High-energy-efficiency low-voltage large-current medical power supply circuit with PFC and synchronous rectification

Abstract

The utility model relates to a high-energy-efficiency low-voltage large-current medical power supply circuit with PFC and synchronous rectification. The high-energy-efficiency low-voltage large-current medical power supply circuit comprises a filtering sub-circuit, a lightning protection sub-circuit, a high-voltage starting sub-circuit, a commutator circuit, a PFC sub-circuit, a power conversion sub-circuit and a VCC power supply sub-circuit. A PFC and QRPWM controller sub-circuit; a secondary side power supply sub-circuit, a flyback synchronous rectification sub-circuit, a synchronous controller sub-circuit and an overvoltage feedback sub-circuit; according to the utility model, the solution of the AC-DC power supply with small volume, high energy efficiency and medium and large power natural heat dissipation is realized.

Description

Technical Field

[0001] The utility model relates to a switching power supply technology, in particular to a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification. Background Art

[0002] In the current fast-developing modern society, with the improvement of medical level, more and more advanced medical equipment is widely used in various medical occasions. Medical diagnosis, measurement and treatment equipment using AC power supply may cause leakage current due to improper grounding and electrical insulation, which may expose patients and medical personnel to potential dangers such as electric shock, burns, internal organ damage and arrhythmia. Therefore, most medical equipment now uses switching power supply. As an important part of medical equipment, power supply has more stringent requirements than other types of power supply products.

[0003] In view of the special use environment of medical equipment, medical power products have more stringent requirements in terms of safety and reliability. First of all, the insulation and leakage current requirements of medical industry standards must be met; secondly, the electromagnetic radiation and electromagnetic radiation protection of medical equipment are important parameter standards for medical equipment, involving surge and transient current strength, electrostatic discharge (ESD) level, and radio frequency interference (RFI) protection capabilities. Many medical applications involve RF therapeutic devices or non-invasive electronic surgical instruments, so the power supply must be able to resist interference and not be affected. There are also some special requirements for specific applications. For example, the system may be used in an ambulance, and voltage shocks may occur. This power supply must comply with the IEC68-2-29 standard; some equipment is portable and may be used in helicopters, so random vibrations will occur. This power supply should comply with the MIL-STD-810E standard.

[0004] Ordinary switching power supply is a capacitor input circuit, the phase difference between its current and voltage will cause the loss of exchange power, and the electromagnetic interference (EMl) and electromagnetic compatibility (EMC) problems caused by the serious distortion of the current waveform due to the capacitive load. Therefore, modern PFC technology is completely different from the power factor compensation technology of the past. It is adopted for the distortion of non-sinusoidal current waveform, forcing the AC line current to track the instantaneous change trajectory of the voltage waveform, and keeping the current and voltage in phase, so that the system is purely resistive technology (line current waveform correction technology) In order to meet the above-mentioned demanding standards, the switching power supply has the disadvantages of large size, low efficiency conversion, low power efficiency, small output current, narrow input voltage amplitude, and large output voltage ripple. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, so as to realize a small-volume, high-efficiency, medium-to-high-power natural heat dissipation AC-DC power supply solution.

[0006] The technical solution of the utility model to solve the above technical problems is as follows: a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification includes a filter subcircuit, a lightning protection subcircuit, a high-voltage start subcircuit, a rectifier subcircuit, a PFC subcircuit, a power conversion subcircuit, a VCC power supply subcircuit; a PFC, a QRPWM controller subcircuit; a secondary side power supply subcircuit, a flyback synchronous rectification subcircuit, a synchronous controller subcircuit, an overvoltage feedback subcircuit; and a current, voltage, and temperature feedback subcircuit. Based on the above technical solution, the utility model can also be improved as follows.

[0007] Furthermore, the filtering subcircuit includes an X capacitor C16, a common mode inductor LF2, an X capacitor C9, Y capacitors C8 and C17, a common mode inductor LF1, capacitors C1 and C3, and an inductor L1; further, the filtering subcircuit is mainly used to improve the electromagnetic compatibility of the system, improve EMI conduction and radiation, reduce the impact of power supply fluctuations on the system, and enhance the circuit working stability.

[0008] Furthermore, the lightning protection sub-circuit includes fuses FS1, FS2, and varistor ZNR1; further, the lightning protection sub-circuit is mainly used to protect other components in the circuit from damage. When the mains generates a high pulse voltage due to lightning strike or other factors, it will damage the components on the circuit. The function of this circuit is to transfer a large number of pulses generated by induced lightning strikes to the safety ground wire in a relatively short period of time, thereby protecting other components on the circuit.

