A high-voltage input reduced power consumption auxiliary source power supply circuit

Abstract

The utility model belongs to the technical field of auxiliary power supply, disclose a kind of auxiliary source power supply circuit of high voltage input reduces power consumption, port BUS+The positive end of diode D1 is connected, the negative end of D1 is connected with the one end of capacitor C1, the one end of resistance R8, the one end of resistance R11, the one end of resistance R14 and the pin 1 of transformer T1, the other end of C1 is connected with port BUS-, the other end of resistance R8 is connected with the drain of MOS tube Q1 through resistance R9 and resistance R10, the source of Q1 is connected with the positive end of D2, the negative end of D2 is connected with the negative end of D3 and the pin 1 of control chip U6, the positive end of D3 is connected with the one end of R3, the one end of R5, the one end of C7 and the negative end of D4.The utility model has the beneficial effects that: the loss brought by high voltage power supply can be reduced, the efficiency of auxiliary source is improved, and the circuit is simple and easy to understand, safe and reliable, with low cost, high efficiency and easy to realize, etc.

Description

Technical Field

[0001] This utility model relates to the field of auxiliary power supply technology, and in particular to an auxiliary power supply circuit that reduces power consumption by high voltage input. Background Technology

[0002] With the continuous development of power electronics and new energy technologies, switching power supplies are becoming increasingly diversified. Switching power supplies, with their advantages of low loss, high efficiency, small size, and low noise, have almost swept the electronics industry. As an indispensable part of switching power supplies, the auxiliary power supply unit provides power to the control circuit, drive circuit, and monitoring circuit of the main circuit of the switching power supply. It has the advantages of versatility, stability, and high efficiency. The auxiliary power supply is also crucial to the design of the entire switching power supply, significantly impacting its size, efficiency, stability, reliability, and cost. With the diversification of switching power supplies, high-voltage auxiliary power supplies have also emerged. However, high-voltage input startup also introduces high-voltage losses due to high-voltage starting resistors. A low-power auxiliary power supply is extremely important for the overall efficiency of the device.

[0003] Therefore, it is necessary to provide an auxiliary power supply circuit that reduces power consumption by high voltage input. This circuit can reduce the losses caused by high voltage power supply, improve the efficiency of the auxiliary power source, and is simple, easy to understand, safe, reliable, and has the advantages of low cost, high efficiency, and easy implementation. Utility Model Content

[0004] This utility model discloses an auxiliary power supply circuit for reducing power consumption by high voltage input, which can effectively solve the technical problems involved in the background art.

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

[0006] A high-voltage input auxiliary power supply circuit for reducing power consumption includes a port BUS+, a port BUS-, a control chip U6, and an optocoupler PC1.

[0007] The port BUS+ is connected to the positive terminal of diode D1. The negative terminal of diode D1 is connected to one end of capacitor C1, one end of resistor R8, one end of resistor R11, one end of resistor R14, and pin 1 of transformer T1. The other end of capacitor C1 is connected to port BUS-. The other end of resistor R8 is connected to the drain of MOSFET Q1 via resistors R9 and R10. The source of MOSFET Q1 is connected to the positive terminal of diode D2. The negative terminal of diode D2 is connected to the negative terminal of diode D3 and pin 1 of control chip U6. The positive terminal of diode D3 is connected to one end of resistor R3, one end of resistor R5, one end of capacitor C7, and diode D14. The negative terminal of diode D4 is connected to port OVP and one end of resistor R24. The other end of resistor R24 ​​is connected to pin 6 of transformer T1. The other end of resistor R3 is connected to the anode of optocoupler PC1 and one end of resistor R2. The cathode of optocoupler PC1 is connected to the other end of resistor R2 and one end of resistor R4. The other end of resistor R4 is connected to pin 3 of chip U1. Pin 1 of chip U1 is connected to the other end of resistor R5 and one end of resistor R6. Pin 2 of chip U1 is connected to port BUS-, the other end of resistor R6, the other end of capacitor C7, and pin 5 of transformer T1.

