistor, the emitter of the fifth transistor is grounded, and the collector of the fifth transistor is connected to the collector of the third transistor through the eighth resistor.

[0018] As a further improvement of the present invention, the first transistor is a PNP transistor, and the second transistor, the third transistor, the fourth transistor and the fifth transistor are all NPN transistors.

[0019] As a further improvement of the present invention, the present invention also includes a power open circuit diagnostic circuit connected between the voltage divider resistor and the short circuit diagnostic circuit, and the MCU control circuit is also connected to the power open circuit diagnostic circuit to obtain a third diagnostic voltage of the power open circuit diagnostic circuit and determine whether the power circuit is open based on the diagnostic voltage.

[0020] As a further improvement of the present invention, the power open circuit diagnostic circuit comprises: a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a sixth transistor and a seventh transistor;

[0021] The output end of the filtering and anti-reverse circuit is grounded through the ninth resistor and the tenth resistor, the base of the sixth transistor is grounded through the tenth resistor, the emitter of the sixth transistor is grounded, the collector of the sixth transistor is connected to the output end of the voltage stabilizing circuit through the eleventh resistor, the base of the seventh transistor is connected to the collector of the sixth transistor, the emitter of the seventh transistor is grounded, and the collector of the seventh transistor is connected to the output end of the voltage stabilizing circuit through the twelfth resistor and the voltage dividing resistor.

[0022] As a further improvement of the present invention, the present invention further includes: a power device, the filtering anti-reverse circuit is connected to ground through the LED to be tested which is forward-conducted, and the power device.

[0023] Compared with the prior art, the present invention has the following beneficial effects: a short-circuit diagnostic circuit and an open-circuit diagnostic circuit are connected to each LED to be tested, and a diagnostic voltage is obtained from the short-circuit diagnostic circuit and the open-circuit diagnostic circuit through an MCU control circuit. When in use, the LEDs to be tested are connected in series, and the MCU control circuit, the short-circuit diagnostic circuit and the open-circuit diagnostic circuit are connected in series, so that when each LED to be tested is open-circuited or short-circuited, the diagnostic voltage obtained by the MCU control circuit is also different, and according to the value of the diagnostic voltage, the faulty LED to be tested can be accurately located. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 This is a schematic diagram of the overall structure of the LED detection device described in Example 1;

[0026] Figure 2 It is a partial structural schematic diagram of the LED detection device described in Example 1;

[0027] Figure 3 It is a structural schematic diagram of the MCU control circuit and the voltage stabilizing circuit described in Example 1;

[0028] Figure 4 It is a structural schematic diagram of the filtering and anti-reverse circuit described in Example 1.

[0029] Marking description: 1. Power supply circuit; 11. Filter and anti-reverse circuit; 12. Voltage stabilization circuit; 2. MCU control circuit; 3. Short circuit diagnosis circuit; 4. Open circuit diagnosis circuit; 5. Power supply open circuit diagnosis circuit; 6. Power device. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0031] Embodiment 1

[0032] The present embodiment provides an LED detection device, including: a power supply circuit 1, an MCU control circuit 2, a plurality of short-circuit diagnostic circuits 3 and a plurality of open-circuit diagnostic circuits 4; the power supply circuit 1 is connected to the short-circuit diagnostic circuit 3, the open-circuit diagnostic circuit 4 and the MCU control circuit 2, and is used to provide power for the short-circuit diagnostic circuit 3, the open-circuit diagnostic circuit 4 and the MCU control circuit 2; each LED to be tested is connected to a short-circuit diagnostic circuit connection and an open-circuit diagnostic circuit; the MCU control circuit 2 is connected in series with the plurality of short-circuit diagnostic circuits 3 and the plurality of open-circuit diagnostic circuits 4, and is used to obtain a diagnostic voltage after the short-circuit diagnostic circuit 3 and the open-circuit diagnostic circuit 4 are connected in series, and the MCU control circuit 2 determines whether the LED to be tested is short-circuited or open-circuited according to the diagnostic voltage.

[0033] Specifically, the MCU control circuit 2 is connected in series with the short-circuit diagnostic circuit 3 and the open-circuit diagnostic circuit 4. The number of short-circuit diagnostic circuits 3 and open-circuit diagnostic circuits 4 can be set according to the actual number of LEDs to be tested. The LED to be tested 1, the LED to be tested 2, the LED to be tested 3... are connected to different short-circuit diagnostic circuits 3 and open-circuit diagnostic circuits 4 in sequence.