[0009] Furthermore, the high-voltage starter subcircuit includes diodes D4 and D7 and resistors R23 and R24; further, the high-voltage starter subcircuit mainly functions to provide a small current to the controller through a large resistor before the power supply itself is started.

[0010] Furthermore, the rectifier circuit includes a bridge rectifier BD1, D3, and a high-voltage filter capacitor C18; further, the rectifier circuit mainly functions to convert the AC power of the mains into a unidirectional pulsating DC voltage.

[0011] Furthermore, the PFC subcircuit includes a Boot boost transformer LT1, a PFC control tube Q1, a capacitor C19, resistors R12, R13, R7, R10, and a diode D2; a PFC voltage division acquisition function formed by resistors R3, R6, R8, R15, R18, and capacitors C5, R31, and C14. Furthermore, the PFC subcircuit is used to improve the power factor of the power system and improve energy efficiency. In a traditional AC circuit, the active power demand of the load for the power supply is often small compared to the apparent power demand of the system. This leads to a decrease in power factor, resulting in unnecessary waste of electricity and an increase in network load; providing a relatively stable voltage to the power conversion circuit to improve the efficiency of power conversion; further, the PFC, QR PWM controller sub-circuit includes U2 PFC, QR PWM controller; further, the PFC, QR PWM controller sub-circuit mainly provides overvoltage, overcurrent, and temperature protection for the entire circuit and provides PWM control signals for the PFC circuit and the power conversion circuit, and is the core of the entire circuit.

[0012] Furthermore, the power conversion sub-circuit, the power transformer T1, C4, R1, R2, R4, R5, R9, R21, and D1 constitute an RDC absorption circuit, the QR control tube Q2, D5, R11, R14, and R17 constitute a QR control circuit, and R16, R35, and C15 constitute a QR voltage divider sampling function; further, the power conversion sub-circuit mainly converts the DC or AC voltage of the power supply into an electric energy output with different voltage, current or frequency, plays the role of isolating high voltage from low voltage, and avoids the risk of electric shock when using the low-voltage side power supply.

[0013] Furthermore, the VCC power supply sub-circuit includes rectifier tubes D10 and D11, filter capacitors C6 and C7, and resistor R19; further, the VCC power supply sub-circuit provides a stable voltage supply for the PFC and QR PWM controllers after the power supply is stably started, thereby reducing the interference of changes in the mains or load on the stable operation of the PWM controller.

[0014] Furthermore, the secondary side power supply electronic circuit includes a rectifier tube D15, current limiting resistors R38, R40, filter capacitors C37, C57, C35, C58, and a resistor R41, a transistor Q7, and a voltage regulator tube ZD5 that constitute a voltage stabilizing function device; further, the secondary side power supply electronic circuit has a main function of supplying power to the secondary side devices so that they can work normally.

[0015] Furthermore, the flyback synchronous rectifier circuit includes a synchronous rectifier tube Q8, resistors R42, R43, capacitor C36, diodes D16, D17; further, the flyback synchronous rectifier circuit mainly functions to improve the efficiency of energy conversion, reduce energy loss, and improve the power factor. Traditional diode rectification has a large conduction voltage drop and switching loss, resulting in low energy conversion efficiency. Synchronous rectification uses controllable switching devices to achieve lower conduction voltage drop and switching loss, thereby improving energy conversion efficiency.

[0016] Furthermore, the synchronous controller subcircuit includes a U6 synchronous controller and a resistor R32, capacitors C33, and C34; further, the synchronous controller subcircuit mainly detects the voltage output by the power converter and uses it as a synchronous detection signal, while outputting a PWM signal to control the flyback synchronous rectification circuit to achieve controllable switch rectification.

[0017] Furthermore, the overvoltage feedback subcircuit is composed of a voltage regulator ZD4, voltage-dividing resistors R37 and R39, and an optocoupler U1; further, the overvoltage feedback subcircuit mainly functions to monitor the output voltage so that the output voltage does not exceed the set voltage.

[0018] Furthermore, the current, voltage, and temperature feedback subcircuit includes an operational amplifier U5, resistors R47, R51, R48, R46, R55, R60, R59, R54, R57, R58, R56, R54, R49, R30, R45, J1, a temperature control switch RT2, an optocoupler U3, capacitors C41, C42, C46, ​​C53, C54, C56, C55, C52, C44, an optocoupler U3, and diodes D14 and D16; further, the current, voltage, and temperature feedback circuit mainly functions to feed back the output voltage and current to the PFC and QR PWM controllers so that they can dynamically control and adjust the changes in the output voltage, and can protect the circuit from damage according to the output voltage, current and circuit temperature.

