LED short-circuit protection circuit

Abstract

The utility model belongs to the technical field of electronic circuits, and provides an LED short-circuit protection circuit, which comprises a step-down constant-current circuit, a color temperature adjusting circuit and a short-circuit protection circuit, the short-circuit protection circuit is connected with the step-down constant-current circuit and the color temperature adjusting circuit. And the short-circuit protection circuit is used for transmitting a short-circuit signal in the color temperature adjusting circuit to the step-down constant-current circuit when a component in the color temperature adjusting circuit is short-circuited, so that the step-down constant-current circuit executes a protection mechanism. According to the LED short-circuit protection circuit provided by the utility model, the circuit can be cut off in an extremely short time, and devices are effectively prevented from being damaged; and an anti-error protection effect can be achieved by adjusting device parameters in the circuit.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to an LED short-circuit protection circuit. Background Technology

[0002] Currently, there are various LED short-circuit protection technologies on the market, but they generally adopt the method of chip sampling voltage and output control. Although this method has the advantages of high efficiency and flexible application, it also has the problem that when an LED experiences a momentary false short circuit, the existing short-circuit protection circuit may not be able to accurately identify it, thus causing the short-circuit protection to malfunction.

[0003] When an accidental short circuit occurs between LED output lines, a surge voltage can be generated, causing damage to the device and posing a danger. Therefore, when a short circuit occurs, the short circuit fault must be detected quickly, and the power supply circuit must be cut off in a very short time to prevent damage to the device.

[0004] Traditional circuit protection methods, such as those shown in the appendix Figure 1 As shown, the inductor current differential sampling of the chip is used to control the dimming signal to turn off, generating short-circuit protection; however, this method may fail to detect the short-circuit signal, the dimming signal is not turned off, and the switching device continues to heat up, causing damage.

[0005] Therefore, it is necessary to provide an LED short-circuit protection circuit. Summary of the Invention

[0006] This invention provides an LED short-circuit protection circuit that can cut off the circuit in a very short time, effectively preventing damage to the device; and can achieve the effect of preventing false alarms by adjusting the device parameters in the circuit.

[0007] This utility model provides an LED short-circuit protection circuit, including: a step-down constant current circuit, a color temperature adjustment circuit, and a short-circuit protection circuit; the short-circuit protection circuit is connected to the step-down constant current circuit and the color temperature adjustment circuit respectively; the short-circuit protection circuit is used to transmit the short-circuit signal in the color temperature adjustment circuit to the step-down constant current circuit when a component in the color temperature adjustment circuit is short-circuited, so that the step-down constant current circuit can perform the protection mechanism.

[0008] The short-circuit protection circuit includes Zener diode Z1, Zener diode Z2, resistor R1, resistor R2, diode D1, diode D2, MOSFET Q1, and capacitor C1;

[0009] One end of capacitor C1 is connected to the cathode of Zener diode Z2, the other end of resistor R1, and one end of resistor R2; the other end of capacitor C1 is connected to the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1; the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1 are all grounded.

[0010] The other end of resistor R1 is connected to the gate of MOSFET Q1;

[0011] One end of resistor R1 is connected to the anode of Zener diode Z1; the cathode of Zener diode Z1 is connected to the cathodes of diode D1 and diode D2 respectively.

[0012] The anode of diode D1 is connected to the D1 terminal of transistor Q3, and the D1 terminal of transistor Q3 is connected to the LEDY terminal of the LED lamp; the anode of diode D2 is connected to the D2 terminal of transistor Q3, and the D2 terminal of transistor Q3 is connected to the LEDW terminal of the LED lamp; the drain of MOSFET Q1 is connected to the PWM terminal of the main control chip U1.

[0013] Furthermore, the step-down constant current circuit includes a main control chip U1, resistors R3, R4, R5, R6, R7, R8, R9, R10, capacitors C2, C3, C4, C5, C6, C7, transistor Q2, inductors L1 and L2, and diode D3.

[0014] One end of resistor R3 is connected to one end of capacitor C2; the other end of capacitor C2 is grounded; one end of capacitor C2 is connected to one end of resistor R4, one end of resistor R5 and one end of capacitor C3 respectively; the other ends of resistor R4, resistor R5 and capacitor C3 are all connected to the positive terminal of the LED.