[0034] In order to achieve stable input of power supply, the power supply circuit 1 includes: a filtering anti-reverse circuit 11 and a voltage stabilizing circuit 12; the input end of the filtering anti-reverse circuit 11 is connected to the power supply, the output end of the filtering anti-reverse circuit 11 is connected to the input end of the voltage stabilizing circuit 12 and the LED to be tested, and the output end of the voltage stabilizing circuit 12 is connected to the open circuit diagnosis circuit 4, the short circuit diagnosis circuit 3 and the MCU control circuit 2. Since the operating voltage of the MCU control circuit 2 in this embodiment is 5V, the voltage stabilizing circuit 11 adopts a voltage stabilizing circuit with an output of 5V.

[0035] Specifically, the voltage stabilizing circuit 12 includes: a voltage stabilizing chip U1, a first capacitor C1, a second capacitor C2, a third capacitor C3 and a fourth capacitor C4. The first end of the voltage stabilizing chip U1 is the input end of the voltage stabilizing circuit 12, the first end of the voltage stabilizing chip U1 is connected to the output end of the filtering and anti-reverse circuit 11, the first end of the voltage stabilizing chip U1 is grounded through the first capacitor C1, the first end of the voltage stabilizing chip U1 is grounded through the second capacitor C2, the second end, the third end and the fourth end of the voltage stabilizing chip U1 are grounded, the fifth end of the voltage stabilizing chip U1 is grounded through the third capacitor C3, the fifth end of the voltage stabilizing chip U1 is grounded through the fourth capacitor C4, and the fifth end of the voltage stabilizing chip U1 is the output end of the voltage stabilizing circuit 12.

[0036] Furthermore, the present embodiment further includes a voltage-dividing resistor R0 , and the output end of the voltage-stabilizing circuit 12 is connected to the short-circuit diagnosis circuit 3 , the open-circuit diagnosis circuit 4 and the AD Detect port of the MCU chip U2 in the MCU control circuit 2 through the voltage-dividing resistor R0 .

[0037] Specifically, the short circuit diagnosis circuit 3 includes: a first transistor TR1, a second transistor TR2, a third transistor TR3, a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4; the filter anti-reverse circuit 11 is connected to the base of the first transistor TR3 through the forward-conducting LED to be tested, the filter anti-reverse circuit 11 is connected to the emitter of the first transistor TR1 through the first resistor R1, the collector of the first transistor TR1 is grounded through the second resistor R2, the collector of the first transistor TR1 is connected to the base of the second transistor TR2, the emitter of the second transistor TR2 is grounded, the base of the second transistor TR2 is connected to the output end of the voltage stabilizing circuit 12 through the third resistor R3, the collector of the second transistor TR2 is connected to the base of the third transistor TR3, the emitter of the third transistor TR3 is grounded, and the collector of the third transistor TR3 is connected to the output end of the voltage stabilizing circuit 12 through the fourth resistor R4 and the voltage-dividing resistor R0.

[0038] When LED1 works normally, the first transistor TR1 is turned on, the second transistor TR2 is turned on, the base of the third transistor TR3 is pulled to the ground, the third transistor TR3 is turned off, the fourth resistor R4 is not pulled to the ground, and the subsequent LED2, LED3... to be tested are not short-circuited or open-circuited, that is, all subsequent fourth resistors R4 and eighth resistors R8 are not pulled to the ground, and the voltage detected by the AD Detect port is the output voltage of the voltage stabilizing circuit 12, that is, 5V; when LED1 is short-circuited, there is no voltage at the base of the first transistor TR1, the first transistor TR1 is turned off, the second transistor TR2 is turned off, the third transistor TR3 is turned on, the fourth resistor R4 is pulled to the ground, and the voltage detected by the ADDetect port is the voltage-dividing value of the voltage-dividing resistor R0 and the fourth resistor R4.