[0019] The beneficial effect of taking the above steps is: through the functional combination of the lightning protection sub-circuit, the filtering sub-circuit, the high-voltage starting sub-circuit, the rectifier sub-circuit, the PFC sub-circuit, the power conversion sub-circuit, the VCC power supply sub-circuit; the PFC, QRPWM controller sub-circuit; the secondary side power supply sub-circuit, the flyback synchronous rectifier sub-circuit, the synchronous controller sub-circuit, the overvoltage feedback sub-circuit; the current, voltage and temperature feedback sub-circuit, a high-efficiency, low-voltage and high-current medical power supply with PFC and synchronous rectification is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram showing the structure of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to the utility model.

[0021] Figure 2 The utility model discloses a filter subcircuit circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0022] Figure 3 The utility model discloses a lightning protection subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0023] Figure 4 The utility model discloses a high-voltage starter circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0024] Figure 5 The utility model discloses a rectifier circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0025] Figure 6 The utility model discloses a PFC subcircuit circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0026] Figure 7 The utility model discloses a power conversion subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0027] Figure 8 The utility model discloses a VCC power supply subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0028] Fig. 9 The utility model discloses a circuit diagram of a PFC and QRPWM controller subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0029] Fig.10 The utility model discloses a circuit diagram of a secondary side power supply electronic circuit of a high energy efficiency, low voltage and high current medical power supply circuit with PFC and synchronous rectification.

[0030] Fig.11 The utility model discloses a flyback synchronous rectifier subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0031] Fig.12 The utility model discloses a synchronous controller subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0032] Fig.13The utility model discloses an overvoltage feedback subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification.

[0033] Fig.14 The utility model discloses a circuit diagram of a current, voltage and temperature feedback subcircuit of a high-efficiency, low-voltage and high-current medical power supply circuit with PFC and synchronous rectification. DETAILED DESCRIPTION

[0034] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0035] like Figure 1 As shown, a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification includes a filtering subcircuit, a lightning protection subcircuit, a high-voltage starting subcircuit, a rectifier subcircuit, a PFC subcircuit, a power conversion subcircuit, and a VCC power supply subcircuit; a PFC and QRPWM controller subcircuit; a secondary side power supply subcircuit, a flyback synchronous rectification subcircuit, a synchronous controller subcircuit, and an overvoltage feedback subcircuit; and a current, voltage, and temperature feedback subcircuit. The lightning protection subcircuit is connected to the filtering subcircuit; one end of the filtering subcircuit is connected to the lightning protection subcircuit, and the other end is connected to the high-voltage starting subcircuit; the high-voltage starting subcircuit is respectively connected to the rectifier subcircuit, the filtering subcircuit, the PFC, and the QRPWM controller subcircuit; the rectifier subcircuit is connected to the PFC subcircuit and the high-voltage starting subcircuit; the PFC subcircuit is connected to the power conversion subcircuit, the PFC, the QRPWM controller subcircuit, and the rectifier subcircuit; the VCC power supply subcircuit is respectively connected to the synchronous control subcircuit, the PFC, and the QRPWM controller subcircuit; the PFC and QRPWM controller subcircuit is connected to the VCC power supply subcircuit, the power conversion subcircuit, the PFC subcircuit, the high-voltage starting subcircuit, the overvoltage feedback subcircuit, and the current, voltage, and temperature feedback subcircuit; the power conversion subcircuit is connected to the PFC subcircuit, the PF C, QRPWM controller sub-circuit, VCC power supply sub-circuit, flyback synchronous rectifier sub-circuit, secondary power supply sub-circuit, synchronous control sub-circuit are connected; the secondary power supply sub-circuit is respectively connected to the synchronous control sub-circuit, power conversion sub-circuit, and flyback synchronous rectifier sub-circuit; the synchronous control sub-circuit is respectively connected to the secondary power supply sub-circuit, power conversion sub-circuit, and flyback synchronous rectifier sub-circuit; the flyback synchronous rectifier sub-circuit is respectively connected to the secondary power supply sub-circuit, power conversion sub-circuit, synchronous control sub-circuit, overvoltage feedback sub-circuit, current, voltage, and temperature feedback sub-circuit; the overvoltage feedback sub-circuit is respectively connected to the flyback synchronous rectifier sub-circuit, PFC, and QRPWM controller sub-circuit; the current, voltage, and temperature feedback sub-circuit is respectively connected to the flyback synchronous rectifier sub-circuit, PFC, and QRPWM controller sub-circuit.

