Power-off holding circuit and LED lighting lamp

Abstract

The disclosure provides a power-off holding circuit and an LED lighting lamp; the power-off holding circuit comprises a first capacitor and a master control circuit; the first capacitor is electrically connected with an output end of a rectifier circuit and an LED load respectively, and a second end of the first capacitor is connected with a signal ground; the master control circuit comprises a voltage stabilizing circuit, a control circuit and a dimming circuit; the voltage stabilizing circuit comprises a voltage stabilizing tube, a first voltage dividing module and a first filter module; a cathode of the voltage stabilizing tube is electrically connected with a first end of the first capacitor, and the cathode of the voltage stabilizing tube is also electrically connected with an input end of the control circuit; an anode of the voltage stabilizing tube is electrically connected with a first end of the first voltage dividing module; a voltage dividing node end of the first voltage dividing module is also electrically connected with a first end of the first filter module and an enable end of the control circuit respectively, and a second end of the first voltage dividing module and a second end of the first filter module are connected with the signal ground; an output end of the control circuit is electrically connected with a power supply end of the dimming circuit; a first dimming end of the dimming circuit is electrically connected with the second end of the first capacitor, and a second dimming end of the dimming circuit is electrically connected with a negative end of the LED load.

Description

Technical Field

[0001] This disclosure relates to the field of lighting technology, and in particular to a power-off retention circuit and an LED lighting fixture. Background Technology

[0002] Dimmable lighting products are widely used in hotels, homes, and shopping malls due to their ability to change color and brightness. These effects rely on dimming modules. These modules typically use DALI (Digital Addressable Lighting Interface) or Bluetooth dimming modules and must be able to maintain operation for a certain period after AC power is disconnected. This allows the module sufficient time to store data after power loss. However, to ensure the stability of the dimming lighting product, this maintenance time must be neither too short nor too long.

[0003] Existing power-off retention circuits use a linear regulator or switching power supply matched with a capacitor. The capacitor stores energy when AC power is applied and discharges to power the dimming module when AC power is disconnected. The discharge time of the capacitor is limited by the linear regulator or switching power supply circuit. However, the linear regulator tends to overheat after prolonged operation, affecting its lifespan. Additionally, the switching power supply circuit has more components, resulting in a more complex circuit structure. Utility Model Content

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a power-off retention circuit and LED lighting fixture with a simple structure and extended lifespan.

[0005] The purpose of this disclosure is achieved through the following technical solution: A power-off retention circuit, comprising: The first capacitor is used to be electrically connected to the output terminal of the rectifier circuit and the LED load respectively, and the second terminal of the first capacitor is connected to the signal ground. The main control circuit includes a voltage regulator circuit, a control circuit, and a dimming circuit. The voltage regulator circuit includes a Zener diode, a first voltage divider module, and a first filter module. The cathode of the Zener diode is electrically connected to the first terminal of a first capacitor, and the cathode of the Zener diode is also electrically connected to the input terminal of the control circuit. The anode of the Zener diode is electrically connected to the first terminal of the first voltage divider module. The voltage divider node of the first voltage divider module is also electrically connected to the first terminal of the first filter module and the enable terminal of the control circuit, respectively. The second terminals of the first voltage divider module and the second terminals of the first filter module are connected to signal ground. The output terminal of the control circuit is electrically connected to the power supply terminal of the dimming circuit. The first dimming terminal of the dimming circuit is electrically connected to the second terminal of the first capacitor, and the second dimming terminal of the dimming circuit is electrically connected to the negative terminal of the LED load.

[0006] In one embodiment, the first voltage divider module includes a first resistor and a second resistor. The first end of the first resistor is electrically connected to the anode of the Zener diode, and the second end of the first resistor is electrically connected to the first end of the second resistor and the first end of the first filter module, respectively. The second end of the second resistor is connected to signal ground.

[0007] In one embodiment, the first filtering module includes a second capacitor, a first terminal of the second capacitor is electrically connected to a first terminal of the second resistor, the first terminal of the second capacitor is also electrically connected to the enable terminal of the control circuit, and the second terminal of the second capacitor is connected to signal ground.

