A power supply voltage regulation and short circuit protection control circuit

Abstract

This invention relates to the field of power electronics technology and discloses an output power supply voltage regulation and short-circuit protection control circuit. By connecting a voltage regulation output protection circuit unit at the V01 and V02 output terminals of the power unit circuit, the circuit unit includes a first voltage regulation control circuit, a second voltage regulation control circuit, and a short-circuit protection control circuit. This effectively solves the problems of voltage regulation control and short-circuit protection for the positive and negative outputs of a dual-output power supply, achieving linear voltage regulation control for both positive and negative outputs. By utilizing a voltage regulation control method where the negative output follows the positive output, short-circuit protection for both positive and negative outputs is achieved. This avoids the problem of excessively large differences between the short-circuit over-power point and the rated output power point of the positive and negative outputs.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, specifically to an output power supply voltage regulation and short-circuit protection control circuit. Background Technology

[0002] For multi-output power supplies (with a larger main output and smaller positive and negative outputs), the main output voltage is stabilized through isolation feedback control; the secondary output voltage is stabilized using linear regulation due to its smaller output power. When the main output is short-circuited, short-circuit protection can be implemented for the entire circuit by detecting the transformer primary current. Because the main output power is large, short-circuit protection control using transformer primary current detection can achieve short-circuit protection under relatively small overpower conditions. However, the positive and negative outputs have smaller output power and are controlled in an open-loop manner relative to the input, with relatively stable output voltage only when maintaining a relatively balanced load with the main output. When a short circuit occurs in either the positive or negative output, short-circuit protection can only be triggered by transformer primary current sampling under extremely high overpower conditions. This results in a significant difference between the short-circuit protection power point and the rated output power point for the positive and negative outputs, potentially leading to the risk of the load burning out under short-circuit faults.

[0003] (1) Common voltage regulation and protection methods for multi-output power supplies

[0004] Common methods for voltage regulation and protection of multi-channel power supplies include: Figure 1 As shown, the main output Vo uses closed-loop control for output voltage regulation, while the positive and negative outputs use linear regulators (LDOs) for voltage regulation. Output short-circuit protection generally includes two methods: 1. Short-circuit protection for the main output Vo and the positive and negative outputs Vo1 and Vo2 is uniformly achieved through primary-side Rs sampling control; 2. The main output Vo is protected through primary-side Rs sampling control, while the positive and negative outputs Vo1 and Vo2 are protected through the LDO's own overcurrent protection. Problems exist: It requires an expensive linear regulator (LDO), and if primary-side Rs sampling protection is used, there is a problem of excessive protection power for the positive and negative outputs.

[0005] (2) A multi-output short-circuit protection circuit and switching power supply, patent number CN 208174240U discloses a multi-output short-circuit protection circuit, specifically as follows: Figure 2As shown. When the auxiliary voltage output unit is working normally, because the auxiliary voltage is higher than the main voltage, diodes D1 or D2 are in the off state, and both the auxiliary and main voltage output units operate normally. When the auxiliary voltage output unit is short-circuited, diodes D1 or D2 conduct, and the main voltage output unit is also short-circuited. At this time, the short-circuit protection function of the main voltage output unit starts to work, causing the main body of the switching power supply to detect the output short circuit and give a control signal, thereby realizing short-circuit protection. Problems: This protection method is only applicable when the auxiliary output voltage is higher than the main output voltage; at the same time, since the main output power is much greater than the auxiliary output power, when the auxiliary circuit is short-circuited, the main circuit and the auxiliary circuit are short-circuited simultaneously through the diode in series. At this time, the short-circuit current of the main circuit will flow to ground through the auxiliary circuit. Excessive short-circuit current flowing through the auxiliary circuit branch will cause the auxiliary circuit to burn out.

