Intelligent constant-current constant-voltage switching power supply circuit capable of rapidly converting output voltage
By using an intelligent and fast constant current and constant voltage switching power supply circuit that switches the output voltage quickly, and utilizing the DIP switch SW1 to switch the circuit output voltage, the problems of large size, high cost and insufficient voltage output accuracy of existing landscape lighting switching power supplies are solved, and flexible adaptation of multi-channel voltage switching and equipment protection are achieved.
Patent Information
- Application Number
- CN202422550701.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-10-22
AI Technical Summary
Existing landscape lighting switching power supplies can only output in single or dual channels. They are bulky, expensive, and lack sufficient voltage output accuracy, making them difficult to adapt to devices with different voltages and increasing the risk of damage to peripheral equipment.
The constant current and constant voltage switching power supply circuit adopts intelligent fast output voltage conversion. The output voltage is switched by DIP switch SW1. Combined with EMC electromagnetic filtering, rectification filtering, PFC boost, LLC resonance, output synchronous rectification and output control circuit, the switching of different working voltages can be realized.
It enables flexible adaptation of multiple voltage switching channels, reduces the risk of equipment damage, improves voltage output accuracy and applicability, and reduces matching difficulty.
Smart Images
Figure CN223502747U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of switching power supply technology, specifically to an intelligent constant current and constant voltage switching power supply circuit that rapidly converts output voltage. Background Technology
[0002] Currently, commercially available switching power supplies for landscape lighting only support single or dual-channel simultaneous output, resulting in large size, high cost, and complex structure. When switching between multiple channels or a single channel is required, potentiometers in the circuit must be adjusted to change the output voltage. With traditional dual-channel output, changing the voltage of one channel also changes the voltage of the other, leading to insufficient voltage output accuracy and potential damage to peripheral equipment. With traditional single-channel output, the voltage application range is limited, increasing the matching difficulty for peripheral equipment used in outdoor landscape lighting. Therefore, based on these issues, further improvements to existing technology are necessary. Utility Model Content
[0003] In view of this, the purpose of this utility model is to provide an intelligent constant current and constant voltage switching power supply circuit that can quickly switch the output voltage. By switching the output voltage of the circuit through the DIP switch SW1, the switching of different working voltages can be realized, thereby adapting to devices with different voltages.
[0004] To solve the above-mentioned technical problems, the technical solution used in this utility model is as follows:
[0005] This utility model discloses an intelligent, fast-conversion constant current and constant voltage switching power supply circuit for output voltage, comprising an EMC electromagnetic filter circuit, a rectifier filter circuit, a PFC boost circuit, an LLC resonant circuit, an output synchronous rectifier circuit, an output control circuit, and an output voltage feedback circuit. The EMC electromagnetic filter circuit is connected to the power input terminal. One end of the rectifier filter circuit is connected to the EMC electromagnetic filter circuit, and the other end of the rectifier filter circuit is connected to one end of the PFC boost circuit. The other end of the PFC boost circuit is connected to the LLC resonant circuit, and the other end of the LLC resonant circuit is connected to the output synchronous rectifier circuit and the output voltage feedback circuit. The output synchronous rectifier circuit is also connected to the output control circuit, which is used to adjust the output voltage.
[0006] Preferably, the EMC electromagnetic filter circuit includes a fuse F1, a common mode inductor LF1, a common mode inductor LF2, a magnetic core inductor L1, capacitors C1, C2, C3, C4, and C8, a diode D7, and a diode D8; the rectifier filter circuit includes a rectifier bridge BD1 and a capacitor C5.
[0007] One end of fuse F1 is connected to the live wire, and the other end of fuse F1 is connected to one end of common mode inductor LF1. The other end of common mode inductor LF1 is connected to the neutral wire. Capacitor C1 is connected in parallel across the two ends of common mode inductor LF1. Capacitor C2, along with capacitors C3 and C4 connected in series, is connected in parallel between common mode inductor LF1 and common mode inductor LF2. The two ends of capacitor C2, one end of capacitor C3, and one end of capacitor C4 are respectively connected to common mode inductor LF1. The other ends of capacitor C3 and capacitor C4 are grounded through capacitor C8.