[0008] In one embodiment, the control circuit includes a control module, a step-down module, a second voltage divider module, and a second filter module. The input terminal of the control module is electrically connected to the cathode of the Zener diode. The output terminal of the control module is electrically connected to the power supply terminal of the dimming circuit in sequence through the step-down module, the second voltage divider module, and the second filter module.

[0009] In one embodiment, the dimming circuit includes a dimming module and a switching module. The power supply terminal of the dimming module is electrically connected to the output terminal of the control circuit. The modulation terminal of the dimming module is electrically connected to the control terminal of the switching module. The first terminal of the switching module is electrically connected to the second terminal of the first capacitor. The second terminal of the switching module is used to be electrically connected to the negative terminal of the LED load.

[0010] In one embodiment, the capacitance of the first capacitor is 470μF~1000μF.

[0011] In one embodiment, the reverse breakdown voltage of the Zener diode is 12V~15V.

[0012] An LED lighting fixture includes a rectifier circuit, an LED load, and a power-off retention circuit according to any of the above embodiments. The input terminal of the rectifier circuit is connected to AC power, and the output terminal of the rectifier circuit is connected in parallel with a first capacitor. The positive terminal of the LED load is electrically connected to the first terminal of the first capacitor.

[0013] In one embodiment, the rectifier circuit includes a rectifier module, an APFC module, a third capacitor, an isolation module, and a first diode. The input terminal of the rectifier module is used to connect to AC power, and the output terminal of the rectifier module is electrically connected to the input terminal of the APFC module. The output terminal of the APFC module is connected in parallel with the third capacitor, and the output terminal of the APFC module is also electrically connected to the input terminal of the isolation module. The third capacitor is electrically connected to the input terminal of the isolation module. The output terminal of the isolation module is electrically connected to the anode of the first diode. The cathode of the first diode is electrically connected to the first terminal of the first capacitor.

[0014] In one embodiment, the rectifier circuit rectifies the output voltage to 24V.

[0015] Compared with the prior art, this disclosure has at least the following advantages: After the AC power is disconnected, the dimming circuit is powered through the first capacitor, enabling the dimming circuit to operate for a certain period of time. At the same time, the voltage release time of the first capacitor can be adjusted by the reverse breakdown voltage value of the selected Zener diode. By using the reverse breakdown voltage characteristic of the Zener diode to replace the linear regulator or switching power supply circuit, the service life of the power-off retention circuit is extended and the structure of the power-off retention circuit is simplified. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a power-off retention circuit according to an embodiment of the present invention; Figure 2 This is a circuit diagram of a power-off retention circuit according to an embodiment of the present invention; Figure label: Power-off retention circuit 10; First capacitor EC2; Main control circuit 100; Zener circuit 1001; Zener diode ZD1; First voltage divider module 1001A; First resistor R3; Second resistor R4; First filter module 1001B; Second capacitor C2; Control circuit 1002; Control module 1002A; Resistor R5; Capacitor C3 1002B step-down module; diode D1; inductor L1 Second voltage divider module 1002C; Resistor R1; Resistor R2; Second filter module 1002D; capacitor EC3; capacitor C1 Dimming circuit 1003; Dimming module 1003A; Switching module 1003B 20 LED lighting fixtures; 200 rectifier circuits; 300 LED loads; Rectifier circuit 200; rectifier module 2001, APFC module 2002, third capacitor EC1, isolation module 2003; first diode D2. Detailed Implementation

[0018] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments: Please see Figure 1 This utility model provides a circuit diagram of a power-off retention circuit 10.

[0022] Please see Figure 2The power-off holding circuit 10 includes a first capacitor EC2 and a main control circuit 100.