[0008] The other end of resistor R11 is connected to one end of resistor R12, the other end of resistor R12 is connected to one end of resistor R13, the other end of resistor R13 is connected to the cathode of Zener diode Z1, the anode of Zener diode Z1 is connected to the cathode of Zener diode Z2, the anode of Zener diode Z2 is connected to the cathode of Zener diode Z3, the anode of Zener diode Z3 is connected to the cathode of Zener diode Z4, the gate of MOSFET Q1 and one end of resistor R1, the other end of resistor R1 is connected to the collector of optocoupler PC1, and the anode of Zener diode Z4 is connected to the emitter of optocoupler PC1 and port BUS-.

[0009] The other end of resistor R14 is connected to pin 5 of control chip U6 via resistors R15, R16, R17, and R18. Port OVP is connected to one end of resistor R23. The other end of resistor R23 is connected to one end of resistor R22, one end of capacitor C3, and pin 8 of control chip U6. Pin 6 of control chip U6 is connected to one end of resistor R20. Pin 5 of control chip U6 is connected to one end of capacitor C4, one end of resistor R19, and the cathode of Zener diode Z5. The other end of resistor R22 is connected to the other end of capacitor C3, the other end of resistor R20, the anode of Zener diode Z5, the other end of resistor R19, the other end of capacitor C4, and port BUS-.

[0010] Pin 4 of the control chip U6 is connected to one end of capacitor C5 and one end of resistor R25. The other end of resistor R25 is connected to the collector of transistor Q3, one end of resistor R27, the source of MOSFET Q2, and one end of resistor R28. The other end of capacitor C5 is connected to pin 2 of the control chip U6, one end of capacitor C6, pin 1 of diode D5, the other end of resistor R28, and port BUS-. The other end of capacitor C6 is connected to pin 2 of diode D5 and pin 1 of the control chip U6. Pin 3 of the control chip U6 is connected to pin 3 of diode D5, one end of resistor R29, and the base of transistor Q3. The emitter of transistor Q3 is connected to one end of resistor R30. The other end of resistor R29 is connected to the other end of resistor R30, the other end of resistor R27, and the gate of MOSFET Q2. The drain of MOSFET Q2 is connected to pin 3 of transformer T1.

[0011] Pin 11 of the transformer T1 is connected to the positive terminal of diode D6, the negative terminal of diode D6 is connected to one end of capacitor C8 and port VOUT, and pin 9 of the transformer T1 is connected to the other end of capacitor C8 and port BAT-.

[0012] This utility model belongs to the field of high-voltage auxiliary power supply circuit technology, and discloses a circuit for reducing the power consumption of high-voltage auxiliary power supply. It includes an auxiliary power supply control unit, an auxiliary power supply VCC start-up power supply unit, and a VCC power supply winding output voltage detection and control unit. The auxiliary power supply VCC start-up power supply unit includes a diode D1. The cathode of diode D1 is connected to one end of capacitor C1 and to one end of resistor R8 and one end of resistor R11. The other end of capacitor C1 is connected to BUS-. The other end of resistor R8 is connected to R9. The other end of resistor R9 is connected to resistor R10. The other end of resistor R10 is connected to the drain of MOSFET Q1. The source of MOSFET Q1 is connected to one end of diode D2. The other end of diode D2 is connected to pin 1 of auxiliary power supply control chip U6. This circuit reduces the power consumption of high-voltage input power supply and provides low-voltage power supply through an independent winding after startup, effectively reducing the power consumption of the high-voltage auxiliary power supply and improving the efficiency of the auxiliary power supply. The circuit is simple and easy to understand, safe and reliable, and also has advantages such as low cost, real-time high efficiency, and ease of implementation.

[0013] As a preferred improvement of this utility model, the control chip U6 is IC-OB2276ACPA-T-SOP8.

[0014] As a preferred improvement of this utility model, the optocoupler PC1 is IC-EL1019-SMD4.

[0015] As a preferred improvement of this utility model: pin 7 of the control chip U6 is connected to port U6_FB and one end of capacitor C2, the other end of capacitor C2 is connected to the other end of capacitor C3, and port U6_FB is connected to the feedback terminal of port VOUT.

[0016] As a preferred improvement of this utility model: the chip U1 is IC-AZ431-SOT23.

[0017] As a preferred improvement of this utility model, the diode D5 is BAV99.