[0036] like Figure 2As shown, a filtering subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, C16 is connected in parallel with pins 1 and 3 of LF2; one end of C8 is connected to pin 2 of LF2, and the other end is grounded; one end of C17 is connected to pin 4 of LF2, and the other end is connected to the X7 signal; one end of C9 is connected to C8, and the other end is connected to C9.

[0037] like Figure 3 As shown, a lightning protection subcircuit of a high-efficiency, low-voltage, and high-current medical power supply circuit with PFC and synchronous rectification, one end of FS1 is connected to one end of ZNR1, and the other end is connected to the CN1 terminal; one end of FS2 is connected to one end of ZNR1, and the other end is connected to the CN1 terminal.

[0038] like Figure 4 As shown, a high-voltage starter circuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, one end of D4 is connected to one end of LF2, the other end is connected to one end of D7, the other end of D7 is connected to one end of LF2, wherein the junction point of D4 and D7 is connected to one end of R23, the other end of R23 is connected to R24, and the other end of R24 is connected to pin 1 of U2.

[0039] like Figure 5 As shown, a rectifier circuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, BD1 pin 1 is connected to one end of L1, pin 2 is connected to pin 1 of LF1, pin 3 is connected to pin 3 of LF1, pin 4 is connected to one end of C18; one end of D3 is connected to one end of LT1, and the other end of D3 is connected to C18.

[0040] like Figure 6 As shown, a PFC sub-circuit circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, LT1 is connected to Q1; D2 and R7 are connected in series and then connected in parallel with R10, R13 is connected to one end of Q1, Q1 is connected in parallel with C19, one end of R12 is grounded and the other end is connected to Q1 and the PFCCS signal; R3, R6, R8, R15, and R18 are connected in series, one end of C5 is connected to the PFCINV signal and one end of R15, and the other end is grounded; R31 is connected in series with C14, the middle node is connected to pin 12 of U2, and the other end of R31 is connected to the PFCCS signal.

[0041] like Figure 7As shown, a power conversion subcircuit circuit diagram of a high-efficiency, low-voltage, and high-current medical power supply circuit with PFC and synchronous rectification, R1 and R4 are connected in parallel and then in series with R4 and R5, and then in parallel with C4; R9 and R21 are connected in parallel and then in series with C4; the other ends of R9 and R21 are connected to D1, the other end of D1 is connected to pin 1 of T1, pin 3 of T1 is connected to one end of C4, pin 5 of T1 is connected to one end of D10, and pin 6 of T1 is grounded; one end of D1 is connected to Q2 and one end of C20, the other end of C20 is connected to one end of Q2 and then connected to R16, and the other end of R16 is grounded; R11 is connected in series with D5, the other end of R11 is connected to Q2, R14 is connected in parallel with D5 and R11, and the other end of R14 is connected to one end of R17 , the other end of R17 is grounded; one end of R35 is connected to the QRCS signal, and the other end is connected to C15 and pin 11 of U2, and the other end of C15 is grounded; pin 4 of U2 is connected to the PRT signal, pin 5 is connected to the OVP signal, pin 6 is connected to one end of R26 and C13 respectively, the other end of R26 is connected to C12, and the other end of C12 is grounded; the other end of C13 is grounded; pin 7 of U2 is connected to one end of R28, and the other end of R28 is grounded; pin 8 of U2 is connected to one end of R29, and the other end of R29 is connected to the ZCD signal; pin 9 of U2 is connected to the PFCINV signal; pin 10 of U2 is connected to one end of R27, and the other end of R27 is grounded; pins 13, 14, 15, and 16 of U2 are connected to the PFCGATE signal, QRGATE signal, ground, and VCC respectively.

[0042] like Figure 8 As shown, a VCC power supply subcircuit circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, D10 and D11 are connected in series, R19 is connected to C7 and C6, the other end of R19 is connected to VCC, and the other end of C7 and C6 is connected in parallel and grounded.

[0043] like Fig. 9 As shown, a PFC, QRPWM controller sub-circuit circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification includes a U2 chip.

