Multi-protection AC / DC dual-output power supply

Abstract

The utility model discloses a multi-protection AC / DC dual-output power supply comprising an AC input circuit, an AC output control circuit, a PFC DC power supply circuit, a DC output control circuit, a flyback switching power supply circuit, an input overvoltage / undervoltage protection circuit, an over-temperature protection circuit, an output short-circuit protection circuit and a master control circuit which are connected. The protection circuit has an input overvoltage protection function, an input under-voltage protection function, an output short-circuit protection function and an over-temperature protection function, and can effectively ensure the use safety of the whole circuit.

Description

Technical Field

[0001] This utility model relates to the field of power supply, and in particular to a multi-protection AC / DC dual-output power supply. Background Technology

[0002] To meet the demands of electrical loads (such as beauty and hairdressing equipment) for both direct current and alternating current, dual-output AC / DC power supplies have emerged on the market. However, existing dual-output AC / DC power supplies lack sufficient protection for the DC power supply, affecting the overall safety of the power supply.

[0003] In view of the above problems, it is necessary to study a multi-protection AC / DC dual-output power supply, which has the advantage of safe use. Utility Model Content

[0004] The purpose of this invention is to provide a multi-protection AC / DC dual-output power supply, which has the advantage of safe use.

[0005] To achieve the above objectives, the solution of this utility model is:

[0006] A multi-protection AC / DC dual-output power supply includes an AC input circuit, an AC output control circuit, a PFC DC power supply circuit, a DC output control circuit, a flyback switching power supply circuit, an input overvoltage / undervoltage protection circuit, an overtemperature protection circuit, an output short-circuit protection circuit, and a main control circuit. The AC input side of the AC output control circuit is connected to the AC output side of the AC input circuit. The AC input side of the PFC DC power supply circuit is connected to the AC output side of the AC input circuit. The DC input side of the DC output control circuit and the DC input side of the flyback switching power supply circuit are connected to the DC output side of the PFC DC power supply circuit. The two input sides of the input overvoltage / undervoltage protection circuit are respectively connected to the PFC DC power supply circuit. The AC input side of the circuit and the DC output side of the flyback switching power supply circuit are connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit. The input side of the output short-circuit protection circuit is connected to the DC output control circuit, and the output side of the output short-circuit protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit. The over-temperature protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit through the input over-voltage and under-voltage protection circuit. The main control circuit is connected to the PFC DC power supply circuit and controls whether the PFC DC power supply circuit works. The main control circuit is also connected to the AC output control circuit and controls the on / off state of the AC output control circuit.

[0007] The AC output control circuit includes a relay RL1 and an AC output port J0. The AC input terminal of the output circuit of the relay RL1 is connected to the AC1 terminal of the AC input circuit. The AC output terminal of the relay RL1 is connected to the L pin of the AC output port J0. The two DC control terminals of the relay RL1 are connected to the main control circuit. The N pin of the AC output port J0 is connected to the AC2 terminal of the AC input circuit.