[0018] As a preferred improvement of this utility model: pins 9 and 11 of the transformer T1 share a common coil, pins 5 and 6 of the transformer T1 share a common coil, and pins 1 and 3 of the transformer T1 share a common coil.

[0019] The beneficial effects of this utility model are as follows:

[0020] When the high-voltage input voltage is divided to supply the auxiliary power source for starting, the auxiliary power source control chip sends a drive to control the switching transistor, thereby enabling the flyback circuit to work. The low-voltage winding then outputs power to the auxiliary power source control chip. As soon as the low-voltage winding has an output, it disconnects the high-voltage input power supply circuit, thereby reducing the losses caused by the high-voltage starting resistor. Using the AZ431, the voltage points for turning on and off the high-voltage input switching transistor can be precisely controlled, greatly improving the efficiency of the high-voltage auxiliary power source. Moreover, the circuit is simple and easy to understand, safe and reliable, low in cost, real-time and efficient, easy to implement, and easy to promote. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0022] Figure 1 This is a schematic diagram of an auxiliary power supply circuit for reducing power consumption by high voltage input according to this utility model;

[0023] Figure 2 for Figure 1 enlarge Figure 1 ;

[0024] Figure 3 for Figure 1 enlarge Figure 2 . Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0030] Please see Figures 1-3As shown, this utility model provides an auxiliary power supply circuit for reducing power consumption with high-voltage input, including a start-up power supply unit, a low-voltage winding power supply unit, and an auxiliary power supply control unit. The start-up power supply unit includes a port BUS+, which is connected to the anode of diode D1. The cathode of diode D1 is connected to one end of capacitor C1 and to one end of resistor R8, one end of resistor R14, and one end of resistor R11. The other end of capacitor C1 is connected to port BUS-. The other end of resistor R8 is connected to R9. The other end of resistor R9 is connected to resistor R10. The other end of resistor R10 is connected to the drain of MOSFET Q1. The source of MOSFET Q1 is connected to one end of diode D2. The other end of diode D2 is connected to pin 1 of auxiliary power supply control chip U6. The other end of resistor R14 is connected to one end of resistor R15, the other end of resistor R15 is connected to one end of resistor R16, the other end of resistor R16 is connected to one end of resistor R17, the other end of resistor R17 is connected to one end of resistor R18, resistor R18 is connected to one end of resistor R19, the cathode of Zener diode Z5, one end of capacitor C4, and pin 5 of auxiliary source control chip U6, and resistor R19, the anode of Zener diode Z5, and the other end of capacitor C4 are connected to port BUS-.

[0031] This startup power supply unit consists of a voltage divider circuit unit, a voltage regulator circuit unit, a clamping protection unit, and a MOS-FET unit. It provides startup voltage to the auxiliary power control unit. The control chip U6 of this auxiliary power control unit is IC-OB2276ACPA-T-SOP8, and the startup voltage is 21.5V. The startup voltage is provided by adjusting the resistance value of the voltage divider circuit. This circuit is simple to implement and easy to control.

[0032] The other end of resistor R11 is connected to one end of resistor R12, the other end of resistor R12 is connected to one end of resistor R13, the other end of resistor R13 is connected to the cathode of Zener diode Z1, the anode of Zener diode Z1 is connected to the cathode of Zener diode Z2, the anode of Zener diode Z2 is connected to the cathode of Zener diode Z3, the anode of Zener diode Z3 is connected to the cathode of Zener diode Z4 and the gate of MOSFET Q1, the anode of Zener diode Z4 is connected to pin 3 of isolation optocoupler PC1 and to port BUS-; pin 4 of isolation optocoupler PC1 is connected to one end of resistor R1, the other end of resistor R1 is connected to the gate of MOSFET Q1; pin 1 of auxiliary source control chip U6 is connected to the positive terminal of capacitor C6, and the negative terminal of capacitor C6 is connected to port BUS-. The isolation optocoupler PC1 is model IC-EL1019-SMD4.