[0015] The other end of resistor R3 is connected to the VCC terminal of the main control chip U1;

[0016] One end of capacitor C3 is connected to the CSP terminal of the main control chip U1;

[0017] The other end of capacitor C3 is connected to the CSN terminal of the main control chip U1;

[0018] One end of resistor R6, one end of resistor R7, and one end of capacitor C4 are all connected to voltage regulator VREF;

[0019] The VREF terminal of the main control chip U1 is connected to the voltage regulator VREF;

[0020] The other end of resistor R7 is connected to one end of resistor R8 and one end of capacitor C5, respectively.

[0021] One end of capacitor C5 is connected to the ADIM terminal of the main control chip U1;

[0022] The other end of resistor R3 is connected to one end of capacitor C6;

[0023] One end of capacitor C7 is connected to the PWM terminal of the main control chip U1;

[0024] One end of resistor R9 is connected to the GATE terminal of the main control chip U1;

[0025] The other end of resistor R9 is connected to one end of resistor R10 and the gate of transistor Q2.

[0026] The drain of transistor Q2 is connected to the anode of diode D3; the cathode of diode D3 is connected to the CSP terminal of the main control chip U1.

[0027] The other ends of resistor R6, resistor R8, capacitor C4, capacitor C5, capacitor C6, capacitor C7, resistor R10, and the source of transistor Q2 are all grounded.

[0028] The anode of diode D3 is connected to one end of inductor L1, and the other end of inductor L1 is connected to one end of inductor L2.

[0029] Furthermore, the color temperature adjustment circuit includes resistors R11, R12, R13, R14, R15, and R16, capacitors C8 and C9, a main control chip U3, and transistor Q3. The G2 terminal of transistor Q3 is connected to one end of resistor R11 and one end of resistor R12. The G1 terminal of transistor Q3 is connected to the other end of resistor R13 and one end of resistor R14. The S1 terminal of transistor Q3 is connected to one end of resistor R13. The other end of resistor R12 is connected to the D1 terminal of the main control chip U3. The other end of resistor R14 is connected to the D2 terminal of the main control chip U3. One end of capacitor C8 is connected to the HV terminal of the main control chip U3. The other end of capacitor C8 is connected to the VS terminal of the main control chip U3. One end of resistor R15 is connected to the HV terminal of the main control chip U3. The other end of resistor R15 is connected to a 48V power supply. The VCC terminal of the main control chip U3 is connected to one end of capacitor C9 and one end of resistor R16. The other end of capacitor C9 is grounded.

[0030] Furthermore, the other end of resistor R16 is connected to the VCC terminal of the main control chip U1; the VS terminal of the main control chip U3 is connected to the other end of inductor L2.

[0031] Furthermore, capacitor C1 is also used to skip the brief overshoot period of about 400ms that exists during normal power-on by charging it, so as to prevent false protection.

[0032] Resistors R1 and R2 are resistors with adjustable sensitivity;

[0033] When the main control chip U1 enters the short-circuit protection state, it can prevent transistor Q3 from overheating and being damaged.

[0034] Compared with the prior art, this utility model has the following advantages and beneficial effects: it can cut off the circuit in a very short time, effectively preventing the device from being damaged; and it can achieve the effect of preventing misoperation by adjusting the device parameters in the circuit.

[0035] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0036] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 This is a schematic diagram of the structure of a traditional short-circuit protection control method;

[0039] Figure 2 This is a schematic diagram of an LED short-circuit protection circuit.

[0040] Figure 3 This is a schematic diagram of the connection structure of a step-down constant current circuit;

[0041] Figure 4 This is a schematic diagram of the color temperature adjustment circuit structure.

[0042] Figure 5 This is a schematic diagram of the short-circuit protection circuit structure. Detailed Implementation

[0043] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0044] This utility model provides an LED short-circuit protection circuit, such as Figure 2 As shown, it includes: a step-down constant current circuit, a color temperature adjustment circuit, and a short-circuit protection circuit; the short-circuit protection circuit is connected to the step-down constant current circuit and the color temperature adjustment circuit respectively; the short-circuit protection circuit is used to transmit the short-circuit signal in the color temperature adjustment circuit to the step-down constant current circuit when a short circuit occurs in a component of the color temperature adjustment circuit, so that the step-down constant current circuit can perform the protection mechanism.