[0039] In the above embodiment, the open circuit diagnosis circuit 3 includes: a fourth transistor TR4, a fifth transistor TR5, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8; the filtering anti-reverse circuit 11 is connected to the base of the fourth transistor TR4 through the forward-conducting LED to be tested and the fifth resistor R5, the base of the fourth transistor TR4 is grounded through the sixth resistor R6, the collector of the fourth transistor TR4 is connected to the output end of the voltage stabilizing circuit 12 through the seventh resistor R7, the collector of the fourth transistor TR4 is connected to the fifth transistor TR5, the emitter of the fifth transistor TR5 is grounded, and the collector of the fifth transistor TR5 is connected to the collector of the third transistor TR3 through the eighth resistor R8.

[0040] Exemplarily, if the short-circuit diagnostic circuit 3 and the open-circuit diagnostic short circuit 4 are connected to an LED 1 to be tested, when LED 1 works normally, there is no voltage at the base of the fourth transistor TR4, the fourth transistor TR4 is cut off, the fifth transistor TR5 is turned on, and the eighth resistor R8 is not pulled to the ground. When the subsequent LEDs 2, LED 3, etc. to be tested are not short-circuited or open-circuited, the eighth resistor R8 and the fourth resistor R4 are not pulled to the ground. The voltage detected by the AD Detect port is the voltage at the output end of the voltage stabilizing circuit 12, that is, 5V; when LED 1 is open-circuited, there is no voltage at the base of the fourth transistor TR4, the fourth transistor TR4 is cut off, the fifth transistor TR5 is turned on, and the eighth resistor R8 is pulled to the ground. At this time, the voltage detected by the AD Detect port is the voltage divided by the voltage divider resistor R0 and the eighth resistor R8.

[0041] In the above embodiment, the first transistor TR1 is a PNP transistor, and the second transistor TR2, the third transistor TR3, the fourth transistor TR4 and the fifth transistor TR5 are all NPN transistors.

[0042] In order to detect the power supply circuit 1, the present embodiment also includes a power open circuit diagnostic circuit 5 connected between the voltage divider resistor R0 and the short circuit diagnostic circuit 3. The MCU control circuit 2 is also connected to the power open circuit diagnostic circuit 5 to obtain a third diagnostic voltage of the power open circuit diagnostic circuit 5 and determine whether the power supply circuit 1 is open based on the diagnostic voltage.

[0043] Specifically, the power supply open circuit diagnosis circuit 5 includes: a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a sixth transistor TR6 and a seventh transistor TR7; the output end of the filter anti-reverse circuit 11 is grounded through the ninth resistor R9 and the tenth resistor R10, the base of the sixth transistor TR6 is grounded through the tenth resistor R10, the emitter of the sixth transistor TR6 is grounded, the collector of the sixth transistor TR6 is connected to the output end of the voltage stabilization circuit 12 through the eleventh resistor R11, the base of the seventh transistor TR7 is connected to the collector of the sixth transistor TR6, the emitter of the seventh transistor TR7 is grounded, and the collector of the seventh transistor TR7 is connected to the output end of the voltage stabilization circuit 12 through the twelfth resistor R12 and the voltage divider resistor R0. When the power supply circuit 1 works normally, AD The voltage detected by the Detect port is the voltage at the output end of the voltage stabilizing circuit 12. When the power supply circuit 1 is open, the voltage detected by the ADDetect port is the voltage divided by the voltage divider resistor R0 and the twelfth resistor R12. The principle of the power open circuit diagnostic circuit 5 is consistent with the principle of the open circuit diagnostic circuit 4, and will not be repeated again.

[0044] After adding the open-circuit power supply diagnostic circuit 5, when the LED 1 to be tested is open-circuited, the voltage detected by AD Detect is the divided voltage value of the voltage-dividing resistor R0 and the fourth resistor R4 and the eighth resistor R8; when the LED 1 to be tested is short-circuited, the voltage detected by AD Detect is the divided voltage value of the voltage-dividing resistor R0 and the twelfth resistor R12 and the fourth resistor R4.

[0045] In the above embodiment, it also includes: a power device 6, a filtering anti-reverse circuit 11, and a grounding through the forward-conducting LED1, LED2...LEDn to be tested and the power device 6. The LED to be tested in this embodiment can be multiple LEDs connected in series, and finally grounded through the power device 6. In addition, the LED to be tested can be connected in series, in parallel, or in a mixed manner.