[0008] The input overvoltage and undervoltage protection circuit includes an input undervoltage protection unit and an input overvoltage protection unit. The input undervoltage protection unit includes diodes D3, D4, and D16, resistors R15, R29, R32, R34, R62, R65, R67, R83, and R84, MOSFET Q13, and comparator COMP1. The anodes of diodes D3 and D4 are connected to the AC1- and AC2- terminals of the PFC DC power supply circuit, respectively, and the cathodes of diodes D3 and D4 are connected to the AC1- and AC2- terminals of the PFC DC power supply circuit. The negative terminal of resistor R4 is connected to the first terminal of resistor R29. The second terminal of resistor R29 is connected to the first terminals of resistors R15 and R34. The second terminal of resistor R34 and the first terminal of resistor R62 are connected to the DC output side of the flyback switching power supply circuit through a sampling unit. The second terminal of resistor R62 is grounded. The second terminal of resistor R15 is connected to the inverting input terminal of comparator COMP1. The non-inverting input terminal of comparator COMP1 is connected to the first terminals of resistors R65 and R67. The second terminal of resistor R65 is connected to the 2.5V power supply. The second terminal of resistor R67... The output terminal of comparator COMP1 is connected to the diode D16. The output terminal of comparator COMP1 is connected to the first terminal of resistor R84. The second terminal of resistor R84 is connected to the first terminal of resistor R83 and the gate of MOSFET Q13. The drain of MOSFET Q13 is connected to the VCC pin of boost controller U4. The input overvoltage protection unit includes resistors R63, R64, R66, R81, R82, diode D17, MOSFET Q11, and comparator COMP2. The first terminal of resistor R63 is connected to the flyback transistor via the sampling unit. On the DC output side of the switching power supply circuit, the second end of resistor R63 and the first end of resistor R64 are connected to the non-inverting input of comparator COMP2. The inverting input of comparator COMP2 is connected to the 2.5V power supply through resistor R66. The second end of resistor R64 is connected to the output of comparator COMP2 through diode D17. The output of comparator COMP2 is connected to the first end of resistor R82. The second end of resistor R82 is connected to the first end of resistor R81 and the gate of MOSFET Q11. The source of MOSFET Q11 is connected to the 15V SELV terminal of the flyback switching power supply circuit. The drain of MOSFET Q11 is connected to the second end of resistor R83 and the source of MOSFET Q13.

[0009] The input overvoltage and undervoltage protection circuit also includes a main control switch unit. The source of MOSFET Q13 is connected to the drain of MOSFET Q11 through the main control switch unit. The main control switch unit includes resistors R17, R18, and R36, and MOSFET Q2. The drain of MOSFET Q2 is connected to the source of MOSFET Q13. The source of MOSFET Q2 is connected to the drain of MOSFET Q11 through resistor R18. The gate of MOSFET Q2 is connected to the first terminal of resistor R17 and the first terminal of resistor R36. The second terminal of resistor R17 is connected to the drain of MOSFET Q11. The second terminal of resistor R36 is connected to the main control circuit.

[0010] The sampling unit includes resistor R60, resistor R62 and diode D15. The first end of resistor R60 is connected to the 15V terminal of the flyback switching power supply circuit. The second end of resistor R60 is connected to the positive terminal of diode D15. The negative terminal of diode D15 and the first end of resistor R62 are connected to the second end of resistor R34, the first end of resistor R62 and the first end of resistor R63. The second end of resistor R62 is grounded.

[0011] The over-temperature protection circuit includes resistors R7, R11, R61, R69, a thermistor TH1, and a comparator COMP3. The first end of resistor R7 is connected to the 15V terminal of the flyback switching power supply circuit. The second end of resistor R7 is connected to the first end of the thermistor TH1. The second end of the thermistor TH1 is connected to the first ends of resistors R11 and R61, and the non-inverting input of comparator COMP3. The second end of resistor R11 is grounded. The inverting input of comparator COMP3 is connected to a 2.5V power supply through resistor R69. The second end of resistor R61 is connected to the output of comparator COMP3. The output of comparator COMP3 is connected to the positive terminal of diode D15 in the sampling unit.

[0012] The output short-circuit protection circuit includes resistors R22, R70, R70A, R73, R74, and R75, diodes D13, D21, and D22, MOSFET Q14, transistor Q10, comparator U2B, and comparator COMP1. The inverting input of comparator U2B is connected to power supply VREF, and the non-inverting input is connected to the OCP terminal of the DC output control circuit. The output of comparator U2B is connected to the first terminal of resistor R72 and the inverting input of comparator COMP4 via diode D22. The second terminal of resistor R72 is grounded, and the non-inverting input of comparator COMP4 is connected to resistor R... The first terminal of resistor R70 is connected to the first terminal of resistor R70. The second terminal of resistor R70A is connected to a 2.5V power supply. The second terminal of resistor R70 is connected to the output terminal of comparator COMP4 through diode D21. The output terminal of comparator COMP4 is connected to the first terminal of resistor R73. The second terminal of resistor R73 is connected to the gate of MOSFET Q14. The source of MOSFET Q14 is grounded. The drain of MOSFET Q14 is connected to the first terminal of resistor R74 and the base of transistor Q10. The collector of transistor Q10 and the second terminal of resistor R74 are connected to the VCC pin of boost controller U4. The emitter of transistor Q10 is grounded through resistor R75, diode D13 and resistor R28.