[0045] like Figure 5 As shown, the short-circuit protection circuit includes Zener diode Z1, Zener diode Z2, resistor R1, resistor R2, diode D1, diode D2, MOSFET Q1, and capacitor C1.

[0046] One end of capacitor C1 is connected to the cathode of Zener diode Z2, the other end of resistor R1, and one end of resistor R2; the other end of capacitor C1 is connected to the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1; the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1 are all grounded.

[0047] The other end of resistor R1 is connected to the gate of MOSFET Q1;

[0048] One end of resistor R1 is connected to the anode of Zener diode Z1; the cathode of Zener diode Z1 is connected to the cathodes of diode D1 and diode D2 respectively.

[0049] The anode of diode D1 is connected to the D1 terminal of transistor Q3, and the D1 terminal of transistor Q3 is connected to the LEDY terminal of the LED lamp; the anode of diode D2 is connected to the D2 terminal of transistor Q3, and the D2 terminal of transistor Q3 is connected to the LEDW terminal of the LED lamp; the drain of MOSFET Q1 is connected to the PWM terminal of the main control chip U1.

[0050] The working principle of the above technical solution is as follows: In order to realize the LED short circuit protection circuit, this utility model proposes a step-down constant current circuit, a color temperature adjustment circuit and a short circuit protection circuit; the short circuit protection circuit is connected to the step-down constant current circuit and the color temperature adjustment circuit respectively; the short circuit protection circuit is used to transmit the short circuit signal in the color temperature adjustment circuit to the step-down constant current circuit when a component in the color temperature adjustment circuit is short-circuited, so that the step-down constant current circuit can perform the protection mechanism.

[0051] To achieve short-circuit protection, the short-circuit protection circuit proposed in this utility model includes a Zener diode Z1, a Zener diode Z2, a resistor R1, a resistor R2, a diode D1, a diode D2, a MOSFET Q1, and a capacitor C1.

[0052] To connect the short-circuit protection circuit with the step-down constant current circuit and the color temperature adjustment circuit, one end of capacitor C1 in this invention is connected to the cathode of Zener diode Z2, the other end of resistor R1, and one end of resistor R2; the other end of capacitor C1 is connected to the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1; the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1 are all grounded.

[0053] The other end of resistor R1 is connected to the gate of MOSFET Q1;

[0054] One end of resistor R1 is connected to the anode of Zener diode Z1; the cathode of Zener diode Z1 is connected to the cathodes of diode D1 and diode D2 respectively.

[0055] By connecting the anode of diode D1 to the D1 terminal of transistor Q3, and connecting the D1 terminal of transistor Q3 to the LEDY terminal of the LED lamp; connecting the anode of diode D2 to the D2 terminal of transistor Q3, and connecting the D2 terminal of transistor Q3 to the LEDW terminal of the LED lamp; and connecting the drain of MOSFET Q1 to the PWM terminal of the main control chip U1, the short-circuit protection circuit and the color temperature adjustment circuit can be connected.

[0056] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the circuit can be cut off in a very short time, effectively preventing the device from being damaged; and by adjusting the device parameters in the circuit, the effect of preventing false alarms can be achieved; the proposed short-circuit protection circuit can protect the circuit; by connecting the short-circuit protection circuit with the color temperature adjustment circuit, the short-circuit protection function can be easily realized.

[0057] In one embodiment, the step-down constant current circuit includes a main control chip U1, resistors R3, R4, R5, R6, R7, R8, R9, and R10, capacitors C2, C3, C4, C5, C6, and C7, transistor Q2, inductors L1 and L2, and diode D3.

[0058] like Figure 3 As shown, one end of resistor R3 is connected to one end of capacitor C2; the other end of capacitor C2 is grounded; one end of capacitor C2 is connected to one end of resistor R4, one end of resistor R5 and one end of capacitor C3 respectively; the other ends of resistor R4, resistor R5 and capacitor C3 are all connected to the positive terminal of the LED.