[0033] The low-voltage winding power supply unit includes a transformer T1. Pin 6 of the transformer T1 is connected to one end of resistor R24. The other end of resistor R24 ​​is connected to the anode of diode D4. The cathode of diode D4 is connected to the positive terminal of capacitor C7, one end of resistor R5, one end of resistor R3, and the anode of diode D3. The cathode of diode D3 is connected to pin 1 of auxiliary source control chip U6. The negative terminal of capacitor C3 is connected to pin 5 of the transformer T1 and to port BUS-. The other end of resistor R3 is connected to pin 1 of isolation optocoupler PC1 and one end of resistor R2. Pin 2 of the isolation optocoupler is connected to the other end of resistor R2 and one end of resistor R4. The other end of resistor R4 is connected to pin 3 of chip U1. Pin 1 of chip U1 is connected to the other end of resistor R5 and one end of resistor R6. Pin 2 of chip U1 and the other end of resistor R6 are connected to port BUS-.

[0034] This low-voltage winding power supply unit comprises a voltage divider circuit unit, a voltage regulator circuit unit, and a rectifier unit. It forms a closed-loop control system with the start-up power supply unit and the auxiliary power supply control unit. The start-up power supply unit provides the start-up voltage for the auxiliary power supply control unit through resistor voltage division. Simultaneously, another voltage divider and regulator circuit turns on MOSFET Q1 to provide the start-up power supply voltage to the auxiliary power supply control unit. Once the auxiliary power supply control unit has voltage, it starts working and sends a drive to control the switching of MOSFET Q2, causing the transformer to start working. This causes the low-voltage winding power supply unit to also work, generating an induced electromotive force and rectifying it. The low-voltage winding power supply then provides VCC power to the auxiliary power supply control unit. To reduce losses caused by the high-voltage start-up resistor, the low-voltage winding power supply unit disconnects the high-voltage power supply from the start of operation, disconnecting MOSFET Q1. The auxiliary power supply control unit is then powered by the low-voltage supply, eliminating the need for a high-voltage power supply, significantly reducing losses in the auxiliary power supply and improving its efficiency. This circuit is simple, easy to control, and easy to implement. It improves the efficiency of the auxiliary power supply, reduces losses, and has a wide voltage input range, allowing for cost-effective improvement of the efficiency of the high-voltage auxiliary power supply.

[0035] Pin 11 of transformer T1 is connected to the anode of diode D6. The cathode of diode D6 is connected to the positive terminal of capacitor C8 and the main winding output port VOUT. Pin 9 of transformer T1 and the negative terminal of capacitor C8 are connected to port BAT-. The auxiliary source control unit includes auxiliary source control chip U6. Pins of auxiliary source control chip U6 are connected to the cathodes of diodes D2 and D3, the positive terminal of capacitor C6, and pin 2 of diode D5. The negative terminal of capacitor C6 is connected to port BUS-. Pin 2 of auxiliary source control chip U6 is connected to port BUS-. Pin 3 of auxiliary source control chip U6 is connected to the base of transistor Q3, one end of resistor R29, and pin 3 of diode D5. The emitter of transistor Q3 is connected to one end of resistor R30. The other end of resistor R30 is connected to one end of resistor R27, the other end of resistor R29, and the gate of MOSFET Q2. The source of MOSFET is connected to pin 3 of transformer T1. Pin 1 of transformer T1 is connected to the cathode of diode D2.

[0036] Pin 4 of the auxiliary power source control chip U6 is connected to the positive terminal of capacitor C5 and one end of resistor R25. The negative terminal of capacitor C5 is connected to port BUS-. The other end of resistor R25 is connected to the collector of transistor Q3, the other end of resistor R27, the drain of MOSFET Q2, and one end of resistor R28. The other end of resistor R28 is connected to port BUS-. Pin 1 of diode D5 is connected to port BUS-. The auxiliary power source control chip U6 is IC-OB2276ACPA-T-SOP8, and the switching diode D5 is BAV99.

[0037] Pin 5 of the auxiliary source control chip U6 is connected to one end of resistor R18, the cathode of the Zener diode Z5, one end of resistor R19, and one end of capacitor C4; pin 6 of the auxiliary source control chip U6 is connected to one end of resistor R20, and the other end of resistor R20 is connected to port BUS-; pin 7 of the auxiliary source control chip U6 is connected to one end of capacitor C2 and port U6_FB of the feedback circuit; pin 8 of the auxiliary source control chip U6 is connected to the positive terminal of capacitor C3, one end of resistor R22, and one end of resistor R23, the negative terminal of capacitor C3 and the other end of resistor R22 are connected to port BUS-, and the other end of resistor R23 is connected to the anode of diode D4 and the midpoint of resistor R24. The chip U1 is model IC-AZ431-SOT23.