[0013] The control terminal of the DC output control circuit is connected to the VCC pin of the boost controller U4.

[0014] By adopting the above scheme, this utility model can realize input overvoltage protection and input undervoltage protection functions through the input overvoltage and undervoltage protection circuit, output short circuit protection function through the output short circuit protection circuit, and overtemperature protection function through the overtemperature protection circuit. It can be seen that this utility model has rich protection functions and can effectively ensure the safety of the entire circuit. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the AC input circuit, DC output control circuit, and PFC DC power supply circuit of this utility model.

[0016] Figure 2 This is a circuit diagram of the AC output control circuit, flyback switching power supply circuit, main control circuit, and voltage divider circuit of this utility model.

[0017] Figure 3 This is a circuit diagram of the input overvoltage and undervoltage protection circuit of this utility model.

[0018] Figure 4 This is a circuit diagram of the over-temperature protection circuit and the output short-circuit protection circuit of this utility model. Detailed Implementation

[0019] To further explain the technical solution of this utility model, the following detailed description is provided through specific embodiments.

[0020] like Figures 1 to 4 As shown, this utility model discloses a multi-protection AC / DC dual-output power supply, which includes an AC input circuit, an AC output control circuit, a PFC DC power supply circuit, a DC output control circuit, a flyback switching power supply circuit, an input overvoltage / undervoltage protection circuit, an overtemperature protection circuit, an output short-circuit protection circuit, and a main control circuit. The AC input side of the AC output control circuit is connected to the AC output side of the AC input circuit; the AC input side of the PFC DC power supply circuit is connected to the AC output side of the AC input circuit; the DC input side of the DC output control circuit and the DC input side of the flyback switching power supply circuit are connected to the DC output side of the PFC DC power supply circuit; the two input sides of the input overvoltage / undervoltage protection circuit are respectively connected to the PFC DC power supply circuit. The AC input side of the PFC DC power supply circuit and the DC output side of the flyback switching power supply circuit are connected. The output side of the input overvoltage and undervoltage protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit. The input side of the output short-circuit protection circuit is connected to the DC output control circuit, and the output side of the output short-circuit protection circuit is also connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit. The over-temperature protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit through the input overvoltage and undervoltage protection circuit. The main control circuit is connected to the PFC DC power supply circuit and controls whether the PFC DC power supply circuit works. The main control circuit is also connected to the AC output control circuit and controls the on / off state of the AC output control circuit. The PFC DC power supply circuit can output 395V DC, and the flyback switching power supply circuit can output 15V DC.

[0021] In this invention, the input overvoltage and undervoltage protection circuits provide input overvoltage and undervoltage protection, the output short-circuit protection circuit provides output short-circuit protection, and the over-temperature protection circuit provides over-temperature protection. Therefore, this invention offers a wide range of protection functions, effectively ensuring the safe operation of the entire circuit.

[0022] In an embodiment of this utility model, the AC output control circuit includes a relay RL1 and an AC output port J0. The AC input terminal of the output circuit of the relay RL1 is connected to the AC1 terminal of the AC input circuit, the AC output terminal of the relay RL1 is connected to the L pin of the AC output port J0, the two DC control terminals of the relay RL1 are connected to the main control circuit, and the N pin of the AC output port J0 is connected to the AC2 terminal of the AC input circuit.

