Power supply circuit and lamp

Abstract

This utility model discloses a power supply circuit and a lamp. The power supply circuit includes: a main power supply circuit, an auxiliary power supply circuit, a chip power supply circuit, a switching circuit, and a power protection circuit. The input terminal of the auxiliary power supply circuit is connected to a first DC power source, and its output terminal outputs a second DC power source to the chip power supply circuit. The output terminal of the chip power supply circuit outputs chip power to the switching circuit, and the output terminal of the switching circuit is connected to the power supply terminal of the control chip of the main power supply circuit. The power protection circuit is connected to the controlled terminal of the switching circuit and is used to control the switching circuit to disconnect when an abnormality is detected in the load circuit, thereby cutting off the power supply to the control chip of the main power supply circuit. This utility model improves the safety of the power supply circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of switch power supplies, in particular to a power supply circuit and a lamp. Background Art

[0002] Electronic products currently on the market are generally powered by switching power supplies, and then equipped with subsequent application circuits. Once a problem occurs in the application circuit, it will cause collateral damage to the power circuit, and in severe cases, it will cause a very serious safety accident. Summary of the invention

[0003] The main purpose of the utility model is to provide a power supply circuit and a lamp, which can solve the problem that the existing power supply circuit is easy to burn out when the load circuit fails.

[0004] The present application provides a power supply circuit, which includes a main power supply circuit, and the power supply circuit also includes:

[0005] An auxiliary power supply circuit, the input end of which is connected to a first DC power supply, and the output end of which outputs a second DC power supply;

[0006] A chip power supply circuit, the input end of which is connected to the output end of the auxiliary power supply circuit, and the output end of the chip power supply circuit outputs the chip power supply;

[0007] a switch circuit, wherein the input end is connected to the chip power supply, and the output end of the switch circuit is connected to the power supply end of the control chip of the main power circuit; and

[0008] A power protection circuit is connected to the controlled end of the switch circuit, and is used to control the switch circuit to disconnect when an abnormality in the load circuit is detected, so as to cut off the power supply of the control chip of the main power circuit.

[0009] In one embodiment, the auxiliary power supply circuit includes:

[0010] A primary circuit and a secondary circuit, the primary circuit outputs the second DC power supply, the secondary circuit outputs a third DC power supply, and the third DC power supply is isolated from the second DC power supply.

[0011] In one embodiment, the power protection circuit includes:

[0012] A primary trigger circuit, the input end of which is connected to a disconnection control signal of the switch circuit, and the output end of the primary trigger circuit is connected to a controlled end of the switch circuit;

[0013] A first control circuit is connected to the controlled end of the primary trigger circuit, and the first control circuit is used to control the primary trigger circuit to be turned on when an abnormality in the load circuit is detected, so as to control the switch circuit to be turned off and cut off the power supply of the control chip of the main power supply circuit; wherein,

[0014] The power supply end of the first control circuit is connected to the primary circuit of the auxiliary power supply circuit to access the second DC power supply.

[0015] In one embodiment, the primary trigger circuit comprises:

[0016] A first switch tube, a first resistor, and a first capacitor; wherein the input end of the first switch tube is grounded, the output end of the first switch tube is connected to one end of the first resistor, and the other end of the first resistor is connected to the controlled end of the switch circuit; one end of the first capacitor is connected to the output end of the first switch tube, and the other end of the first capacitor is grounded.

[0017] In one embodiment, the power protection circuit includes:

[0018] A secondary trigger circuit, the input end of which is connected to the disconnection control signal of the switch circuit, and the output end of the secondary trigger circuit is connected to the controlled end of the switch circuit; wherein the controlled end of the secondary trigger circuit is isolated from its input end and its output end;

[0019] a second control circuit connected to the controlled end of the secondary trigger circuit, and configured to control the secondary trigger circuit to conduct when an abnormality in the load circuit is detected, so as to control the switch circuit to be disconnected, thereby cutting off the power supply of the control chip of the main power supply circuit;

[0020] Wherein, the power supply end of the second control circuit is connected to the secondary circuit of the auxiliary power supply circuit to access the third DC power supply.