[0046] When there are multiple LEDs to be tested connected in series, when the power circuit 1 works normally, the voltage detected by the AD Detect port is the output power of the voltage stabilizing circuit, that is, 5V. When the power supply is open, the voltage value detected by the AD Detect port is the divided voltage value of the resistor divider R0 and the twelfth resistor R12. When LED1 is open, the voltage value detected by the AD Detect port is the divided voltage value of the resistor divider R0, the twelfth resistor R12 and the eighth resistor R8. When LED1 is short-circuited, the voltage value detected by the AD Detect port is the divided voltage value of the resistor divider R0, the twelfth resistor R12, the fourth resistor R4 and the eighth resistor R8. When LED2 is open, the voltage value detected by the AD Detect port is the divided voltage value of the resistor divider R0, the twelfth resistor R12, the fourth resistor R4, the eighth resistor R8 and the fourth resistor R4. When LED2 is short-circuited, the voltage value detected by the AD Detect port is the divided voltage value of the resistor divider R0, the twelfth resistor R12, the fourth resistor R4, the eighth resistor R8, the fourth resistor R4 and the eighth resistor R8. By analogy, when the nth LED is open, AD The voltage value detected by the Detect port is the voltage divided value of the resistor divider R0 and the twelfth resistor R12, the fourth resistor R4, the eighth resistor R8, the fourth resistor R4, the eighth resistor R8... the fourth resistor R4 (wherein, each fourth resistor R4 belongs to a different short-circuit diagnostic circuit 3, each eighth resistor R8 belongs to a different open-circuit diagnostic circuit 4, and there are n corresponding fourth resistors R4 and eighth resistors R8 for n LEDs to be tested). When LED n is short-circuited, the voltage value detected by the AD Detect port is the voltage divided value of the resistor divider R0 and the twelfth resistor R12, the fourth resistor R4, the eighth resistor R8, the fourth resistor R4, the eighth resistor R8... the eighth resistor R8 (wherein, each fourth resistor R4 belongs to a different short-circuit diagnostic circuit 3, and each eighth resistor R8 belongs to a different open-circuit diagnostic circuit 4). Since the voltage divided values ​​are different under different fault conditions, the MCU chip U2 can determine what kind of fault has occurred in which specific LED position based on this.

[0047] Preferably, the filtering and anti-reverse circuit 11 includes: a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a thirteenth resistor R13, a bidirectional voltage regulator TVS1 and an anti-reverse diode D1. The positive electrode of the power supply is grounded through the fifth capacitor C5 and the sixth capacitor C6, the positive electrode of the power supply is grounded through the seventh capacitor R7 and the eighth capacitor R8, the positive electrode of the power supply is grounded through the thirteenth resistor R13, the positive electrode of the power supply is grounded through the bidirectional voltage regulator TVS1, and the positive electrode of the power supply is used as the output of the anti-reverse filtering circuit 11 through the forward-conducting diode D1, wherein the fifth capacitor C5 and the sixth capacitor C6 are composed of capacitors with small capacitance, the seventh capacitor C7 and the eighth capacitor C8 are composed of capacitors with large capacitance, and the thirteenth resistor R13 is a leakage resistor. Through the filtering and anti-reverse circuit 11, a stable power input can be provided for subsequent circuits.