[0044] like Fig.10As shown, a secondary side power supply circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, one end of D15 is connected to the Aux signal, and the other end is connected to one end of R38 and R40 that are already connected in parallel, the other end of R38 and R40 is connected to one end of C37 and C57 that are already connected in parallel, and the other end of C37 and C57 is grounded; R41 and pin 2 of Q7 are connected to one end of C57, the other end of R41 and pin 1 of Q7 are connected to one end of ZD5, and the other end of ZD5 is grounded; pin 3 of Q7 and one end of C35 are connected and connected to the VDD signal, and the other end of C35 is grounded; C35 and C58 are connected in parallel.

[0045] like Fig.11 As shown, a flyback synchronous rectifier circuit diagram of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, R44 and D17 are connected in parallel, wherein one end of the parallel connection is connected to the GATE signal, and the other end is connected to R43 and one end of D16, D43 and D16 are connected in parallel and the other end is grounded; R42 and C36 are connected in series and then connected in parallel with the two pins of Q2, and the other end of Q8 is connected to D16.

[0046] like Fig.12 As shown, a circuit diagram of a synchronous controller subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, tube No. 1 of U6 is connected to one end of R34, and pin No. 2 of U6 is grounded; pin No. 3 of U6 is connected to one end of R32, and the other end of R32 is grounded; pin No. 4 of U6 is connected to one end of C33 and C34 in parallel, and the other ends of C33 and C34 are grounded; pin No. 5 of U6 is connected to the GATE signal; pin No. 6 of U6 is connected to the SRS signal.

[0047] like Fig.13 As shown, a circuit diagram of an overvoltage feedback subcircuit of a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, one end of ZD4 is connected to one end of R34, and the other end is connected to one end of R37, and the other end of R37 is connected to R39 and pin 1 of U1; the other end of R39 is connected to pin 2 of U1 and ground.

[0048] like Fig.14As shown, a current, voltage and temperature feedback subcircuit of a high-efficiency, low-voltage and high-current medical power supply circuit with PFC and synchronous rectification, one end of J1 is connected to one end of R59, and the other end is connected to ground; the other end of R59 is connected to pin 6 of U5; R45, R49 and R30 are connected in series and connected to pin 2 of U5 at one end of R49; pin 1 of U5 is connected to one end of C42, and the other end of C42 is grounded; pin 2 of U5 is also connected to Connect one end of R47 and R51, and the other end of R47 and R51 is grounded; Pin 2 of U5 is also connected to one end of R48 and C41, R48 and C41 are connected in parallel; R46 is connected to one end of R48, and the other end is connected to one end of RT2, and the other end of RT2 is connected to one end of R54 and Pin 3 of U5, and the other end of R54 is connected to VDD; Pin 3 of U5 is also connected to one end of C44, and the other end of C44 is connected to VDD. Ground; U5 pin 7 is connected to C46, ​​the other end of C46 is connected to R55, the other end of R55 is connected to U5 pin 6; U5 pin 8 is connected to VDD and one end of C53, the other end of C53 is connected to ground; U5 pin 7 is also connected to one end of R57, the other end of R57 is connected to one end of C54, the other end of C54 is connected to ground, D14 is connected to one end of R57, the other end of D17 is connected to one end of D18, and the two cross-connections are connected. Point is connected to one end of C55, and the other end of C55 is connected to ground; C55 is also connected to pin 2 of U3, pin 1 of U3 is connected to one end of C56, and the other end of C56 is grounded, C56 is also connected to one end of R60, and the other end of R60 is connected to VDD; pin 1 of U5 is connected to one end of R58 and R56, the other end of R58 is connected to one end of D18, the other end of R56 is connected to one end of C52, and the other end of C52 is connected to pin 2 of U5.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification, characterized in that: It includes filtering sub-circuit, lightning protection sub-circuit, high-voltage starting sub-circuit, rectifier sub-circuit, PFC sub-circuit, power conversion sub-circuit, VCC power supply sub-circuit; PFC, QRPWM controller sub-circuit; secondary side power supply sub-circuit, flyback synchronous rectifier sub-circuit, synchronous controller sub-circuit, overvoltage feedback sub-circuit; current, voltage and temperature feedback sub-circuit.