[0006] (3) A multi-output short-circuit protection circuit, patent number CN 210985632U

[0007] A multi-output short-circuit protection circuit is disclosed, specifically as follows: Figure 3 As shown, the multi-output short-circuit protection circuit includes a power supply module, an input winding, multiple output windings, and multiple short-circuit detection circuits. The short-circuit detection circuits adjust their output short-circuit control signals based on the isolation power supply signals output by their respective output windings. The short-circuit protection circuit adjusts the power supply control signal output to the power supply module based on the short-circuit control signals from all the short-circuit detection circuits, thereby controlling the power supply state from the power supply module to the input windings and achieving short-circuit protection for each isolated power supply output branch. Problems: Each branch of this protection method requires a short-circuit detection circuit, which includes signal acquisition, fault judgment comparison, and signal isolation. For multi-output power supplies, multiple detection circuits are needed, resulting in a complex circuit structure and high cost. Summary of the Invention

[0008] To address the problems existing in the prior art, the present invention provides an output power supply voltage regulation and short-circuit protection control circuit.

[0009] This invention is achieved through the following technical solution:

[0010] A voltage regulation and short-circuit protection control circuit for output power includes a voltage regulation output protection circuit unit connected to the VO1 and VO2 output terminals of a power unit circuit. The voltage regulation output protection circuit unit includes a first voltage regulation control circuit, a second voltage regulation control circuit, and a short-circuit protection control circuit. One end of the first voltage regulation control circuit is connected to the VO1 output terminal, and the other end is connected to output ground. One end of the short-circuit protection control circuit is connected to the VO2 output terminal, and the other end is connected to output ground. One end of the second voltage regulation control circuit is connected to both output ground and the VO1 output terminal, and the other end is connected to the VO2 output terminal.

[0011] The first voltage regulation control circuit includes a power supply circuit, a first sampling circuit, and a first feedback control circuit connected in sequence; the second voltage regulation control circuit includes a second sampling circuit and a second feedback control circuit connected in sequence.

[0012] Preferably, the power unit circuit includes the secondary winding T1 of the switching power supply power transformer, Schottky diodes D1, D2, D3, and D4, power transistors Q5 and Q6, output filter capacitors Co1, Co2, Co3, and Co4, resistors RL1 and RL2;

[0013] The secondary winding T1 of the switching power supply power transformer includes winding terminals T1-7, T1-8, and T1-9, wherein winding terminals T1-7 to T1-8 are terminals of the same name, and winding terminals T1-8 to T1-9 are terminals of different names; the anode of the Schottky diode D1 is connected to winding terminal T1-7, and the cathode is connected to the output terminal VO1 via power transistor Q5; the cathode of the Schottky diode D2 is connected to winding terminal T1-7, and the anode is connected to the output terminal VO2 via power transistor Q6; the anode of the Schottky diode D4 is connected to winding terminal T1-9, and the cathode is connected to the output terminal VO1 via power transistor Q5; the Schottky diode... The cathode of transistor D3 is connected to winding terminal T1-9, and the anode is connected to the output terminal of VO2 via power transistor Q6; winding terminal T1-8 is connected to output ground; the output filter capacitors Co1 and Co2 are connected in series between power transistors Q5 and Q6; the first voltage regulation control circuit, output filter capacitor Co3, and resistor RL1 are located between the output terminal of VO1 and output ground; the short-circuit protection control circuit, output filter capacitor Co4, and resistor RL2 are located between the output terminal of VO2 and output ground; one end of the second voltage regulation control circuit is connected to output ground and the output terminal of VO1, and the other end is connected to the output terminal of VO2.

[0014] Preferably, the power supply circuit includes a transistor Q7, a Zener diode Z1, a resistor R4, and a capacitor C2. One end of the resistor R4 is connected to the output terminal of VO1, and the other end is connected to the cathode of the Zener diode Z1. The anode of the Zener diode Z1 is connected to the output ground. The cathode of the Zener diode Z1 is connected to the base of the transistor Q7. The collector of the transistor Q7 and the collector of the power transistor Q5 are connected to the cathode of the diode D1. The emitter of the transistor Q7 is connected to the output ground through the capacitor C2.

[0015] Furthermore, the emitter output power supply Vcc of transistor Q7 is used to provide power to the operational amplifier of the feedback control circuit.