[0021] In one embodiment, the secondary trigger circuit includes: a second resistor, a third resistor, a fourth resistor, a second capacitor, a third capacitor, an optical coupler, and a second switch tube; wherein,

[0022] The input end of the optical coupler is grounded, the output end of the optical coupler is connected to one end of the second resistor, and the other end of the second resistor is connected to the controlled end of the switch circuit; the anode of the optical coupler is connected to one end of the third resistor, and the other end of the third resistor is used to connect to a third DC power supply;

[0023] One end of the fourth resistor is connected to the anode of the optocoupler, the other end of the fourth resistor is connected to the cathode of the optocoupler and the output end of the second switch tube, and the input end of the second switch tube is grounded;

[0024] One end of the third capacitor is connected to the output end of the second switch tube, and the other end of the third capacitor is grounded.

[0025] In one embodiment, the power protection circuit includes:

[0026] A primary-secondary combined trigger circuit, the input end of which is connected to the disconnection control signal of the switch circuit, the output end of the primary-secondary combined trigger circuit is connected to the controlled end of the switch circuit, the primary-secondary combined trigger circuit comprises a first controlled end and a second controlled end, wherein the second controlled end is isolated from the input end and the output end of the primary-secondary combined trigger circuit;

[0027] a third control circuit connected to the first controlled end of the primary-secondary trigger circuit, and used to control the primary-secondary combined trigger circuit to conduct when an abnormality in the load circuit is detected, so as to control the switch circuit to be disconnected and cut off the power supply of the control chip of the main power supply circuit; wherein the power supply end of the third control circuit is connected to the primary circuit of the auxiliary power supply circuit to access the second DC power supply;

[0028] A fourth control circuit is connected to the controlled end of the primary-secondary combined trigger circuit. The fourth control circuit is used to control the primary-secondary combined trigger circuit to be turned on when an abnormality in the load circuit is detected, so as to control the switch circuit to be disconnected and cut off the power supply of the control chip of the main power supply circuit; wherein the power supply end of the fourth control circuit is connected to the secondary circuit of the auxiliary power supply circuit to access the third DC power supply.

[0029] In one embodiment, the switch circuit comprises:

[0030] A fifth resistor, a fourth capacitor, a fifth capacitor, a third switch tube, and a first voltage regulator tube; wherein, the input end of the third switch tube is connected to the second DC power supply, the output end of the third switch tube is connected to the power supply end of the control chip of the main power supply circuit, and the controlled end of the third switch tube is connected to the input end of the third switch tube through the fifth resistor; the controlled end of the third switch tube is the controlled end of the switch circuit; the anode of the first voltage regulator tube is grounded, and the cathode of the first voltage regulator tube is connected to the controlled end of the third switch tube; one end of the fourth capacitor is connected to the output end of the third switch tube, and the other end of the fourth capacitor is grounded; one end of the fifth capacitor is connected to the cathode of the first voltage regulator tube, and the other end of the fifth capacitor is grounded.

[0031] In one embodiment, the chip power supply circuit includes:

[0032] A sixth resistor, a sixth capacitor, a seventh capacitor, a second voltage regulator tube, and a fourth switch tube; wherein the input end of the fourth switch tube is connected to the first DC power supply, the output end of the fourth switch tube outputs the second DC power supply, and the input end of the fourth switch tube is connected to the controlled end of the fourth switch tube through the sixth resistor; the cathode of the second voltage regulator tube is connected to the controlled end of the fourth switch tube, and the anode of the second voltage regulator tube is grounded; one end of the sixth capacitor is connected to the cathode of the second voltage regulator tube, and the other end of the sixth capacitor is grounded; one end of the seventh capacitor is connected to the output end of the fourth switch tube, and the other end of the seventh capacitor is grounded.

[0033] The present application also proposes a lamp, which includes: an LED lamp, and the above-mentioned power supply circuit; wherein the output end of the main power supply circuit of the power supply circuit is connected to the power supply end of the LED lamp.