[0059] The other end of resistor R3 is connected to the VCC terminal of the main control chip U1;

[0060] One end of capacitor C3 is connected to the CSP terminal of the main control chip U1;

[0061] The other end of capacitor C3 is connected to the CSN terminal of the main control chip U1;

[0062] One end of resistor R6, one end of resistor R7, and one end of capacitor C4 are all connected to voltage regulator VREF;

[0063] The VREF terminal of the main control chip U1 is connected to the voltage regulator VREF;

[0064] The other end of resistor R7 is connected to one end of resistor R8 and one end of capacitor C5, respectively.

[0065] One end of capacitor C5 is connected to the ADIM terminal of the main control chip U1;

[0066] One end of capacitor C5 is connected to the ADIM terminal of the main control chip U1;

[0067] The other end of resistor R3 is connected to one end of capacitor C6;

[0068] One end of capacitor C7 is connected to the PWM terminal of the main control chip U1;

[0069] One end of resistor R9 is connected to the GATE terminal of the main control chip U1;

[0070] The other end of resistor R9 is connected to one end of resistor R10 and the gate of transistor Q2.

[0071] The drain of transistor Q2 is connected to the anode of diode D3; the cathode of diode D3 is connected to the CSP terminal of the main control chip U1.

[0072] The other ends of resistor R6, resistor R8, capacitor C4, capacitor C5, capacitor C6, capacitor C7, resistor R10, and the source of transistor Q2 are all grounded.

[0073] The anode of diode D3 is connected to one end of inductor L1, and the other end of inductor L1 is connected to one end of inductor L2.

[0074] The working principle of the above technical solution is as follows: In order to realize the function of the step-down constant current circuit, the step-down constant current circuit of this utility model includes a main control chip U1, resistors R3, R4, R5, R6, R7, R8, R9, R10, capacitors C2, C3, C4, C5, C6, C7, transistor Q2, inductors L1 and L2, and diode D3.

[0075] To achieve the function of the step-down constant current circuit, the component structure needs to be connected. The component connection of the step-down constant current circuit in this utility model is as follows: one end of resistor R3 is connected to one end of capacitor C2; the other end of capacitor C2 is grounded; one end of capacitor C2 is connected to one end of resistor R4, one end of resistor R5 and one end of capacitor C3 respectively; the other ends of resistor R4, the other end of resistor R5 and the other end of capacitor C3 are all connected to the positive terminal of the LED.

[0076] The other end of resistor R3 is connected to the VCC terminal of the main control chip U1;

[0077] One end of capacitor C3 is connected to the CSP terminal of the main control chip U1;

[0078] The other end of capacitor C3 is connected to the CSN terminal of the main control chip U1;

[0079] One end of resistor R6, one end of resistor R7, and one end of capacitor C4 are all connected to voltage regulator VREF;

[0080] The VREF terminal of the main control chip U1 is connected to the voltage regulator VREF;

[0081] The other end of resistor R7 is connected to one end of resistor R8 and one end of capacitor C5, respectively.

[0082] One end of capacitor C5 is connected to the ADIM terminal of the main control chip U1;

[0083] The other end of resistor R3 is connected to one end of capacitor C6;

[0084] One end of capacitor C7 is connected to the PWM terminal of the main control chip U1;

[0085] One end of resistor R9 is connected to the GATE terminal of the main control chip U1;

[0086] The other end of resistor R9 is connected to one end of resistor R10 and the gate of transistor Q2.

[0087] The drain of transistor Q2 is connected to the anode of diode D3; the cathode of diode D3 is connected to the CSP terminal of the main control chip U1.

[0088] The other ends of resistor R6, resistor R8, capacitor C4, capacitor C5, capacitor C6, capacitor C7, resistor R10, and the source of transistor Q2 are all grounded.

[0089] The anode of diode D3 is connected to one end of inductor L1, and the other end of inductor L1 is connected to one end of inductor L2.

[0090] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the detection of current signal can be realized through the step-down constant current circuit; by connecting the components in the step-down constant current circuit, the function of the step-down constant current circuit can be guaranteed.