[0016] Preferably, the first sampling circuit includes resistors R2 and R3. One end of resistor R2 is connected to the output terminal of VO1, and the other end, together with resistor R3, is connected to the inverting terminal of the operational amplifier of the first feedback control circuit; the other end of resistor R3 is connected to the output ground.

[0017] Furthermore, the first feedback control circuit includes an operational amplifier U1, a resistor R1, and a capacitor C1; the non-inverting input of the operational amplifier U1 is connected to a reference voltage Vref, and the inverting input is connected to resistors R2 and R3; resistor R1 and capacitor C1 are connected in series between the inverting input and the output of the operational amplifier, and the output of the operational amplifier is connected to the base of the power transistor Q5.

[0018] Preferably, the second sampling circuit includes resistors R5 and R6; resistors R5 and R6 are connected in series between the output terminals Vo1 and Vo2, and the common terminal of resistors R5 and R6 is connected to the inverting input of the operational amplifier of the second feedback control circuit.

[0019] Furthermore, resistors R5 and R6 have the same resistance value.

[0020] Furthermore, the second feedback control circuit includes an operational amplifier U2, a resistor R7, and a capacitor C3. The resistor R7 and the capacitor C3 are connected in series to the inverting input and the output of the operational amplifier U2 to form a buffer compensation circuit. The non-inverting input of the operational amplifier U2 is connected to the output ground. The output of the operational amplifier is connected to the base of the power transistor Q6.

[0021] Preferably, the short-circuit protection control circuit includes an operational amplifier U3, resistors R8 and R9. The non-inverting input of the operational amplifier U3 is connected to the output ground, the inverting input is connected to the output of Vo2 through resistor R8, and the inverting input is connected to the output of the operational amplifier U3 through resistor R9. The output of the operational amplifier U3 is connected to the power supply reference voltage Vref.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] This invention provides an output power supply voltage regulation and short-circuit protection control circuit. By connecting a voltage regulation output protection circuit unit at the VO1 and VO2 output terminals of the power unit circuit, the circuit includes a first voltage regulation control circuit, a second voltage regulation control circuit, and a short-circuit protection control circuit. This effectively solves the problems of voltage regulation control and short-circuit protection for the positive and negative outputs of a dual-output power supply, achieving linear voltage regulation control for both positive and negative outputs. By utilizing a voltage regulation control method where the negative output follows the positive output, short-circuit protection for both positive and negative outputs is achieved. This avoids the problem of excessively large differences between the short-circuit over-power point and the rated output power point for both positive and negative outputs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a common multi-output voltage regulation control and short-circuit protection circuit structure in the prior art;

[0025] Figure 2 This is a schematic diagram of a multi-output short-circuit protection circuit and a switching power supply structure in the prior art.

[0026] Figure 3 This is a schematic diagram of a multi-output short-circuit protection circuit in the prior art;

[0027] Figure 4 This is a schematic diagram of the three-output power supply voltage regulation control and short-circuit protection control circuit in this invention;

[0028] Figure 5 This is a schematic diagram of the push-pull power conversion topology with three outputs in an embodiment of the present invention.

[0029] In the diagram: 1-First voltage regulation control circuit; 2-Second voltage regulation control circuit; 3-Short circuit protection control circuit; 4-Power unit circuit. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] The present invention will now be described in further detail with reference to the accompanying drawings:

[0033] See Figure 4In one embodiment of the present invention, an output power supply voltage regulation and short-circuit protection control circuit is provided, including a voltage regulation output protection circuit unit connected to the VO1 output terminal and the VO2 output terminal of the power unit circuit 4. The voltage regulation output protection circuit unit comprises a first voltage regulation control circuit 1, a second voltage regulation control circuit 2, and a short-circuit protection control circuit 3; one end of the first voltage regulation control circuit 1 is connected to the VO1 output terminal, and the other end is connected to the output ground; one end of the short-circuit protection control circuit 3 is connected to the VO2 output terminal, and the other end is connected to the output ground; one end of the second voltage regulation control circuit 2 is connected to both the output ground and the VO1 output terminal, and the other end is connected to the VO2 output terminal.