[0023] In an embodiment of this utility model, the input overvoltage and undervoltage protection circuit may include an input undervoltage protection unit and an input overvoltage protection unit; wherein, the input undervoltage protection unit includes diodes D3, D4, and D16, resistors R15, R29, R32, R34, R62, R65, R67, R83, and R84, a MOSFET Q13, and a comparator COMP1; the anodes of diodes D3 and D4 are respectively connected to the AC1- and AC2- terminals of the PFC DC power supply circuit. The negative terminals of diodes D3 and D4 are connected to the first terminal of resistor R29. The second terminal of resistor R29 is connected to the first terminals of resistors R15 and R34. The second terminal of resistor R34 and the first terminal of resistor R62 are connected to the DC output side of the flyback switching power supply circuit through a sampling unit. The second terminal of resistor R62 is grounded. The second terminal of resistor R15 is connected to the inverting input terminal of comparator COMP1. The non-inverting input terminal of comparator COMP1 is connected to the first terminals of resistors R65 and R67. The second terminal of resistor R65 is connected to a 2.5V power supply. The second terminal of resistor R67 is connected to the output terminal of comparator COMP1 via diode D16. The output terminal of comparator COMP1 is connected to the first terminal of resistor R84. The second terminal of resistor R84 is connected to the first terminal of resistor R83 and the gate of MOSFET Q13. The drain of MOSFET Q13 is connected to the VCC pin of boost controller U4. The input overvoltage protection unit includes resistors R63, R64, R66, R81, R82, diode D17, MOSFET Q11, and comparator COMP2. The first terminal of resistor R63 is connected to the sampling unit... Connecting to the DC output side of the flyback switching power supply circuit, the second end of resistor R63 and the first end of resistor R64 are connected to the non-inverting input of comparator COMP2. The inverting input of comparator COMP2 is connected to the 2.5V power supply through resistor R66. The second end of resistor R64 is connected to the output of comparator COMP2 through diode D17. The output of comparator COMP2 is connected to the first end of resistor R82. The second end of resistor R82 is connected to the first end of resistor R81 and the gate of MOSFET Q11. The source of MOSFET Q11 is connected to the 15V SELV terminal of the flyback switching power supply circuit. The drain of MOSFET Q11 is connected to the second end of resistor R83 and the source of MOSFET Q13.The working principle of the input overvoltage and undervoltage protection circuit is as follows: When the input undervoltage occurs, the comparator COMP1 of the input undervoltage protection unit controls the MOS transistor Q13 to turn off, thereby de-energizing the VCC pin of the boost controller U4, and thus stopping the PFC DC power supply circuit from working, thereby realizing the input undervoltage protection function; when the input overvoltage occurs, the comparator COMP2 of the input overvoltage protection unit controls the MOS transistor Q11 to turn off, thereby de-energizing the VCC pin of the boost controller U4, and thus stopping the PFC DC power supply circuit from working, thereby realizing the input overvoltage protection function.

[0024] In an embodiment of this invention, the input overvoltage and undervoltage protection circuit may further include a main control switch unit. The source of MOSFET Q13 is connected to the drain of MOSFET Q11 through the main control switch unit. The main control switch unit includes resistors R17, R18, and R36, and MOSFET Q2. The drain of MOSFET Q2 is connected to the source of MOSFET Q13, and the source of MOSFET Q2 is connected to the drain of MOSFET Q11 through resistor R18. The gate of MOSFET Q2 is connected to the first end of resistor R17 and the first end of resistor R36. The second end of resistor R17 is connected to the drain of MOSFET Q11, and the second end of resistor R36 is connected to the main control circuit. This configuration allows the main control circuit to control whether the PFC DC power supply circuit operates through the input overvoltage and undervoltage protection circuit. When the main control circuit controls MOSFET Q2 to conduct, the PFC DC power supply circuit can operate; when the main control circuit controls MOSFET Q2 to turn off, the PFC DC power supply circuit cannot operate.