[0034] The present application utilizes an auxiliary power supply circuit and a chip power supply circuit to generate a chip power supply to supply power to the control chip of the main power supply circuit, and adds a switch circuit and a power supply protection circuit. The input end of the switch circuit is connected to the chip power supply, and the output end of the switch circuit is connected to the power supply end of the control chip of the main power supply circuit; the power supply protection circuit controls the switch circuit to disconnect when an abnormality in the load circuit is detected, so as to cut off the power supply to the control chip of the main power supply circuit. The main power supply circuit stops working, thereby solving the problem that the main power supply circuit is easily burned. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0036] Figure 1 It is a circuit block diagram of an embodiment of the power supply circuit of the utility model;

[0037] Figure 2 It is a schematic diagram of an auxiliary power supply circuit of an embodiment of the power supply circuit of the utility model;

[0038] Figure 3 It is a schematic diagram of a switch circuit and a power protection circuit of an embodiment of a power circuit of the utility model;

[0039] Figure 4 It is a schematic diagram of a switch circuit and a power protection circuit of another embodiment of the power circuit of the utility model;

[0040] Figure 5 It is a schematic diagram of a switch circuit and a power protection circuit of another embodiment of the power circuit of the utility model;

[0041] Figure 6 It is a schematic diagram of a chip power supply circuit of an embodiment of the power supply circuit of the utility model.

[0042] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0044] Reference Figure 1 In one embodiment, the power circuit includes a main power circuit 60, which may be an isolated switching power circuit or a non-isolated switching power circuit, which is not limited here. The main power circuit 60 may provide power supply for the load circuit, and the load circuit 70 may refer to an LED lamp or other power-consuming equipment that needs power supply.

[0045] To improve the safety of the power circuit, refer to Figure 1 In one embodiment, the power supply circuit of the present application further includes: an auxiliary power supply circuit 20 , a chip power supply circuit 30 , a switch circuit 50 and a power protection circuit 40 .

[0046] The input end of the auxiliary power supply circuit 20 is connected to the first DC power supply HV+, and the output end of the auxiliary power supply circuit 20 outputs the second DC power supply VM+; the input end of the chip power supply circuit 30 is connected to the output end of the auxiliary power supply circuit 20, and the output end of the chip power supply circuit 30 outputs the chip power supply VCC1+; the input end of the switch circuit 50 is connected to the chip power supply VCC1+, and the output end of the switch circuit 50 is connected to the power supply end of the control chip of the main power supply circuit 60; the power protection circuit 40 is connected to the controlled end of the switch circuit 50, and the power protection circuit 40 is used to control the switch circuit 50 to disconnect when an abnormality is detected in the load circuit 70, so as to cut off the power supply to the control chip of the main power supply circuit 60.

[0047] In this embodiment, the power supply circuit may further include a rectifier filter circuit 10, which is used to convert the external AC power supply into a first DC power supply HV+, and output it to the auxiliary power supply circuit 20 and the main power supply circuit 60. The auxiliary power supply circuit 20 can convert the first DC power supply HV+ into a second DC power supply VM+, as well as a third DC power supply V2+, a fourth DC power supply V1+, etc. with different output voltages. The chip power supply circuit 30 may be a linear voltage regulator circuit, which converts the second DC power supply VM+ into a more stable chip power supply VCC1+.

[0048] The power supply protection circuit 40 may include an abnormality detection circuit, such as overvoltage detection, overcurrent detection, overtemperature detection, etc., and a control circuit. When the control circuit detects that the load circuit 70 is abnormal, the control circuit controls the switch circuit 50 to disconnect, cuts off the power supply of the control chip of the main power supply circuit 60, and improves the safety of the main power supply circuit 60.

[0049] The present application utilizes the auxiliary power supply circuit 20 and the chip power supply circuit 30 to generate a chip power supply VCC1+ to power the control chip of the main power supply circuit 60, and adds a switch circuit 50 and a power protection circuit 40. The input end of the switch circuit 50 is connected to the chip power supply VCC1+, and the output end of the switch circuit 50 is connected to the power supply end of the control chip of the main power supply circuit 60; the power protection circuit 40 controls the switch circuit 50 to disconnect when an abnormality is detected in the load circuit 70, so as to cut off the power supply of the control chip of the main power supply circuit 60. The main power supply circuit 60 stops working, thereby solving the problem that the main power supply circuit 60 is easily burned. In some embodiments, it is also possible to choose to cut off the power supply of the control chip of the load circuit 70.