[0023] The first capacitor EC2 is electrically connected to both the output terminal of the rectifier circuit and the LED load, and the second terminal of the first capacitor EC2 is connected to signal ground. The main control circuit 100 includes a voltage regulator circuit 1001, a control circuit 1002, and a dimming circuit 1003. The voltage regulator circuit 1001 includes a Zener diode ZD1, a first voltage divider module 1001A, and a first filter module 1001B. The cathode of the Zener diode ZD1 is electrically connected to the first terminal of the first capacitor EC2, and the cathode of the Zener diode ZD1 is also electrically connected to the input terminal of the control circuit 1002. The anode is electrically connected to the first terminal of the first voltage divider module 1001A; the voltage divider node of the first voltage divider module 1001A is also electrically connected to the first terminal of the first filter module 1001B and the enable terminal of the control circuit 1002, respectively, and the second terminal of the first voltage divider module 1001A and the second terminal of the first filter module are connected to signal ground; the output terminal of the control circuit 1002 is electrically connected to the power supply terminal of the dimming circuit 1003; the first dimming terminal of the dimming circuit is electrically connected to the second terminal of the first capacitor, and the second dimming terminal of the dimming circuit 1003 is electrically connected to the negative terminal of the LED load.

[0024] In this embodiment, when AC power is input, the AC power is rectified by the rectifier circuit 200 to output DC power with voltage V0. The noise of V0 is filtered out by the first capacitor EC2 to improve the stability and reliability of the LED load 300. At the same time, the first capacitor EC2 stores energy in the voltage V0. When V0 is greater than the reverse breakdown voltage V1 of the Zener diode ZD1, the Zener diode ZD1 is turned on. V0 is divided by the voltage divider node of the first voltage divider module 1001A and filtered by the first filter module 1001B to generate an enable voltage EN. The enable terminal of the control circuit 1002 receives the enable voltage EN and starts to control the dimming circuit 1003 to work.

[0025] When the AC input is turned off, voltage V0 is released across the first capacitor EC2, causing V0 to drop. When the voltage V0 released by the first capacitor EC2 drops to the same level as the conduction threshold voltage of the LED load 300, the LED load 300 will stop working, and at this time, the LED load 300 is in an open circuit state. Voltage V0 is slowly discharged through the Zener diode ZD1, the first voltage divider module 1001A, and the first filter module 1001B. When voltage V0 is less than the reverse breakdown voltage of the Zener diode ZD1, the Zener diode ZD1 is cut off, causing the control circuit 1002 to be de-energized and stop working. The control circuit 1002 cannot control the dimming circuit, causing the dimming circuit 1003 to turn off.

[0026] Thus, after the AC power is disconnected, the dimming circuit 1003 is powered through the first capacitor EC2, giving the dimming circuit 1003 a certain working time. At the same time, the voltage release time of the first capacitor EC2 can be adjusted by the reverse breakdown voltage value of the selected Zener diode ZD1. By using the reverse breakdown voltage characteristic of Zener diode ZD1 to replace the linear regulator or switching power supply circuit, the service life of the power-off retention circuit is extended and the structure of the power-off retention circuit is simplified.

[0027] In one embodiment, the first voltage divider module 1001A includes a first resistor R3 and a second resistor R4. The first end of the first resistor R3 is electrically connected to the anode of the Zener diode ZD1. The second end of the first resistor R3 is electrically connected to the first end of the second resistor R4 and the first end of the first filter module 1001B, respectively. Specifically, the second end of the first resistor R3 or the first end of the second resistor R4 is the voltage divider node of the first voltage divider module; the second end of the second resistor R4 is connected to signal ground. Thus, V0 is divided by the first resistor R3 and the second resistor R4 to generate an enable voltage EN, preventing excessively high enable voltage EN from being input to the control circuit 1002 and causing damage. The enable terminal of the control circuit is active high.

[0028] In one embodiment, the first filter module 1001B includes a second capacitor C2. The first terminal of the second capacitor C2 is connected to the first terminal of the second resistor R3. The first terminal of the second capacitor C2 is also electrically connected to the enable terminal of the control circuit 1002. The second terminal of the second capacitor C2 is connected to signal ground. Thus, capacitor C2 smooths the ripple on the enable voltage EN, preventing the ripple of the enable voltage EN from causing instability in the operation of the control circuit 1002.