[0038] Specifically, Figure 1The system includes an auxiliary power supply flyback circuit, a high-voltage start-up power supply unit, a low-voltage winding power supply unit, and an auxiliary power supply control unit. The high-voltage start-up power supply unit is connected to the auxiliary power supply control unit. The high-voltage input is controlled by a resistor divider and a Zener diode to regulate the voltage drop, thereby controlling the gate drive of the switching transistor and controlling its conduction. This provides the start-up voltage to the auxiliary power supply control unit after the start-up resistor divider. Once voltage is available, the control chip of the auxiliary power supply control unit starts working. Pin 3 of the auxiliary power supply control chip sends a drive, and the flyback circuit starts working. The induced electromotive force of the transformer T1-A winding is rectified by a diode, and the output voltage powers the auxiliary power supply control chip. Because the auxiliary power supply control chip has a high start-up voltage, while the normal operating voltage only needs to be 15V, the transformer T1-A winding is controlled by a voltage divider. The turns ratio is adjusted to output 15V. When the transformer TI-A winding has an output voltage, the optocoupler feedback circuit starts working. When the voltage drop of the voltage divider resistor reaches the turn-on voltage of the AZ431 chip, the AZ431 chip turns on, and the isolation optocoupler also turns on. After the other side of the isolation optocoupler turns on, it pulls down the gate voltage of the switching transistor, turns off the switching transistor, and disconnects the high-voltage input power supply. This greatly reduces the loss caused by the high-voltage input resistance after the auxiliary source is working normally. The transformer T1-A winding further reduces the loss by reducing the power supply voltage of the auxiliary source control chip. At the same time, the AZ431 chip can precisely control the voltage of the low-voltage power supply winding to turn off and on the switching transistor of the start-up power supply unit. The switching time of the high-voltage input start-up unit switching transistor can be adjusted during the voltage rise of the low-voltage power supply winding, which is adjustable.

[0039] The auxiliary power source control chip's pin 3, the drive pin, is connected to a transistor for rapid turn-off, further improving the efficiency of the auxiliary power source circuit module. A BAV99 diode is also added for clamping protection, preventing damage to the auxiliary power source control chip due to excessive drive voltage. Pin 4 of the auxiliary power source control chip uses a resistor to sample the flyback main circuit current for overcurrent protection. Pin 5, the undervoltage protection pin, detects the input voltage through a voltage divider resistor for input undervoltage protection. Pin 7 is the feedback pin, used to adjust the main output voltage. Pin 8 is the overvoltage detection protection pin for the low-voltage power supply winding; when the supply voltage is too high, the protection stops the drive, thus preventing chip damage due to excessive power supply. The high-voltage input power supply unit provides the start-up voltage to the auxiliary power source control unit, enabling it to start working and issue the drive. The low-voltage power supply winding unit maintains power supply after the auxiliary power source control unit is operating normally. The auxiliary power source control unit controls the entire auxiliary power source for normal operation. It should be further noted that any other components used to achieve the above effects should fall within the inventive concept of this utility model and should be protected within the scope of this utility model.

[0040] Example 1

[0041] An auxiliary power supply circuit for reducing power consumption through high-voltage input includes resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, and R26. 27. Resistor R27, 28. Resistor R29, 29. Resistor R30, 30. Capacitor C1, C2, C3, C4, C5, C6, C7, C8, D1, D2, D3, D4, D5, D6, Q1, Q2, Q3, Z1, Z2, Z3, Z4, Z5, Z5, U1, U6, PC1.