2. According to claim 1, a high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification is characterized in that: The lightning protection subcircuit is connected to the filtering subcircuit; one end of the filtering subcircuit is connected to the lightning protection subcircuit, and the other end is connected to the high-voltage starting subcircuit; the high-voltage starting subcircuit is respectively connected to the rectifier subcircuit, the filtering subcircuit, and the PFC and QRPWM controller subcircuits; the rectifier subcircuit is connected to the PFC subcircuit and the high-voltage starting subcircuit; the PFC subcircuit is connected to the power conversion subcircuit, the PFC and QRPWM controller subcircuit, and the rectifier subcircuit; the VCC power supply subcircuit is respectively connected to the synchronous control subcircuit, the PFC and QRPWM controller subcircuit; the PFC and QRPWM controller subcircuit is connected to the VCC power supply subcircuit, the power conversion subcircuit, the PFC subcircuit, the high-voltage starting subcircuit, the overvoltage feedback subcircuit, and the current, voltage, and temperature feedback subcircuit; the power conversion subcircuit is connected to the PFC subcircuit, the P The FC, QRPWM controller sub-circuit, VCC power supply sub-circuit, flyback synchronous rectifier sub-circuit, secondary power supply sub-circuit, and synchronous control sub-circuit are connected; the secondary power supply sub-circuit is respectively connected to the synchronous control sub-circuit, the power conversion sub-circuit, and the flyback synchronous rectifier sub-circuit; the synchronous control sub-circuit is respectively connected to the secondary power supply sub-circuit, the power conversion sub-circuit, and the flyback synchronous rectifier sub-circuit; the flyback synchronous rectifier sub-circuit is respectively connected to the secondary power supply sub-circuit, the power conversion sub-circuit, and the synchronous control sub-circuit, the overvoltage feedback sub-circuit, and the current, voltage, and temperature feedback sub-circuit; the overvoltage feedback sub-circuit is respectively connected to the flyback synchronous rectifier sub-circuit, PFC, and QRPWM controller sub-circuit; the current, voltage, and temperature feedback sub-circuit is respectively connected to the flyback synchronous rectifier sub-circuit, PFC, and QRPWM controller sub-circuit.

3. The high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The filtering subcircuit includes an X capacitor C16, a common mode inductor LF2, an X capacitor C9, Y capacitors C8 and C17, a common mode inductor LF1, capacitors C1 and C3, and an inductor L1.

4. The high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The lightning protection sub-circuit includes fuses FS1 and FS2 and a varistor ZNR1; the high-voltage starter sub-circuit includes diodes D4 and D7 and resistors R23 and R24.

5. The high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The rectifier subcircuit includes a bridge stack BD1, D3, and a high-voltage filter capacitor C18; the PFC subcircuit includes a Boot boost transformer LT1, a PFC control tube Q1, a capacitor C19, resistors R12, R13, R7, R10, and a diode D2; and a PFC voltage division acquisition function composed of resistors R3, R6, R8, R15, R18, and capacitors C5, R31, and C14.

6. The high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The PFC, QR PWM controller subcircuit includes U2 PFC, QR PWM controller; the power conversion subcircuit, power transformer T1, C4, R1, R2, R4, R5, R9, R21, D1 constitute an RDC absorption circuit, QR control tube Q2, D5, R11, R14, R17 constitute a QR control circuit, R16, R35, C15 constitute a QR voltage divider sampling function.

7. A high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The VCC power supply sub-circuit includes rectifier tubes D10 and D11, filter capacitors C6 and C7, and resistor R19; the secondary side power supply sub-circuit includes rectifier tube D15, current limiting resistors R38 and R40, filter capacitors C37, C57, C35, C58, and resistor R41, transistor Q7, and voltage regulator tube ZD5 constituting voltage stabilization function devices.

8. The high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The flyback synchronous rectifier subcircuit includes a synchronous rectifier tube Q8, resistors R42, R43, capacitor C36, diodes D16, D17; the synchronous controller subcircuit includes a U6 synchronous controller and a resistor R32, capacitors C33, C34.

9. The high-efficiency, low-voltage, high-current medical power supply circuit with PFC and synchronous rectification according to claim 1, characterized in that: The overvoltage feedback subcircuit is composed of a voltage regulator tube ZD4, voltage-dividing resistors R37 and R39, and an optocoupler U1; the current, voltage, and temperature feedback subcircuit includes an operational amplifier U5, resistors R47, R51, R48, R46, R55, R60, R59, R54, R57, R58, R56, R54, R49, R30, R45, J1, a temperature control switch RT2, an optocoupler U3, capacitors C41, C42, C46, ​​C53, C54, C56, C55, C52, C44, an optocoupler U3, and diodes D14 and D16.

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