[0025] In an embodiment of this utility model, the sampling unit may include resistor R60, resistor R62 and diode D15. The first end of resistor R60 is connected to the 15V terminal of the flyback switching power supply circuit, the second end of resistor R60 is connected to the positive terminal of diode D15, the negative terminal of diode D15 and the first end of resistor R62 are connected to the second end of resistor R34, the first end of resistor R62 and the first end of resistor R63, and the second end of resistor R62 is grounded.

[0026] In an embodiment of this utility model, the over-temperature protection circuit includes resistors R7, R11, R61, and R69, a thermistor TH1, and a comparator COMP3. The first end of resistor R7 is connected to the 15V terminal of the flyback switching power supply circuit. The second end of resistor R7 is connected to the first end of the thermistor TH1. The second end of the thermistor TH1 is connected to the first ends of resistors R11 and R61, and the non-inverting input terminal of comparator COMP3. The second end of resistor R11 is grounded. The inverting input terminal of comparator COMP3 is connected to a 2.5V power supply through resistor R69. The second end of resistor R61 is connected to the output terminal of comparator COMP3. The output terminal of comparator COMP3 is connected to the positive terminal of diode D15 in the sampling unit. This invention is configured such that the over-temperature protection circuit controls the operation of the PFC DC power supply circuit through the input over-voltage and under-voltage protection circuit. When an over-temperature occurs, the MOSFET Q11 is turned off, which de-energizes the VCC pin of the boost controller U4, thereby stopping the PFC DC power supply circuit from working and achieving the over-temperature protection function.

[0027] In an embodiment of this utility model, the output short-circuit protection circuit includes resistors R22, R70, R70A, R73, R74, and R75, diodes D13, D21, and D22, MOSFET Q14, transistor Q10, comparator U2B, and comparator COMP1. The inverting input of comparator U2B is connected to power supply VREF, and the non-inverting input of comparator U2B is connected to the OCP terminal of the DC output control circuit. The output of comparator U2B is connected to the first terminal of resistor R72 and the inverting input of comparator COMP1 through diode D22. The second terminal of resistor R72 is grounded, and the non-inverting input of comparator COMP1 is connected to the first terminal of resistor R72. The first terminal of resistor R70A is connected to the first terminal of resistor R70. The second terminal of resistor R70A is connected to a 2.5V power supply. The second terminal of resistor R70 is connected to the output terminal of comparator COMP4 through diode D21. The output terminal of comparator COMP4 is connected to the first terminal of resistor R73. The second terminal of resistor R73 is connected to the gate of MOSFET Q14. The source of MOSFET Q14 is grounded. The drain of MOSFET Q14 is connected to the first terminal of resistor R74 and the base of transistor Q10. The collector of transistor Q10 and the second terminal of resistor R74 are connected to the VCC pin of boost controller U4. The emitter of transistor Q10 is grounded through resistor R75, diode D13 and resistor R28. The working principle of the output short-circuit protection circuit is as follows: When the DC output control circuit of this invention experiences an output short circuit, the comparator U2B and comparator COMP4 of the input undervoltage protection unit control transistor Q10 to conduct, causing the voltage at the VCC pin of the boost controller U4 to be pulled low, thereby stopping the PFC DC power supply circuit from working and thus realizing the output short-circuit protection function; when the DC output control circuit of this invention resolves the output short circuit, the comparator U2B and comparator COMP4 of the input undervoltage protection unit control transistor Q10 to be turned off, causing the voltage at the VCC pin of the boost controller U4 to rise, thereby enabling the PFC DC power supply circuit to work and allowing the entire circuit to automatically recover.

[0028] In an embodiment of this utility model, the control terminal of the DC output control circuit is connected to the VCC pin of the boost controller U4. In this way, when the PFC DC power supply circuit is working, the DC output control circuit is also working and conducting; and when the PFC DC power supply circuit is not working, the DC output control circuit is turned off to reduce energy consumption.

[0029] In embodiments of this invention, the 2.5V power supply and the VREF power supply can be obtained from the flyback switching power supply circuit through a voltage divider circuit.