[0034] Specifically, the power unit circuit 4 includes the secondary winding T1 of the switching power supply power transformer, Schottky diodes D1, D2, D3, and D4, power transistors Q5 and Q6, output filter capacitors Co1, Co2, Co3, and Co4, resistors RL1 and RL2;

[0035] The secondary winding T1 of the switching power supply power transformer includes winding terminals T1-7, T1-8, and T1-9, wherein winding terminals T1-7 to T1-8 are terminals of the same name, and winding terminals T1-8 to T1-9 are terminals of different names; the anode of the Schottky diode D1 is connected to winding terminal T1-7, and the cathode is connected to the output terminal VO1 via power transistor Q5; the cathode of the Schottky diode D2 is connected to winding terminal T1-7, and the anode is connected to the output terminal VO2 via power transistor Q6; the anode of the Schottky diode D4 is connected to winding terminal T1-9, and the cathode is connected to the output terminal VO1 via power transistor Q5; the Schottky diode... The cathode of D3 is connected to winding terminal T1-9, and the anode is connected to the output terminal of VO2 via power transistor Q6; winding terminal T1-8 is connected to output ground; the output filter capacitors Co1 and Co2 are connected in series between power transistors Q5 and Q6; the first voltage regulation control circuit 1, the output filter capacitor Co3, and the resistor RL1 are located between the output terminal of VO1 and output ground; the short circuit protection control circuit 3, the output filter capacitor Co4, and the resistor RL2 are located between the output terminal of VO2 and output ground; one end of the second voltage regulation control circuit 2 is connected to output ground and the output terminal of VO1, and the other end is connected to the output terminal of VO2.

[0036] Windings T1-7 to T1-8 and T1-8 to T1-9 are the secondary windings of the power transformer in the switching power supply, with T1-7 and T1-8 being the same-name terminals. Schottky diodes D1 to D4 form a rectifier bridge. When the same-name terminals (T1-7 and T1-8) are at high voltage, diodes D1 and D3 conduct, and the energy from the transformer windings is output from T1-7, flowing through D1, Q5, the loads RL1, RL2, Q6, and D3 back to T1-9. When the opposite-name terminals are at high voltage, D4 ​​and D2 conduct, and the energy from the transformer windings is output from T1-9, flowing through Q5, RL1, RL2, Q6, and D2 back to T1-7. Capacitors Co1, Co2, Co3, and Co4 are output filter capacitors.

[0037] The first voltage regulation control circuit 1 includes a power supply circuit, a first sampling circuit, and a first feedback control circuit connected in sequence.

[0038] Specifically, the power supply circuit includes transistor Q7, Zener diode Z1, resistor R4, and capacitor C2. One end of resistor R4 is connected to the output terminal of V01, and the other end is connected to the cathode of Zener diode Z1. The anode of Zener diode Z1 is connected to the output ground. The cathode of Zener diode Z1 is connected to the base of transistor Q7. The collector of transistor Q7 and the collector of power transistor Q5 are connected to the cathode of diode D1. The emitter of transistor Q7 is connected to the output ground through capacitor C2. The emitter output power supply Vcc of transistor Q7 is used to provide power to the operational amplifier of the feedback control circuit, and the supply voltage Vcc2 = Vz1 - 0.7V.

[0039] Specifically, the first sampling circuit includes resistors R2 and R3. One end of resistor R2 is connected to the output terminal of VO1, and the other end, together with resistor R3, is connected to the inverting terminal of the operational amplifier of the first feedback control circuit; the other end of resistor R3 is connected to the output ground.

[0040] Specifically, the first feedback control circuit includes an operational amplifier U1, a resistor R1, and a capacitor C1; the non-inverting input of the operational amplifier U1 is connected to a reference voltage Vref, and the inverting input is connected to resistors R2 and R3; resistor R1 and capacitor C1 are connected in series between the inverting input and the output of the operational amplifier, and the output of the operational amplifier is connected to the base of the power transistor Q5.