[0050] Reference Figure 2 In one embodiment, the auxiliary power supply circuit 20 includes: a primary circuit 21 and a secondary circuit 22, the primary circuit 21 outputs the second DC power supply VM+, the secondary circuit 22 outputs a third DC power supply V2+, and the third DC power supply V2+ is isolated from the second DC power supply VM+.

[0051] In this embodiment, the rectifying and filtering circuit 10 outputs the first DC power source HV+HV+ to the primary circuit 21 .

[0052] The primary circuit 21 includes: a constant current control chip U1 and its corresponding peripheral circuits. Exemplarily, the constant current control chip U1 can be a PSR constant voltage control chip, the PSR constant voltage control chip generates a switching signal inside, the built-in field effect transistor switch performs a switching action, and a switching square wave is generated from the 5th and 6th pins of the PSR constant voltage control chip, which acts on the 1-3 pin coils of the transformer T1, so that each group of coils generates an output voltage.

[0053] The secondary circuit 22 is connected to the secondary of the transformer T1, outputs a third DC power source V2+, and can also output a fourth DC power source V1+ to supply power to other devices with different voltage requirements.

[0054] Reference Figures 3 to 5 The switch circuit 50 has not only a switch function but also other functions, such as voltage stabilization. In one embodiment, the switch circuit 50 is a linear voltage stabilization circuit. After the chip power supply VCC1++ is stabilized, it becomes a stabilized chip power supply VCC2+.

[0055] Specifically, in this embodiment, the switch circuit 50 includes: a fifth resistor R5, a fourth capacitor C4, a fifth capacitor C5, a third switch tube Q3, and a first voltage regulator tube ZD1; wherein,

[0056] The input end of the third switch tube Q3 is connected to the second DC power supply VM+, the output end of the third switch tube Q3 is connected to the power supply end of the control chip of the main power supply circuit 60, and the controlled end of the third switch tube Q3 is connected to the input end of the third switch tube Q3 through the fifth resistor R5; the anode of the first voltage regulator tube ZD1 is grounded, and the cathode of the first voltage regulator tube ZD1 is connected to the controlled end of the third switch tube Q3; one end of the fourth capacitor C4 is connected to the output end of the third switch tube Q3, and the other end of the fourth capacitor C4 is grounded; one end of the fifth capacitor C5 is connected to the cathode of the first voltage regulator tube ZD1, and the other end of the fifth capacitor C5 is grounded.

[0057] In this embodiment, the controlled end of the third switch tube Q3 is the controlled end of the switch circuit 50. When the controlled end of the third switch tube Q3 receives a low level, the third switch tube Q3 is turned off, so that the entire switch circuit 50 is disconnected and stops outputting the chip power supply VCC1+.

[0058] With regard to the specific implementation of the power protection circuit 40 , the present application provides the following embodiments.

[0059] Reference Figure 3 In one embodiment, the power protection circuit 40 includes:

[0060] The primary trigger circuit 41 has an input terminal connected to a disconnection control signal of the switch circuit 50, and an output terminal of the primary trigger circuit 41 is connected to a controlled terminal of the switch circuit 50; a first control circuit (not shown) is connected to the controlled terminal of the primary trigger circuit 41, and the first control circuit is used to output a primary control signal IN2 to control the primary trigger circuit 41 to conduct when an abnormality of the load circuit 70 is detected, so as to control the switch circuit 50 to disconnect and cut off the power supply of the control chip of the main power supply circuit 60; wherein,

[0061] The power supply end of the first control circuit is connected to the primary circuit 21 of the auxiliary power supply circuit 20 to access the second DC power supply VM+.

[0062] In this embodiment, the primary trigger circuit 41 is a switching circuit. The first control circuit is connected to the abnormality detection circuit to receive an abnormality detection signal. The first control circuit is powered by the primary circuit 21 of the auxiliary power supply circuit 20. When the primary circuit 21 of the auxiliary power supply circuit 20 is not abnormal, the first control circuit can output a primary control signal IN2 (a high-level signal in this embodiment) to control the operation of the primary trigger circuit 41 based on the abnormal situation. The first control circuit does not need to be isolated from the primary trigger circuit 41, thereby reducing costs.