[0030] The above embodiments and figures are not intended to limit the product form and style of this utility model. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of this utility model.

Claims

1. A multi-protection AC / DC dual-output power supply, characterized in that: It includes an AC input circuit, an AC output control circuit, a PFC DC power supply circuit, a DC output control circuit, a flyback switching power supply circuit, an input overvoltage and undervoltage protection circuit, an overtemperature protection circuit, an output short circuit protection circuit, and a main control circuit. The AC input side of the AC output control circuit is connected to the AC output side of the AC input circuit; The AC input side of the PFC DC power supply circuit is connected to the AC output side of the AC input circuit, and the DC input side of the DC output control circuit and the DC input side of the flyback switching power supply circuit are connected to the DC output side of the PFC DC power supply circuit. The two input sides of the input overvoltage and undervoltage protection circuit are connected to the AC input side of the PFC DC power supply circuit and the DC output side of the flyback switching power supply circuit, respectively. The output side of the input overvoltage and undervoltage protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit. The input side of the output short-circuit protection circuit is connected to the DC output control circuit, and the output side of the output short-circuit protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit. The over-temperature protection circuit is connected to the VCC pin of the boost controller U4 of the PFC DC power supply circuit through the input over-voltage and under-voltage protection circuit; The main control circuit is connected to the PFC DC power supply circuit and controls whether the PFC DC power supply circuit works; the main control circuit is also connected to the AC output control circuit and controls the AC output control circuit to turn on and off.

2. The multi-protection AC / DC dual-output power supply as described in claim 1, characterized in that: The AC output control circuit includes a relay RL1 and an AC output port J0. The AC input terminal of the output circuit of relay RL1 is connected to the AC1 terminal of the AC input circuit. The AC output terminal of relay RL1 is connected to the L pin of AC output port J0. The two DC control terminals of relay RL1 are connected to the main control circuit. The N pin of AC output port J0 is connected to the AC2 terminal of the AC input circuit.

3. The multi-protection AC / DC dual-output power supply as described in claim 1, characterized in that: The input overvoltage and undervoltage protection circuit includes an input undervoltage protection unit and an input overvoltage protection unit; The input undervoltage protection unit includes diodes D3, D4, and D16, resistors R15, R29, R32, R34, R62, R65, R67, R83, and R84, MOSFET Q13, and comparator COMP1. The anodes of diodes D3 and D4 are connected to the AC1- and AC2- terminals of the PFC DC power supply circuit, respectively. The cathodes of diodes D3 and D4 are connected to the first terminal of resistor R29. The second terminal of resistor R29 is connected to the first terminals of resistors R15 and R34. The second terminal of resistor R34 and the first terminal of resistor R62 are connected via a... The sample unit is connected to the DC output side of the flyback switching power supply circuit. The second end of resistor R62 is grounded. The second end of resistor R15 is connected to the inverting input of comparator COMP1. The non-inverting input of comparator COMP1 is connected to the first end of resistor R65 and the first end of resistor R67. The second end of resistor R65 is connected to the 2.5V power supply. The second end of resistor R67 is connected to the output of comparator COMP1 through diode D16. The output of comparator COMP1 is connected to the first end of resistor R84. The second end of resistor R84 is connected to the first end of resistor R83 and the gate of MOSFET Q13. The drain of MOSFET Q13 is connected to the VCC pin of boost controller U4. The input overvoltage protection unit includes resistors R63, R64, R66, R81, R82, diode D17, MOSFET Q11, and comparator COMP2. The first terminal of resistor R63 is connected to the DC output side of the flyback switching power supply circuit through a sampling unit. The second terminal of resistor R63 and the first terminal of resistor R64 are connected to the non-inverting input terminal of comparator COMP2. The inverting input terminal of comparator COMP2 is connected to the 2.5V power supply through resistor R66. The second terminal of resistor R64 is connected to the output terminal of comparator COMP2 through diode D17. The output terminal of comparator COMP2 is connected to the first terminal of resistor R82. The second terminal of resistor R82 is connected to the first terminal of resistor R81 and the gate of MOSFET Q11. The source of MOSFET Q11 is connected to the 15V SELV terminal of the flyback switching power supply circuit. The drain of MOSFET Q11 is connected to the second terminal of resistor R83 and the source of MOSFET Q13.