[0041] The voltage regulation working principle of the first voltage regulation control circuit 1 in this invention is as follows:

[0042] The output voltage Vo1, after being current-limited and regulated by resistor R4 and Zener diode Z1, provides a bias voltage and base current to the base of transistor Q7. This bias voltage and base current are then amplified by transistor Q7 to form Vcc2, which powers the internal operational amplifier. The positive output voltage Vo1 signal to ground is sampled by resistors R2 and R3 and input to the inverting input of operational amplifier U1. When the output voltage Vo1 increases, the sampled voltage increases accordingly. When this signal voltage is greater than the reference voltage Vref, the output voltage of operational amplifier U1 decreases, reducing the base current of transistor Q5, increasing the voltage difference between the collector and emitter of Q5, and thus decreasing the output voltage Vo1. Similarly, when the output voltage Vo1 decreases, the sampled voltage decreases accordingly. When this signal voltage is less than the reference voltage Vref, the output voltage of operational amplifier U1 increases, increasing the base current of transistor Q5, decreasing the voltage difference between the collector and emitter of Q5, and thus increasing the output voltage Vo1. Resistor R1 and capacitor C1 form a buffer compensation circuit to prevent the operational amplifier from responding too quickly and causing oscillation when Vo1 fluctuates rapidly. The negative feedback voltage regulation process is as follows: Vo1 increases → Vfb1 increases → Vo(U1) decreases → Vce(Q5) increases → Vo1 decreases.

[0043] The second voltage regulation control circuit includes a second sampling circuit and a second feedback control circuit connected in sequence.

[0044] Specifically, the second sampling circuit includes resistors R5 and R6; resistors R5 and R6 are connected in series between the output terminals Vo1 and Vo2, and the common terminal of resistors R5 and R6 is connected to the inverting input of the operational amplifier of the second feedback control circuit. Resistors R5 and R6 have the same resistance value.

[0045] Specifically, the second feedback control circuit includes an operational amplifier U2, a resistor R7, and a capacitor C3. The resistor R7 and the capacitor C3 are connected in series between the inverting input and the output of the operational amplifier U2 to form a buffer compensation circuit. The non-inverting input of the operational amplifier U2 is connected to the output ground. The output of the operational amplifier is connected to the base of the power transistor Q6.

[0046] The voltage regulation working principle of the first voltage regulation control circuit 2 in this invention is as follows:

[0047] When the output voltage Vo2 increases negatively, the sampling voltage Vfb at the inverting input of the operational amplifier becomes negative. This voltage is lower than the ground level at the non-inverting input, causing the output voltage of operational amplifier U2 to rise. The base current of transistor Q6 decreases, increasing the voltage difference between the emitter and collector of Q6, thus compensating for the negative change in Vo2. Similarly, when the output voltage Vo2 decreases negatively, the sampling voltage Vfb rises immediately. This signal voltage is greater than the non-inverting voltage (ground level) of operational amplifier U2, causing the output voltage of operational amplifier U2 to decrease. The base current of transistor Q6 increases, decreasing the voltage difference between the emitter and collector of Q6, thus increasing the negative output voltage Vo2. Resistor R7 and capacitor C3 form a buffer compensation circuit to prevent the operational amplifier from responding too quickly and causing oscillation when Vo2 fluctuates rapidly. The negative feedback voltage regulation process is: Vo2 increases negatively → Vfb2 decreases → Vo(U2) increases → Vec(Q6) increases → Vo2 decreases negatively. Since the sampling signal Vfb2 comes from Vo1 and Vo2, the regulated voltage of Vo2 follows the change of Vo1.

[0048] Specifically, the short-circuit protection control circuit 3 includes an operational amplifier U3, resistors R8 and R9. The non-inverting input of the operational amplifier U3 is connected to the output ground, the inverting input is connected to the output of Vo2 through resistor R8, and the inverting input is connected to the output of the operational amplifier U3 through resistor R9. The output of the operational amplifier U3 is connected to the power supply reference voltage Vref.