[0063] For example, refer to Figure 3 In this embodiment, the primary trigger circuit 41 includes: a first switch tube Q1, a first resistor R1, and a first capacitor C1; wherein the input end of the first switch tube Q1 is grounded, the output end of the first switch tube Q1 is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the controlled end of the switch circuit 50; one end of the first capacitor C1 is connected to the output end of the first switch tube Q1, and the other end of the first capacitor C1 is grounded.

[0064] In this embodiment, when the first switch tube Q1 is turned on, the level of the controlled end of the third switch tube Q3 is pulled down, so that the third switch tube Q3 is turned off.

[0065] Reference Figure 4 In one embodiment, the power protection circuit 40 includes: a secondary trigger circuit 42 and a second control circuit (not shown), wherein the power supply end of the second control circuit is connected to the secondary circuit 22 of the auxiliary power supply circuit 20 to access the third DC power supply V2+.

[0066] The input end of the secondary trigger circuit 42 is connected to the disconnection control signal of the switch circuit 50, and the output end of the secondary trigger circuit 42 is connected to the controlled end of the switch circuit 50; wherein the controlled end of the secondary trigger circuit 42 is isolated from its input end and its output end;

[0067] The second control circuit is connected to the controlled end of the secondary trigger circuit 42. When an abnormality is detected in the load circuit 70, the second control circuit is used to output a secondary control signal IN1 to control the secondary trigger circuit 42 to turn on, so as to control the switch circuit 50 to disconnect and cut off the power supply to the control chip of the main power supply circuit 60.

[0068] Exemplarily, in this embodiment, the secondary trigger circuit 42 includes: a second resistor R2, a third resistor R3, a fourth resistor R4, a second capacitor C2, a third capacitor C3, an optocoupler U2, and a second switch tube Q2; wherein, the input end of the optocoupler U2 is grounded, the output end of the optocoupler U2 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the controlled end of the switch circuit 50; the anode of the optocoupler U2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is used to access a third DC power supply V2+; one end of the fourth resistor R4 is connected to the anode of the optocoupler U2, the other end of the fourth resistor R4 is connected to the cathode of the optocoupler U2 and the output end of the second switch tube Q2, and the input end of the second switch tube Q2 is grounded; one end of the third capacitor C3 is connected to the output end of the second switch tube Q2, and the other end of the third capacitor C3 is grounded.

[0069] In this embodiment, when the second switch tube Q2 is turned on, the light emitting diode of the optocoupler U2 is turned on to control the conduction between its input end and output end, thereby lowering the level of the controlled end of the third switch tube Q3, so that the third switch tube Q3 is turned off.

[0070] Reference Figure 5 In one embodiment, the power protection circuit 40 includes: a primary-secondary combined trigger circuit, a third control circuit and a fourth control circuit.

[0071] A primary-secondary combined trigger circuit, the input end of which is connected to the disconnection control signal of the switch circuit 50, the output end of the primary-secondary combined trigger circuit is connected to the controlled end of the switch circuit 50, and the primary-secondary combined trigger circuit includes a first controlled end and a second controlled end, wherein the second controlled end is isolated from the input end and the output end of the primary-secondary combined trigger circuit;

[0072] The third control circuit (not shown) is connected to the first controlled end of the primary-secondary trigger circuit 42. The third control circuit is used to control the primary-secondary combined trigger circuit to be turned on when an abnormality is detected in the load circuit 70, so as to control the switch circuit 50 to be turned off, and cut off the power supply of the control chip of the main power circuit 60; wherein the power supply end of the third control circuit is connected to the primary circuit 21 of the auxiliary power circuit 20, so as to be connected to the second DC power supply VM+;

[0073] The fourth control circuit (not shown) is connected to the controlled end of the primary-secondary combined trigger circuit. The fourth control circuit is used to control the primary-secondary combined trigger circuit to be turned on when an abnormality is detected in the load circuit 70, so as to control the switch circuit 50 to be disconnected and cut off the power supply to the control chip of the main power supply circuit 60; wherein the power supply end of the fourth control circuit is connected to the secondary circuit 22 of the auxiliary power supply circuit 20 to access the third DC power supply V2+.