[0029] In one embodiment, the control circuit 1002 includes a control module 1002A, a step-down module 1002B, a second voltage divider module 1002C, and a second filter module 1002D. The input terminal of the control module 1002A is electrically connected to the cathode of the Zener diode ZD1. The output terminal of the control module 1002A is electrically connected to the power supply terminal of the dimming circuit 1003 in sequence through the step-down module 1002B, the second voltage divider module 1002C, and the second filter module 1002D.

[0030] In this embodiment, the control module 1002A uses the SY8511ADC chip, the step-down module 1002B uses the diode D1 and the inductor L1, the second voltage divider module 1002C uses the resistor R1 and the resistor R2, and the second filter module 1002D uses the capacitor EC3 and the capacitor C1. It should be noted that the enable voltage EN is input to the VIN terminal of the control module 1002A for power supply. The LX terminal of the control module 1002A is used to output and control the switching voltage VCC. When the switching voltage VCC passes through the step-down topology formed by diode D1 and inductor L1, the voltage value of the switching voltage VCC is reduced to avoid damage to the dimming circuit 1003 due to excessive voltage value of the switching voltage VCC. A resistor R5 and a capacitor C3 are connected in series between the BS terminal and the LX terminal of the control module 1002A to filter and limit the current of the switching voltage VCC of the control module 1002A. The FB terminal of the control module 1002A can detect the voltage between R1 and R2, thereby adjusting the value of the output voltage VCC. The capacitors EC3 and C1 filter the switching voltage VCC input to the dimming circuit 1003 to reduce the noise of the switching voltage VCC input to the dimming circuit 1003, so that the dimming circuit 1003 can work stably.

[0031] In one embodiment, the dimming circuit 1003 includes a dimming module 1003A and a switching module 1003B. The power supply terminal of the dimming module 1003A is electrically connected to the output terminal of the control circuit 1002. The modulation terminal of the switching module is connected to the control terminal of the switching module 1003B. The first terminal of the switching module 1003B is electrically connected to the second terminal of the first capacitor EC2. The second terminal of the switching module 1003B is used to electrically connect to the negative terminal of the LED load.

[0032] In this embodiment, the dimming module 1003A is a DALI dimming module, and the switching module 1003B is an NMOS transistor. When the control module 3201 outputs a switching voltage VCC to the VCC terminal of the dimming module 3301, the dimming module 1002A is powered on and operates. It outputs a PWM signal from the PWM-OUT terminal to control the NMOS transistor to conduct in order to dim the LED load 300. When AC power is input, the dimming module 1003A operates normally and outputs a high-level PWM signal from the PWM-OUT terminal. The PWM signal is input to the gate of the NMOS transistor, causing the NMOS transistor to conduct, thereby enabling the dimming module 1003A to dim the LED load.

[0033] In this embodiment, the capacitance of the first capacitor EC2 is 470μF~1000μF, and in this embodiment, the capacitance of the first capacitor EC2 is 800μF.

[0034] In this embodiment, the reverse breakdown voltage of the Zener diode ZD1 is 12~15V. In this embodiment, the reverse breakdown voltage of the Zener diode ZD1 is 14V.

[0035] Please see Figure 2 This application also provides an LED lighting fixture 20, including a rectifier circuit 200, an LED load 300, and a power-off retention circuit 10 of any of the above embodiments. The input terminal of the rectifier circuit 200 is used to connect to AC power, the output terminal of the rectifier circuit 200 is connected in parallel with a first capacitor EC2, and the positive terminal of the LED load 300 is electrically connected to the first terminal of the first capacitor EC2.

[0036] In this embodiment, after the AC input rectifier circuit 200 rectifies the AC power, the output terminal of the rectifier circuit 200 outputs a DC voltage V0. The voltage V0 supplies power to the LED load 300 and, after passing through the Zener diode ZD1, supplies power to the control circuit 1002, enabling the control circuit 1002 to control the dimming circuit 1003. The voltage V0, after being output by the rectifier circuit 200, is simultaneously stored in the first capacitor EC2.