[0091] In one embodiment, such as Figure 4 As shown, the color temperature adjustment circuit includes resistors R11, R12, R13, R14, R15, and R16, capacitors C8 and C9, a main control chip U3, and transistor Q3. The G2 terminal of transistor Q3 is connected to one end of resistor R11 and one end of resistor R12. The G1 terminal of transistor Q3 is connected to the other end of resistor R13 and one end of resistor R14. The S1 terminal of transistor Q3 is connected to one end of resistor R13. The other end of resistor R12 is connected to the D1 terminal of the main control chip U3. The other end of resistor R14 is connected to the D2 terminal of the main control chip U3. One end of capacitor C8 is connected to the HV terminal of the main control chip U3. The other end of capacitor C8 is connected to the VS terminal of the main control chip U3. One end of resistor R15 is connected to the HV terminal of the main control chip U3. The other end of resistor R15 is connected to a 48V power supply. The VCC terminal of the main control chip U3 is connected to one end of capacitor C9 and one end of resistor R16. The other end of capacitor C9 is grounded.

[0092] The working principle of the above technical solution is as follows: In order to achieve the color temperature change of the LED light, a color temperature adjustment circuit is required. The color temperature adjustment circuit in this utility model includes resistors R11, R12, R13, R14, R15, and R16, capacitors C8 and C9, a main control chip U3, and a transistor Q3; the G2 terminal of transistor Q3 is connected to one end of resistor R11 and one end of resistor R12 respectively; the G1 terminal of transistor Q3 is connected to the other end of resistor R13 and one end of resistor R14; the S1 terminal of transistor Q3... One end of resistor R13 is connected to the other end of resistor R12; the other end of resistor R14 is connected to the D1 terminal of main control chip U3; one end of capacitor C8 is connected to the HV terminal of main control chip U3; the other end of capacitor C8 is connected to the VS terminal of main control chip U3; one end of resistor R15 is connected to the HV terminal of main control chip U3; the other end of resistor R15 is connected to the 48V power supply; the VCC terminal of main control chip U3 is connected to one end of capacitor C9 and one end of resistor R16 respectively; the other end of capacitor C9 is grounded.

[0093] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the function of the color temperature adjustment circuit can be realized through the color temperature adjustment circuit.

[0094] In one embodiment, the other end of resistor R16 is connected to the VCC terminal of main control chip U1; the VS terminal of main control chip U3 is connected to the other end of inductor L2.

[0095] The working principle of the above technical solution is as follows: In order to realize the connection between the step-down constant current circuit and the color temperature adjustment circuit, this utility model connects the other end of the resistor R16 to the VCC terminal of the main control chip U1; and connects the VS terminal of the main control chip U3 to the other end of the inductor L2.

[0096] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, the function of the color temperature adjustment circuit can be realized through the connection of the step-down constant current circuit and the color temperature adjustment circuit.

[0097] In one embodiment, capacitor C1 is also used to skip the brief overshoot period of about 400ms that exists during normal power-on by charging it, so as to prevent false protection.

[0098] Resistors R1 and R2 are resistors with adjustable sensitivity;

[0099] When the main control chip U1 enters the short-circuit protection state, it can prevent transistor Q3 from overheating and being damaged.

[0100] The working principle of the above technical solution is as follows: the capacitor C1 in this utility model is also used to skip the short overshoot period of about 400ms that exists during normal power-on by charging it, so as to prevent false protection; resistors R1 and R2 are resistors with adjustable sensitivity; when the main control chip U1 enters the short circuit protection working state, it can prevent the transistor Q3 from overheating and being damaged.

[0101] The beneficial effects of the above technical solution are as follows: by adopting the solution provided in this embodiment, through the realization of the charging function of capacitor C1 and the adjustment of the resistance values ​​of resistors R1 and R2, false protection phenomena can be prevented and the function of protecting transistor Q3 can be protected.

[0102] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An LED short-circuit protection circuit, characterized in that, include: The circuit includes a step-down constant current circuit, a color temperature adjustment circuit, and a short-circuit protection circuit. The short-circuit protection circuit is connected to both the step-down constant current circuit and the color temperature adjustment circuit. When a short circuit occurs in a component of the color temperature adjustment circuit, the short-circuit protection circuit transmits the short-circuit signal from the color temperature adjustment circuit to the step-down constant current circuit, so that the step-down constant current circuit can execute the protection mechanism. The short-circuit protection circuit includes Zener diode Z1, Zener diode Z2, resistor R1, resistor R2, diode D1, diode D2, MOSFET Q1, and capacitor C1; One end of capacitor C1 is connected to the cathode of Zener diode Z2, the other end of resistor R1, and one end of resistor R2; the other end of capacitor C1 is connected to the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1; the anode of Zener diode Z2, the other end of resistor R2, and the source of MOSFET Q1 are all grounded. The other end of resistor R1 is connected to the gate of MOSFET Q1; One end of resistor R1 is connected to the anode of Zener diode Z1; the cathode of Zener diode Z1 is connected to the cathodes of diode D1 and diode D2 respectively. The anode of diode D1 is connected to the D1 terminal of transistor Q3, and the D1 terminal of transistor Q3 is connected to the LEDY terminal of the LED lamp; the anode of diode D2 is connected to the D2 terminal of transistor Q3, and the D2 terminal of transistor Q3 is connected to the LEDW terminal of the LED lamp; the drain of MOSFET Q1 is connected to the PWM terminal of the main control chip U1.