[0042] The first resistor, 10kΩ, is connected in series with pins 3 and 4 of the optocoupler. This first resistor acts as a current-limiting resistor to protect the optocoupler. The other end of the first resistor is connected to the gate of the switching transistor Q1 (JCS7N80FH-FB). The eighth, ninth, and tenth resistors R8, R9, and R10 are connected in series for voltage division. These resistors are 30kΩ carbon film resistors. The other end of the tenth resistor R10 is connected to the drain of the switching transistor Q1. The other end of the eighth resistor R8 is connected to the cathode of the first diode D1 (sampled by a UF5408) to prevent reverse voltage flow and is also connected to the positive terminal of the first capacitor C1 (1µA). F, the anode of the first diode D1 is connected to the port BUS+. The eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, the first Zener diode Z1, the second Zener diode Z2, the third Zener diode Z3, and the fourth Zener diode Z4 are connected in series to divide the voltage and clamp it. The eleventh resistor R11, the twelfth resistor R12, and the thirteenth resistor R13 are 1MΩ. The first Zener diode Z1, the second Zener diode Z2, and the third Zener diode Z3 are 15V Zener diodes, and the fourth Zener diode Z4 is a 27V Zener diode. The gate voltage of the switching transistor Q1 is stabilized at 27V, forming a 0-27V voltage drop with the source, which is used to control the conduction and turn-off of the switching transistor Q1.

[0043] Resistors R14, R15, R16, R17, R18, and R19 are connected in series for voltage division. Resistors R14, R15, R16, R17, and R18 are 510KΩ, and resistor R19 is 47KΩ. They are connected to port BUS-. Resistor R14 is connected to the cathode of diode D1. Resistors R18 and R19 are connected to pin 5 of the second chip U6 for input undervoltage protection. The second chip U6 is an OB2276ACPA-T. Resistor R19 is connected in parallel with the fifth Zener diode Z5 and the fourth capacitor C4. The fourth capacitor is 0.1uF and serves as a filter for interference suppression. The fifth Zener diode Z5 is a 6.2V Zener diode for clamping protection and also allows for a wider input voltage range, ensuring that the voltage division does not exceed the normal operating voltage range of the control chip pin.

[0044] The 24th resistor R24 ​​is connected in series with the 4th diode D4, and also in series with pins 5 and 6 of transformer T1. The 24th resistor R24 ​​is a 10Ω resistor. The 4th diode is an SS220A, used for rectification, outputting DC. The cathode of the 4th diode D4 is connected to the 7th capacitor C7, forming a rectifier-filter circuit. The 7th capacitor C7 is 100uF. The 2nd resistor R2 is connected in parallel with pins 1 and 2 of the 1st isolation optocoupler, and also in series with the 3rd resistor R3, the 4th resistor R4, and pins 2 and 3 of the 1st chip U1. The 2nd resistor R2 and the 4th resistor R4 are 1kΩ, and the 3rd resistor R3 is 3kΩ. The 1st isolation optocoupler is an EL1019 for signal isolation. The 1st chip U1 is an AZ431, with pin 1 of the 1st chip U1 connected between the 5th and 6th resistors. The 5th resistor R5 and the 6th resistor are connected in series for voltage division. R5 uses a 7.5K resistor, the sixth resistor R6 uses a 4.7K resistor, the other end of the fifth resistor and the other end of the third resistor are connected to the positive terminal of the seventh capacitor C7, the other end of the sixth resistor R6, the negative terminal of the seventh capacitor C7, and pin 2 of the first chip are connected to port BUS-. When the low-voltage power supply winding output voltage rises, the voltage at pin 1 of the first chip U1 rises to 2.5V with the voltage divider circuit, pins 2 and 3 of the first chip U1 conduct, and the first isolation optocoupler also conducts. At the same time, pins 3 and 4 of the first isolation optocoupler also conduct, pulling down the gate voltage of the first switching transistor, thereby turning off the first switching transistor, cutting off the high voltage input, and reducing the loss of the startup resistor; the other end of the third resistor R3 is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to pin 1 of the second chip U6. The third diode uses an IN4148W to prevent voltage backflow.