4. The multi-protection AC / DC dual-output power supply as described in claim 3, characterized in that: The input overvoltage and undervoltage protection circuit also includes a main control switch unit. The source of MOSFET Q13 is connected to the drain of MOSFET Q11 through the main control switch unit. The main control switch unit includes resistors R17, R18, and R36, and MOSFET Q2. The drain of MOSFET Q2 is connected to the source of MOSFET Q13. The source of MOSFET Q2 is connected to the drain of MOSFET Q11 through resistor R18. The gate of MOSFET Q2 is connected to the first terminal of resistor R17 and the first terminal of resistor R36. The second terminal of resistor R17 is connected to the drain of MOSFET Q11. The second terminal of resistor R36 is connected to the main control circuit.

5. The multi-protection AC / DC dual-output power supply as described in claim 3, characterized in that: The sampling unit includes resistor R60, resistor R62 and diode D15. The first end of resistor R60 is connected to the 15V terminal of the flyback switching power supply circuit. The second end of resistor R60 is connected to the positive terminal of diode D15. The negative terminal of diode D15 and the first end of resistor R62 are connected to the second end of resistor R34, the first end of resistor R62 and the first end of resistor R63. The second end of resistor R62 is grounded.

6. The multi-protection AC / DC dual-output power supply as described in claim 5, characterized in that: The over-temperature protection circuit includes resistors R7, R11, R61, R69, a thermistor TH1, and a comparator COMP3. The first end of resistor R7 is connected to the 15V terminal of the flyback switching power supply circuit. The second end of resistor R7 is connected to the first end of the thermistor TH1. The second end of the thermistor TH1 is connected to the first ends of resistors R11 and R61, and the non-inverting input of comparator COMP3. The second end of resistor R11 is grounded. The inverting input of comparator COMP3 is connected to a 2.5V power supply through resistor R69. The second end of resistor R61 is connected to the output of comparator COMP3. The output of comparator COMP3 is connected to the positive terminal of diode D15 in the sampling unit.

7. The multi-protection AC / DC dual-output power supply as described in claim 1, characterized in that: The output short-circuit protection circuit includes resistors R22, R70, R70A, R73, R74, and R75, diodes D13, D21, and D22, MOSFET Q14, transistor Q10, comparator U2B, and comparator COMP1. The inverting input of comparator U2B is connected to power supply VREF, and the non-inverting input is connected to the OCP terminal of the DC output control circuit. The output of comparator U2B is connected to the first terminal of resistor R72 and the inverting input of comparator COMP4 via diode D22. The second terminal of resistor R72 is grounded, and the non-inverting input of comparator COMP4 is connected to resistor R... The first terminal of resistor R70 is connected to the first terminal of resistor R70. The second terminal of resistor R70A is connected to a 2.5V power supply. The second terminal of resistor R70 is connected to the output terminal of comparator COMP4 through diode D21. The output terminal of comparator COMP4 is connected to the first terminal of resistor R73. The second terminal of resistor R73 is connected to the gate of MOSFET Q14. The source of MOSFET Q14 is grounded. The drain of MOSFET Q14 is connected to the first terminal of resistor R74 and the base of transistor Q10. The collector of transistor Q10 and the second terminal of resistor R74 are connected to the VCC pin of boost controller U4. The emitter of transistor Q10 is grounded through resistor R75, diode D13 and resistor R28.

8. The multi-protection AC / DC dual-output power supply as described in claim 1, characterized in that: The control terminal of the DC output control circuit is connected to the VCC pin of the boost controller U4.

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