2. The LED short-circuit protection circuit according to claim 1, characterized in that, The step-down constant current circuit includes a main control chip U1, resistors R3, R4, R5, R6, R7, R8, R9, R10, capacitors C2, C3, C4, C5, C6, C7, transistor Q2, inductors L1 and L2, and diode D3. One end of resistor R3 is connected to one end of capacitor C2; the other end of capacitor C2 is grounded; one end of capacitor C2 is connected to one end of resistor R4, one end of resistor R5 and one end of capacitor C3 respectively; the other ends of resistor R4, resistor R5 and capacitor C3 are all connected to the positive terminal of the LED. The other end of resistor R3 is connected to the VCC terminal of the main control chip U1; One end of capacitor C3 is connected to the CSP terminal of the main control chip U1; The other end of capacitor C3 is connected to the CSN terminal of the main control chip U1; One end of resistor R6, one end of resistor R7, and one end of capacitor C4 are all connected to voltage regulator VREF; The VREF terminal of the main control chip U1 is connected to the voltage regulator VREF; The other end of resistor R7 is connected to one end of resistor R8 and one end of capacitor C5, respectively. The other end of resistor R3 is connected to one end of capacitor C6; One end of capacitor C7 is connected to the PWM terminal of the main control chip U1; One end of resistor R9 is connected to the GATE terminal of the main control chip U1; The other end of resistor R9 is connected to one end of resistor R10 and the gate of transistor Q2. The drain of transistor Q2 is connected to the anode of diode D3; the cathode of diode D3 is connected to the CSP terminal of the main control chip U1. The other ends of resistor R6, resistor R8, capacitor C4, capacitor C5, capacitor C6, capacitor C7, resistor R10, and the source of transistor Q2 are all grounded. The anode of diode D3 is connected to one end of inductor L1, and the other end of inductor L1 is connected to one end of inductor L2.

3. The LED short-circuit protection circuit according to claim 1, characterized in that, The color temperature adjustment circuit includes resistors R11, R12, R13, R14, R15, and R16, capacitors C8 and C9, main control chip U3, and transistor Q3. The G2 terminal of transistor Q3 is connected to one end of resistor R11 and one end of resistor R12, respectively; The G1 terminal of transistor Q3 is connected to the other end of resistor R13 and one end of resistor R14; the S1 terminal of transistor Q3 is connected to one end of resistor R13; the other end of resistor R12 is connected to the D1 terminal of main control chip U3; the other end of resistor R14 is connected to the D2 terminal of main control chip U3; one end of capacitor C8 is connected to the HV terminal of main control chip U3; the other end of capacitor C8 is connected to the VS terminal of main control chip U3; one end of resistor R15 is connected to the HV terminal of main control chip U3; the other end of resistor R15 is connected to a 48V power supply; the VCC terminal of main control chip U3 is connected to one end of capacitor C9 and one end of resistor R16; the other end of capacitor C9 is grounded.

4. The LED short-circuit protection circuit according to claim 3, characterized in that, The other end of resistor R16 is connected to the VCC terminal of the main control chip U1; the VS terminal of the main control chip U3 is connected to the other end of inductor L2.

5. The LED short-circuit protection circuit according to claim 1, characterized in that, Capacitor C1 is also used to skip the brief overshoot period of about 400ms that exists during normal power-on by charging it, so as to prevent false protection. Resistors R1 and R2 are resistors with adjustable sensitivity; When the main control chip U1 enters the short-circuit protection state, it can prevent transistor Q3 from overheating and being damaged.

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