[0045] The cathode of the first diode D1 is connected to pin 1 of the first transformer T1. Pin 3 of the first transformer T1 is connected to the drain of the second switching transistor Q2. The second switching transistor Q2 is a CS6N90A0R-G, used as the main switch in the flyback circuit. The gate of the switching transistor Q1 is connected to one end of the twenty-ninth resistor R29 and one end of the twenty-seventh resistor R27. The other end of the twenty-ninth resistor R29 is connected to pin 3 of the second chip U6. The twenty-ninth resistor R29 is 22Ω and is used to adjust the conduction speed of the second switching transistor Q2. The twenty-seventh resistor R27 is 10kΩ. For grounding and discharge, pin 3 of the second chip U6 is simultaneously connected to pin 1 of the third switch Q3. Pin 3 of the third switch Q3 is connected to one end of the thirtieth resistor R30, and the other end is connected to the gate of the second switch Q2. Pin 2 of the third switch Q3, the other end of the twenty-seventh resistor R27, and the source of the second switch Q2 are connected to one end of the twenty-eighth resistor R28. The third switch Q3 is used to accelerate the turn-off of the second switch Q2. An LBSS5350SY3T1G is used. The thirtieth resistor R30 is 10Ω and is used to adjust the turn-off speed of the second switch Q2.

[0046] The 28th resistor, R28, is 400mΩ and is used for current sampling and overcurrent protection. One end of the 28th resistor is connected to one end of the 25th resistor. The other end of the 25th resistor is connected to pin 4 of the second chip U6, and also to the positive terminal of the fifth capacitor C5. The negative terminal of the fifth capacitor C5 and the other end of the 28th resistor are connected to port BUS-. The fifth capacitor C5 is 1000pF and is used for filtering and anti-interference. Pin 1 of the second chip U6 is connected to the positive terminal of the sixth capacitor C6 and pin 2 of the fifth diode. The negative terminal of the sixth capacitor C6 is connected to port BUS- and is 0.1uF, serving as a filter. Pin 3 of the fifth diode D5 is connected to the gate of the third switching transistor Q3, and pin 1 is connected to port BUS-. It is an LBAT54SLT1G diode used for clamping protection. Pin 6 of the second chip U6 is connected to one end of the 20th resistor R20, and the other end is connected to port BUS-. It is 100kΩ and is used for temperature detection and overtemperature protection. Pin 7 of the second chip U6 is connected to the feedback network U6_FB of the flyback main output, and also to the second capacitor C2 for filtering and anti-interference. Pin 8 of the second chip U6 is connected to one end of the twenty-third resistor R23, one end of the twenty-second resistor R22, and the positive terminal of the third capacitor C3. The twenty-second resistor R22 and the third capacitor C3 are connected in parallel, and the other end is connected to port BUS-. The twenty-second resistor R22 is 10kΩ, the third capacitor C3 is 100pF, and the twenty-third resistor R23 is 51kΩ. The other end of the twenty-third resistor R23 is connected between the fourth diode D4 and the twenty-fourth resistor R24 ​​for overvoltage protection. Pin 11 of the first transformer T1 is connected to the anode of the sixth diode D6. The cathode of the sixth diode is connected to the positive terminal of the eighth capacitor C8 and the port Vout. The negative terminal of the eighth capacitor is connected to pin 9 of the first transformer T1 and the port BAT-. The eighth capacitor C8 is 0.1uF and serves as a filter. VOUT is the main output. The high-voltage input power-saving auxiliary power supply circuit reduces losses and improves efficiency by cutting off high-voltage losses and providing low-voltage power supply. The circuit is simple and easy to understand, safe and reliable, and also low in cost, real-time and efficient, and easy to implement and promote.