[0049] The specific working principle of the short-circuit protection control circuit 3 in this invention is as follows:

[0050] When Vo2 is short-circuited, the voltage at Vo2 decreases negatively, and the output voltage of operational amplifier U3 decreases proportionally, thus pulling down the switching power supply reference voltage Vref, and further pulling down the voltages Vo1 and Vo2. If Vo1 is short-circuited, because Vo2 follows the change in Vo1, Vo2 will also decrease, triggering short-circuit protection.

[0051]

[0052] Example

[0053] Specific applications of the present invention are as follows: Figure 5 As shown, a push-pull power converter topology with three outputs is used as an example. The main output Vo is controlled by a control loop (error signal amplification, signal isolation, PWM modulation) to adjust the duty cycles of VDMOS transistors Q1 and Q2, with Q1 and Q2 conducting alternately. Vref is the reference voltage for the error signal in the control loop. Vo1 and Vo2 are the positive and negative outputs, respectively, and their output voltages are stabilized by voltage regulator circuits 1 and 2. Protection circuit 3 provides short-circuit protection for both positive and negative outputs. Short-circuit protection for the main output (Vo) is achieved through sampling control of the primary-side resistor Rs.

[0054] This invention relates to an output power supply voltage regulation and short-circuit protection control circuit, particularly for a three-output power supply, including a main output and positive and negative outputs. The main output has a higher power (greater than 2 / 3 of the total power), while the positive and negative outputs have lower power (less than 1 / 3 of the total power). The main output uses a closed-loop control system to stabilize its output voltage, while the positive and negative outputs employ linear voltage regulation control under relatively balanced load conditions. The invention also includes a linear voltage regulation circuit and a short-circuit protection circuit for the lower-power positive and negative outputs.

[0055] In summary, this invention provides an output power supply voltage regulation and short-circuit protection control circuit. By connecting a voltage regulation output protection circuit unit to the V01 and V02 output terminals of the power unit circuit 4, wherein the voltage regulation output protection circuit unit includes a first voltage regulation control circuit, a second voltage regulation control circuit, and a short-circuit protection control circuit, it effectively solves the voltage regulation control and short-circuit protection of the positive and negative outputs of the three-way output power supply. It achieves linear voltage regulation control of the positive and negative outputs, and utilizes a voltage regulation control method where the negative circuit follows the positive circuit to achieve short-circuit protection for both positive and negative outputs. This avoids the problem of excessively large differences between the short-circuit over-power point and the rated output power point of the positive and negative outputs.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An output power supply voltage regulation and short-circuit protection control circuit, characterized in that, The circuit includes a voltage regulation output protection circuit unit connected to the output terminals of the power unit circuit (4) at V01 and V02. The voltage regulation output protection circuit unit includes a first voltage regulation control circuit (1), a second voltage regulation control circuit (2), and a short-circuit protection control circuit (3). One end of the first voltage regulation control circuit (1) is connected to the output terminal of V01, and the other end is connected to the output ground. One end of the short-circuit protection control circuit (3) is connected to the output terminal of V02, and the other end is connected to the output ground. The first end of the second voltage regulation control circuit (2) is connected to the output terminal of V01, the second end is connected to the output ground, and the third end is connected to the output terminal of V02. The first voltage regulation control circuit (1) includes a power supply circuit, a first sampling circuit and a first feedback control circuit connected in sequence; the second voltage regulation control circuit includes a second sampling circuit and a second feedback control circuit connected in sequence. The power unit circuit (4) includes the secondary winding T1 of the switching power supply power transformer, Schottky diodes D1, D2, D3, and D4, power transistors Q5 and Q6, output filter capacitors Co1, Co2, Co3, and Co4, resistors RL1 and RL2. The secondary winding T1 of the switching power supply power transformer includes winding terminals T1-7, T1-8, and T1-9 connected sequentially from top to bottom, wherein winding terminal T1-7 is the same-name terminal and winding terminal T1-9 is the opposite-name terminal; the anode of the Schottky diode D1 is connected to winding terminal T1-7, and the cathode is connected to the output terminal VO1 via power transistor Q5; the cathode of the Schottky diode D2 is connected to winding terminal T1-7, and the anode is connected to the output terminal VO2 via power transistor Q6; the anode of the Schottky diode D4 is connected to winding terminal T1-9, and the cathode is connected to the output terminal VO2 via power transistor Q5. V01 output terminal; the cathode of the Schottky diode D3 is connected to the winding terminal T1-9, and the anode is connected to the V02 output terminal via the power transistor Q6; the winding terminal T1-8 is connected to the output ground; the output filter capacitors Co1 and Co2 are connected in series between the power transistors Q5 and Q6; the first voltage regulation control circuit (1), the output filter capacitor Co3 and the resistor RL1 are located between the V01 output terminal and the output ground; the short circuit protection control circuit (3), the output filter capacitor Co4 and the resistor RL2 are located between the V02 output terminal and the output ground. The second sampling circuit includes resistors R5 and R6; resistors R5 and R6 are connected in series between the output terminals Vo1 and Vo2, and the common terminal of resistors R5 and R6 is connected to the inverting input of the operational amplifier of the second feedback control circuit.