[0048] In summary, this embodiment only requires one MCU A / D detection port, which can not only detect the open circuit and short circuit status of all LEDs, but also accurately locate the position of the faulty LED and feed back the information to the MCU. By reading the fault feedback information of the MCU, it is greatly convenient for us to analyze the failure problems of LED products, and according to the fault information, the MCU can also optimize and safely process the entire circuit according to the different working conditions of the LED.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An LED detection device, It is characterized in that include: Power supply circuit, MCU control circuit, several short circuit diagnosis circuits and several open circuit diagnosis circuits; The power supply circuit is connected to the short-circuit diagnosis circuit, the open-circuit diagnosis circuit and the MCU control circuit, and is used to provide power to the short-circuit diagnosis circuit, the open-circuit diagnosis circuit and the MCU control circuit; Each LED to be tested is connected to the short-circuit diagnostic circuit and the open-circuit diagnostic circuit; The MCU control circuit is connected in series with a plurality of the short-circuit diagnostic circuits and a plurality of the open-circuit diagnostic circuits, and is used to obtain a diagnostic voltage after the short-circuit diagnostic circuit and the open-circuit diagnostic circuit are connected in series, and the MCU control circuit determines whether the LED to be tested is short-circuited or open-circuited according to the diagnostic voltage; The power supply circuit comprises: a filtering and anti-reverse circuit and a voltage stabilizing circuit; The input end of the filter anti-reverse circuit is connected to a DC power supply, the output end of the filter anti-reverse circuit is connected to the input end of the voltage stabilizing circuit and the LED to be tested, and the output end of the voltage stabilizing circuit is connected to the open circuit diagnosis circuit, the short circuit diagnosis circuit and the MCU control circuit; It also includes a voltage-dividing resistor, and the output end of the voltage-stabilizing circuit is connected to the short-circuit diagnosis circuit, the open-circuit diagnosis circuit and the MCU control circuit through the voltage-dividing resistor; The short circuit diagnosis circuit comprises: a first triode, a second triode, a third triode, a first resistor, a second resistor, a third resistor and a fourth resistor; The filtering and anti-reverse circuit is connected to the base of the first transistor through the forward-conducting LED to be tested, the filtering and anti-reverse circuit is connected to the emitter of the first transistor through the first resistor, the collector of the first transistor is grounded through the second resistor, the collector of the first transistor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the base of the second transistor is connected to the output end of the voltage stabilizing circuit through the third resistor, the collector of the second transistor is connected to the base of the third transistor, the emitter of the third transistor is grounded, and the collector of the third transistor is connected to the output end of the voltage stabilizing circuit through the fourth resistor and the voltage dividing resistor.

2. The LED detection device according to claim 1, It is characterized in that The voltage stabilizing circuit includes: a voltage stabilizing chip, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor. The first end of the voltage stabilizing chip is the input end of the voltage stabilizing circuit, the first end of the voltage stabilizing chip is connected to the output end of the filtering and anti-reverse circuit, the first end of the voltage stabilizing chip is grounded through the first capacitor, the first end of the voltage stabilizing chip is grounded through the second capacitor, the second end, the third end and the fourth end of the voltage stabilizing chip are grounded, the fifth end of the voltage stabilizing chip is grounded through the third capacitor, the fifth end of the voltage stabilizing chip is grounded through the fourth capacitor, and the fifth end of the voltage stabilizing chip is the output end of the voltage stabilizing circuit.

3. The LED detection device according to claim 1, It is characterized in that The open circuit diagnosis circuit comprises: a fourth transistor, a fifth transistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The filtering and anti-reverse circuit is connected to the base of the fourth transistor through the forward-conducting LED to be tested and the fifth resistor, the base of the fourth transistor is grounded through the sixth resistor, the collector of the fourth transistor is connected to the output end of the voltage stabilizing circuit through the seventh resistor, the collector of the fourth transistor is connected to the fifth transistor, the emitter of the fifth transistor is grounded, and the collector of the fifth transistor is connected to the collector of the third transistor through the eighth resistor.

4. The LED detection device according to claim 3, It is characterized in that The first transistor is a PNP transistor, and the second transistor, the third transistor, the fourth transistor and the fifth transistor are all NPN transistors.

5. The LED detection device according to claim 1, It is characterized in that It also includes a power open circuit diagnostic circuit connected between the voltage divider resistor and the short circuit diagnostic circuit. The MCU control circuit is also connected to the power open circuit diagnostic circuit to obtain a third diagnostic voltage of the power open circuit diagnostic circuit and determine whether the power circuit is open based on the diagnostic voltage.

6. The LED detection device according to claim 5, It is characterized in that The power open circuit diagnosis circuit comprises: a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a sixth transistor and a seventh transistor; The output end of the filtering and anti-reverse circuit is grounded through the ninth resistor and the tenth resistor, the base of the sixth transistor is grounded through the tenth resistor, the emitter of the sixth transistor is grounded, the collector of the sixth transistor is connected to the output end of the voltage stabilizing circuit through the eleventh resistor, the base of the seventh transistor is connected to the collector of the sixth transistor, the emitter of the seventh transistor is grounded, and the collector of the seventh transistor is connected to the output end of the voltage stabilizing circuit through the twelfth resistor and the voltage dividing resistor.

7. The LED detection device according to claim 1, It is characterized in that Also includes: The power device, the filtering and anti-reverse circuit is connected to the ground through the forward-conducting LED to be tested and the power device.

Images