[0037] In one embodiment, the rectifier circuit 200 includes a rectifier module 2001, an APFC module 2002, a third capacitor EC1, an isolation module 2003, and a first diode D2. The input terminal of the rectifier module 2001 is used to connect to AC power, and the output terminal of the rectifier module 2001 is electrically connected to the input terminal of the APFC module 2002. The output terminal of the APFC module 2002 is connected in parallel with the third capacitor EC1, and the output terminal of the APFC module 2002 is also electrically connected to the input terminal of the isolation module 2003. The third capacitor EC1 is electrically connected to the input terminal of the isolation module 2003. The output terminal of the isolation module 2003 is electrically connected to the anode of the first diode D2. The cathode of the first diode D1 is electrically connected to the first terminal of the first capacitor EC1.

[0038] In this embodiment, the rectifier module 2001 uses a GBU1508 bridge rectifier module to rectify the AC power into a unidirectional pulsating voltage; the APFC module 2002 is an active power factor correction module to reduce voltage fluctuations in the input AC power and improve the stability of the rectifier circuit 100; the third capacitor EC1 converts the unidirectional pulsating voltage into high-voltage DC power; the isolation module 2003 uses a flyback converter to invert and step down the high-voltage DC power; the first diode D2 blocks the reverse current from capacitor C2 from flowing back through the isolation module 140, thus preventing a decrease in the efficiency of the rectifier circuit 100. In this embodiment, the AC power is rectified into a unidirectional pulsating voltage by the rectifier module 2001. After the unidirectional pulsating voltage passes through the APFC module 2002, the fluctuations of the unidirectional pulsating voltage are smoothed. Then, the third capacitor EC1 filters the unidirectional pulsating voltage into high-voltage DC power. After that, the isolation module 2003 inverts and steps down the high-voltage DC power, and finally, the first diode D2 outputs V0 from the first capacitor EC2.

[0039] In this embodiment, the rectifier circuit 200 rectifies and outputs a voltage of 24V.

[0040] When AC power is input, the power-off retention circuit 10 of this application: rectifier module 2001 rectifies the voltage into a unidirectional pulsating voltage. After passing through APFC module 2002, the fluctuation of the unidirectional pulsating voltage is smoothed. Then, capacitor EC1 of second filter module 130 filters the unidirectional pulsating voltage into high-voltage DC power. After that, isolation module 2003 inverts and steps down the high-voltage DC power. Finally, the voltage V0 is output through first diode D2 to the first capacitor EC2 for storage. Voltage V0 is also input to control module 1002A for power supply. Voltage V0 is greater than the reverse breakdown voltage of Zener diode ZD1. After being divided by first resistor R3 and second resistor R4 and filtered by capacitor C2, V0 generates an enable voltage EN, which is sent to the enable terminal EN of control module 1002A, so that control module 1002A controls dimming module 1003A to dim the LED load. When the AC input is disconnected: voltage V0 is released by the first capacitor EC2. Voltage V0 gradually decreases over time. When the voltage U1 released by the first capacitor EC2 drops to the same as the conduction threshold voltage of the LED load 300, the LED load 300 will stop working, and at this time the LED load 300 is in an open circuit state. The voltage V1 released by the first capacitor EC2 will be slowly discharged through the Zener diode ZD1, the first resistor R3, the second resistor R4 and the second capacitor C2. When voltage V1 is less than the reverse breakdown voltage of the Zener diode ZD1, the Zener diode ZD1 will not conduct, causing the control module 1002A to be powered off and stop controlling the dimming module 1003A, thus turning off the dimming circuit 1003.

[0041] Compared with the prior art, this disclosure has at least the following advantages: Thus, after the AC power is disconnected, the dimming circuit 1003 is powered through the first capacitor EC2, giving the dimming circuit 1003 a certain working time. At the same time, the voltage release time of the first capacitor EC2 can be adjusted by the reverse breakdown voltage value of the selected Zener diode ZD1. By using the reverse breakdown voltage characteristic of Zener diode ZD1 to replace the linear regulator or switching power supply circuit, the service life of the power-off retention circuit is extended and the structure of the power-off retention circuit is simplified.