[0074] This embodiment is a combination of the primary trigger circuit 41 and the secondary trigger circuit 42, and the specific working principle is the same as the working principle of the primary trigger circuit 41 and the secondary trigger circuit 42. However, this embodiment only requires that the primary circuit 21 or the secondary circuit 22 of the auxiliary power supply circuit 20 is not damaged at the same time, so that at least one of the third control circuit and the fourth control circuit can work, and then when the load circuit 70 is abnormal, the switch circuit 50 is controlled to be disconnected, thereby improving safety.

[0075] Reference Figure 6 In one embodiment, the chip power supply circuit 30 includes: a sixth resistor R6, a sixth capacitor C6, a seventh capacitor C7, a second voltage regulator tube ZD2, and a fourth switch tube Q4; wherein the input end of the fourth switch tube Q4 is connected to the first DC power supply HV+, the output end of the fourth switch tube Q4 outputs the second DC power supply VM+, and the input end of the fourth switch tube Q4 is connected to the controlled end of the fourth switch tube Q4 through the sixth resistor R6; the cathode of the second voltage regulator tube ZD2 is connected to the controlled end of the fourth switch tube Q4, and the anode of the second voltage regulator tube ZD2 is grounded; one end of the sixth capacitor C6 is connected to the cathode of the second voltage regulator tube ZD2, and the other end of the sixth capacitor C6 is grounded; one end of the seventh capacitor C7 is connected to the output end of the fourth switch tube Q4, and the other end of the seventh capacitor C7 is grounded.

[0076] The present application also proposes a lamp, comprising: an LED lamp and the above-mentioned power circuit; wherein the output end of the main power circuit 60 of the power circuit is connected to the power supply end of the LED lamp. The lamp of this embodiment comprises the power circuit of the above-mentioned embodiment, and thus has the technical effect of the above-mentioned embodiment.

[0077] The above description is only an optional embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection of the present invention.

Claims

1. A power supply circuit, comprising a main power supply circuit, characterized in that: The power supply circuit also includes: An auxiliary power supply circuit, the input end of which is connected to a first DC power supply, and the output end of which outputs a second DC power supply; A chip power supply circuit, the input end of which is connected to the output end of the auxiliary power supply circuit, and the output end of the chip power supply circuit outputs the chip power supply; a switch circuit, wherein the input end is connected to the chip power supply, and the output end of the switch circuit is connected to the power supply end of the control chip of the main power circuit; and A power protection circuit is connected to the controlled end of the switch circuit, and is used to control the switch circuit to disconnect when an abnormality in the load circuit is detected, so as to cut off the power supply of the control chip of the main power circuit.

2. The power supply circuit according to claim 1, characterized in that The auxiliary power supply circuit comprises: A primary circuit and a secondary circuit, the primary circuit outputs the second DC power supply, the secondary circuit outputs a third DC power supply, and the third DC power supply is isolated from the second DC power supply.

3. The power supply circuit according to claim 2, characterized in that: The power protection circuit comprises: A primary trigger circuit, the input end of which is connected to a disconnection control signal of the switch circuit, and the output end of the primary trigger circuit is connected to a controlled end of the switch circuit; A first control circuit is connected to the controlled end of the primary trigger circuit, and the first control circuit is used to control the primary trigger circuit to be turned on when an abnormality in the load circuit is detected, so as to control the switch circuit to be turned off and cut off the power supply of the control chip of the main power supply circuit; wherein, The power supply end of the first control circuit is connected to the primary circuit of the auxiliary power supply circuit to access the second DC power supply.

4. The power supply circuit according to claim 3, characterized in that: The primary trigger circuit includes: a first switch tube, a first resistor, and a first capacitor; wherein, The input end of the first switch tube is grounded, the output end of the first switch tube is connected to one end of the first resistor, and the other end of the first resistor is connected to the controlled end of the switch circuit; one end of the first capacitor is connected to the output end of the first switch tube, and the other end of the first capacitor is grounded.

5. The power supply circuit according to claim 2, characterized in that: The power protection circuit comprises: A secondary trigger circuit, the input end of which is connected to the disconnection control signal of the switch circuit, and the output end of the secondary trigger circuit is connected to the controlled end of the switch circuit; wherein the controlled end of the secondary trigger circuit is isolated from its input end and its output end; a second control circuit connected to the controlled end of the secondary trigger circuit, and configured to control the secondary trigger circuit to conduct when an abnormality in the load circuit is detected, so as to control the switch circuit to be disconnected, thereby cutting off the power supply of the control chip of the main power supply circuit; Wherein, the power supply end of the second control circuit is connected to the secondary circuit of the auxiliary power supply circuit to access the third DC power supply.