2. The output power supply voltage regulation and short-circuit protection control circuit according to claim 1, characterized in that, The power supply circuit includes a transistor Q7, a Zener diode Z1, a resistor R4, and a capacitor C2. One end of the resistor R4 is connected to the output terminal of VO1, and the other end is connected to the cathode of the Zener diode Z1. The anode of the Zener diode Z1 is connected to the output ground. The cathode of the Zener diode Z1 is connected to the base of the transistor Q7. The collector of the transistor Q7 and the collector of the power transistor Q5 are connected to the cathode of the diode D1. The emitter of the transistor Q7 is connected to the output ground through the capacitor C2.

3. The output power supply voltage regulation and short-circuit protection control circuit according to claim 2, characterized in that, The emitter output power supply Vcc of the transistor Q7 is used to provide power to the operational amplifier of the feedback control circuit.

4. The output power supply voltage regulation and short-circuit protection control circuit according to claim 1, characterized in that, The first sampling circuit includes resistors R2 and R3. One end of resistor R2 is connected to the output terminal of VO1, and the other end, together with resistor R3, is connected to the inverting terminal of the operational amplifier of the first feedback control circuit. The other end of resistor R3 is connected to the output ground.

5. The output power supply voltage regulation and short-circuit protection control circuit according to claim 4, characterized in that, The first feedback control circuit includes an operational amplifier U1, a resistor R1, and a capacitor C1; the non-inverting input of the operational amplifier U1 is connected to a reference voltage Vref, and the inverting input is connected to resistors R2 and R3; resistor R1 and capacitor C1 are connected in series between the inverting input and the output of the operational amplifier, and the output of the operational amplifier is connected to the base of the power transistor Q5.

6. The output power supply voltage regulation and short-circuit protection control circuit according to claim 1, characterized in that, The resistors R5 and R6 have the same resistance value.

7. The output power supply voltage regulation and short-circuit protection control circuit according to claim 1, characterized in that, The second feedback control circuit includes an operational amplifier U2, a resistor R7, and a capacitor C3. The resistor R7 and the capacitor C3 are connected in series. The non-series connection point of the resistor R7 is connected to the output terminal of the operational amplifier U2, and the non-series connection point of the capacitor C3 is connected to the inverting input of the operational amplifier U2, forming a buffer compensation circuit. The non-inverting input of the operational amplifier U2 is connected to the output ground. The output terminal of the operational amplifier U2 is connected to the base of the power transistor Q6.

8. The output power supply voltage regulation and short-circuit protection control circuit according to claim 1, characterized in that, The short-circuit protection control circuit (3) includes an operational amplifier U3, a resistor R8 and a resistor R9. The non-inverting input of the operational amplifier U3 is connected to the output ground, the inverting input is connected to the output of Vo2 through the resistor R8, and the inverting input is connected to the output of the operational amplifier U3 through the resistor R9. The output of the operational amplifier U3 is connected to the power supply reference voltage Vref.

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