[0042] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A power-off retention circuit, characterized in that, include: The first capacitor is used to be electrically connected to the output terminal of the rectifier circuit and the LED load respectively, and the second terminal of the first capacitor is connected to the signal ground. The main control circuit includes a voltage regulator circuit, a control circuit, and a dimming circuit. The voltage regulator circuit includes a Zener diode, a first voltage divider module, and a first filter module. The cathode of the Zener diode is electrically connected to the first terminal of a first capacitor, and the cathode of the Zener diode is also electrically connected to the input terminal of the control circuit. The anode of the Zener diode is electrically connected to the first terminal of the first voltage divider module. The voltage divider node of the first voltage divider module is also electrically connected to the first terminal of the first filter module and the enable terminal of the control circuit, respectively. The second terminals of the first voltage divider module and the second terminals of the first filter module are connected to signal ground. The output terminal of the control circuit is electrically connected to the power supply terminal of the dimming circuit. The first dimming terminal of the dimming circuit is electrically connected to the second terminal of the first capacitor, and the second dimming terminal of the dimming circuit is electrically connected to the negative terminal of the LED load.

2. The power-off retention circuit according to claim 1, characterized in that, The first voltage divider module includes a first resistor and a second resistor. The first end of the first resistor is electrically connected to the anode of the Zener diode. The second end of the first resistor is electrically connected to the first end of the second resistor and the first end of the first filter module, respectively. The second end of the second resistor is connected to signal ground.

3. The power-off retention circuit according to claim 2, characterized in that, The first filtering module includes a second capacitor. The first end of the second capacitor is electrically connected to the first end of the second resistor. The first end of the second capacitor is also electrically connected to the enable terminal of the control circuit. The second end of the second capacitor is connected to signal ground.

4. The power-off retention circuit according to claim 1, characterized in that, The control circuit includes a control module, a step-down module, a second voltage divider module, and a second filter module. The input terminal of the control module is electrically connected to the cathode of the Zener diode. The output terminal of the control module is electrically connected to the power supply terminal of the dimming circuit in sequence through the step-down module, the second voltage divider module, and the second filter module.

5. The power-off retention circuit according to claim 1, characterized in that, The dimming circuit includes a dimming module and a switching module. The power supply terminal of the dimming module is electrically connected to the output terminal of the control circuit. The modulation terminal of the dimming module is electrically connected to the control terminal of the switching module. The first terminal of the switching module is electrically connected to the second terminal of the first capacitor. The second terminal of the switching module is used to electrically connect to the negative terminal of the LED load.

6. The power-off retention circuit according to claim 1, characterized in that, The capacitance of the first capacitor is 470μF~1000μF.

7. The power-off retention circuit according to claim 1, characterized in that, The reverse breakdown voltage of the Zener diode is 12V~15V.

8. An LED lighting fixture, characterized in that, The device includes a rectifier circuit, an LED load, and a power-off retention circuit as described in any one of claims 1-7. The input terminal of the rectifier circuit is connected to AC power, and the output terminal of the rectifier circuit is connected in parallel with a first capacitor. The positive terminal of the LED load is electrically connected to the first terminal of the first capacitor.

9. The LED lighting fixture according to claim 8, characterized in that, The rectifier circuit includes a rectifier module, an APFC module, a third capacitor, an isolation module, and a first diode. The input terminal of the rectifier module is used to connect to AC power, and the output terminal of the rectifier module is electrically connected to the input terminal of the APFC module. The output terminal of the APFC module is connected in parallel with the third capacitor, and the output terminal of the APFC module is also electrically connected to the input terminal of the isolation module. The third capacitor is electrically connected to the input terminal of the isolation module. The output terminal of the isolation module is electrically connected to the anode of the first diode. The cathode of the first diode is electrically connected to the first terminal of the first capacitor.

10. The LED lighting fixture according to claim 8, characterized in that, The rectifier circuit outputs a voltage of 24V.

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