6. The power supply circuit according to claim 5, characterized in that: The secondary trigger circuit includes: a second resistor, a third resistor, a fourth resistor, a second capacitor, a third capacitor, an optical coupler, and a second switch tube; wherein, The input end of the optical coupler is grounded, the output end of the optical coupler is connected to one end of the second resistor, and the other end of the second resistor is connected to the controlled end of the switch circuit; the anode of the optical coupler is connected to one end of the third resistor, and the other end of the third resistor is used to connect to a third DC power supply; One end of the fourth resistor is connected to the anode of the optocoupler, the other end of the fourth resistor is connected to the cathode of the optocoupler and the output end of the second switch tube, and the input end of the second switch tube is grounded; One end of the third capacitor is connected to the output end of the second switch tube, and the other end of the third capacitor is grounded.

7. The power supply circuit according to claim 2, characterized in that: The power protection circuit comprises: A primary-secondary combined trigger circuit, the input end of which is connected to the disconnection control signal of the switch circuit, the output end of the primary-secondary combined trigger circuit is connected to the controlled end of the switch circuit, the primary-secondary combined trigger circuit comprises a first controlled end and a second controlled end, wherein the second controlled end is isolated from the input end and the output end of the primary-secondary combined trigger circuit; a third control circuit connected to the first controlled end of the primary-secondary combined trigger circuit, and the third control circuit is used to control the primary-secondary combined trigger circuit to be turned on when an abnormality in the load circuit is detected, so as to control the switch circuit to be turned off and cut off the power supply of the control chip of the main power supply circuit; wherein the power supply end of the third control circuit is connected to the primary circuit of the auxiliary power supply circuit to access the second DC power supply; A fourth control circuit is connected to the controlled end of the primary-secondary combined trigger circuit. The fourth control circuit is used to control the primary-secondary combined trigger circuit to be turned on when an abnormality in the load circuit is detected, so as to control the switch circuit to be disconnected and cut off the power supply of the control chip of the main power supply circuit; wherein the power supply end of the fourth control circuit is connected to the secondary circuit of the auxiliary power supply circuit to access the third DC power supply.

8. The power supply circuit according to any one of claims 1 to 7, characterized in that: The switch circuit includes: a fifth resistor, a fourth capacitor, a fifth capacitor, a third switch tube, and a first voltage regulator tube; wherein, The input end of the third switch tube is connected to the second DC power supply, the output end of the third switch tube is connected to the power supply end of the control chip of the main power supply circuit, and the controlled end of the third switch tube is connected to the input end of the third switch tube through a fifth resistor; the controlled end of the third switch tube is the controlled end of the switch circuit; The anode of the first voltage regulator tube is grounded, and the cathode of the first voltage regulator tube is connected to the controlled end of the third switch tube; One end of the fourth capacitor is connected to the output end of the third switch tube, and the other end of the fourth capacitor is grounded; One end of the fifth capacitor is connected to the cathode of the first voltage regulator tube, and the other end of the fifth capacitor is grounded.

9. The power supply circuit according to claim 1, characterized in that: The chip power supply circuit includes: a sixth resistor, a sixth capacitor, a seventh capacitor, a second voltage regulator tube, and a fourth switch tube; wherein, The input end of the fourth switch tube is connected to the first DC power supply, the output end of the fourth switch tube outputs the second DC power supply, and the input end of the fourth switch tube is connected to the controlled end of the fourth switch tube through a sixth resistor; The cathode of the second voltage regulator tube is connected to the controlled end of the fourth switch tube, and the anode of the second voltage regulator tube is grounded; One end of the sixth capacitor is connected to the cathode of the second voltage regulator tube, and the other end of the sixth capacitor is grounded; One end of the seventh capacitor is connected to the output end of the fourth switch tube, and the other end of the seventh capacitor is grounded.

10. A lamp, characterized in that: The lamp comprises: An LED lamp, and a power supply circuit as described in any one of claims 1 to 9; wherein the output end of the main power supply circuit of the power supply circuit is connected to the power supply end of the LED lamp.

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