[0047] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A power supply circuit for reducing power consumption through high-voltage input, characterized in that: Includes port BUS+, port BUS-, control chip U6, and optocoupler PC1; The port BUS+ is connected to the positive terminal of diode D1. The negative terminal of diode D1 is connected to one end of capacitor C1, one end of resistor R8, one end of resistor R11, one end of resistor R14, and pin 1 of transformer T1. The other end of capacitor C1 is connected to port BUS-. The other end of resistor R8 is connected to the drain of MOSFET Q1 via resistors R9 and R10. The source of MOSFET Q1 is connected to the positive terminal of diode D2. The negative terminal of diode D2 is connected to the negative terminal of diode D3 and pin 1 of control chip U6. The positive terminal of diode D3 is connected to one end of resistor R3, one end of resistor R5, one end of capacitor C7, and diode D14. The negative terminal of diode D4 is connected to port OVP and one end of resistor R24. The other end of resistor R24 ​​is connected to pin 6 of transformer T1. The other end of resistor R3 is connected to the anode of optocoupler PC1 and one end of resistor R2. The cathode of optocoupler PC1 is connected to the other end of resistor R2 and one end of resistor R4. The other end of resistor R4 is connected to pin 3 of chip U1. Pin 1 of chip U1 is connected to the other end of resistor R5 and one end of resistor R6. Pin 2 of chip U1 is connected to port BUS-, the other end of resistor R6, the other end of capacitor C7, and pin 5 of transformer T1. The other end of resistor R11 is connected to one end of resistor R12, the other end of resistor R12 is connected to one end of resistor R13, the other end of resistor R13 is connected to the cathode of Zener diode Z1, the anode of Zener diode Z1 is connected to the cathode of Zener diode Z2, the anode of Zener diode Z2 is connected to the cathode of Zener diode Z3, the anode of Zener diode Z3 is connected to the cathode of Zener diode Z4, the gate of MOSFET Q1 and one end of resistor R1, the other end of resistor R1 is connected to the collector of optocoupler PC1, and the anode of Zener diode Z4 is connected to the emitter of optocoupler PC1 and port BUS-. The other end of resistor R14 is connected to pin 5 of control chip U6 via resistors R15, R16, R17, and R18. Port OVP is connected to one end of resistor R23. The other end of resistor R23 is connected to one end of resistor R22, one end of capacitor C3, and pin 8 of control chip U6. Pin 6 of control chip U6 is connected to one end of resistor R20. Pin 5 of control chip U6 is connected to one end of capacitor C4, one end of resistor R19, and the cathode of Zener diode Z5. The other end of resistor R22 is connected to the other end of capacitor C3, the other end of resistor R20, the anode of Zener diode Z5, the other end of resistor R19, the other end of capacitor C4, and port BUS-. Pin 4 of the control chip U6 is connected to one end of capacitor C5 and one end of resistor R25. The other end of resistor R25 is connected to the collector of transistor Q3, one end of resistor R27, the source of MOSFET Q2, and one end of resistor R28. The other end of capacitor C5 is connected to pin 2 of the control chip U6, one end of capacitor C6, pin 1 of diode D5, the other end of resistor R28, and port BUS-. The other end of capacitor C6 is connected to pin 2 of diode D5 and pin 1 of the control chip U6. Pin 3 of the control chip U6 is connected to pin 3 of diode D5, one end of resistor R29, and the base of transistor Q3. The emitter of transistor Q3 is connected to one end of resistor R30. The other end of resistor R29 is connected to the other end of resistor R30, the other end of resistor R27, and the gate of MOSFET Q2. The drain of MOSFET Q2 is connected to pin 3 of transformer T1. Pin 11 of the transformer T1 is connected to the positive terminal of diode D6, the negative terminal of diode D6 is connected to one end of capacitor C8 and port VOUT, and pin 9 of the transformer T1 is connected to the other end of capacitor C8 and port BAT-.

2. The auxiliary power supply circuit for reducing power consumption with high-voltage input according to claim 1, characterized in that: The control chip U6 is IC-OB2276ACPA-T-SOP8.

3. The auxiliary power supply circuit for reducing power consumption with high-voltage input according to claim 1, characterized in that: The optocoupler PC1 is IC-EL1019-SMD4.

4. The auxiliary power supply circuit for reducing power consumption with high-voltage input according to claim 1, characterized in that: Pin 7 of the control chip U6 is connected to port U6_FB and one end of capacitor C2. The other end of capacitor C2 is connected to the other end of capacitor C3. Port U6_FB is connected to the feedback terminal of port VOUT.

5. The auxiliary power supply circuit for reducing power consumption with high-voltage input according to claim 1, characterized in that: The chip U1 is IC-AZ431-SOT23.

6. The auxiliary power supply circuit for reducing power consumption with high-voltage input according to claim 1, characterized in that: The diode D5 is a BAV99.

7. The auxiliary power supply circuit for reducing power consumption with high-voltage input according to claim 1, characterized in that: The transformer T1 has a shared coil between pins 9 and 11, a shared coil between pins 5 and 6, and a shared coil between pins 1 and 3.

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