[0008] One end of the common-mode inductor LF2 is connected to the positive terminal of diode D7 and one input terminal of rectifier BD1. The other end of the common-mode inductor LF2 is connected to one end of the core inductor L1. The other end of the core inductor L1 is connected to the positive terminal of diode D8 and the other input terminal of rectifier BD1. The negative terminal of diode D7 is connected to the negative terminal of diode D8. The output terminal of rectifier BD1 is connected to the PFC boost circuit through capacitor C5.
[0009] Preferably, the PFC boost circuit includes chip U1, resistors R1, R2, R5, R10, R11, R12, R13, R14, R19, R20, R26, R29, R32, R33, R34, R38, R53, R54, R55, inductors L2A, L2B, and L4, switch S1, capacitors C10, C11, C12, C13, C14, C22, C23, C47, and C48, diodes D3, D9, and D12, transistor Q4, MOSFET Q1A, and MOSFET Q1.
[0010] One end of resistor R1 is connected to the cathodes of diodes D7 and D8. The other end of resistor R1 is connected in series with resistors R2, R14, and R5. One end of resistor R5 is connected to one end of capacitor C11 and one end of resistor R26. The other ends of capacitor C11 and resistor R26 are grounded. One end of resistor R5, one end of capacitor C11, and one end of resistor R26 are also connected to the LNS pin of chip U1.
[0011] The two output terminals of the rectifier BD1 are connected through capacitor C5. Capacitor C5 is also grounded through resistor R32. Resistor E33 is connected in parallel with resistor R32. Capacitor C5 is also grounded through resistor R29 and capacitor C12 connected in series. Resistor R32 is connected in parallel with resistor R29 and capacitor C12 connected in series. One end of resistor R29 and one end of capacitor C12 are connected to the CS pin of chip U1.
[0012] One output terminal of rectifier BD1 is also connected to one end of inductor L2A. The other end of inductor L2A is connected to ground in series with inductor L4, diode D9, and capacitor C23. Diode D9 is also connected to LLC resonant circuit. Diode D9 is also connected in series with resistors R19, R20, and R45. One end of resistor R45 is grounded through parallel resistors R34, R38, and capacitor C22. Resistor R45 and capacitor C22 are also connected to the FBB pin of chip U1. Resistors R19, R20, and R45 are connected in parallel with capacitor C23.
[0013] The capacitors C10, C13, C14 and C23 are connected in parallel; the inductor L2B and inductor L2A are connected in parallel; and the diode D12 is connected in parallel with inductor L2A, inductor L4 and diode D9.
[0014] Inductor L2A is also connected to the drain of MOSFET Q1A, one end of resistor R10, and one end of capacitor C48. The other end of resistor R10 is connected to the HV pin of chip U1. The other end of capacitor C48 is connected to the source of MOSFET Q1A through resistor R55. The source of MOSFET Q1A is grounded. Resistor R54 and capacitor C47 are connected in parallel with resistor R55.
[0015] The gate of MOSFET Q1A is connected to one end of resistor R12. The other end of resistor R12 is connected to the emitter of transistor Q4, one end of resistor R13, and one end of resistor R11. The collector of transistor Q4 is connected to the source of MOSFET Q1A. The base of transistor Q4 is connected to the anode of diode D3 and resistor R53. The cathode of diode D3 is connected to resistor R10. Resistor R53 is connected to the GATEB pin of chip U1. The other end of resistor R13 is grounded. The other end of R11 is connected to the gate of MOSFET Q1. The source of MOSFET Q1 is grounded. The drain of MOSFET Q1 is connected to inductor L2A.
[0016] Preferably, the LLC resonant circuit includes resistors R3, R4, R7, R15, R16, R17, R22, R23, R24, R25, R44, and R37; capacitors C6, C7, R8, C17, C18, C18, C30, C31, C32, C33, C35, and C49; inductors L3A and L3B; diodes D1, D2, D4, and D5; Zener diode ZD1; transistor Q5; MOSFET Q2 and Q3; diode D6; and transformer T2.
[0017] One end of resistor R23 is connected to the GATEH pin of chip U1, the other end of resistor R23 is connected to one end of resistor R22, the other end of resistor R22 is connected to one end of resistor R16 and the gate of MOSFET Q2, and diode D4 is connected in parallel with resistor R22.
[0018] The drain of MOSFET Q2 is connected to the cathode of diode D9, and the source of MOSFET Q2 is connected to the drain of MOSFET Q3. The source of MOSFET Q2 is connected to the ISEN pin of chip U1 through capacitor C31. The gate of MOSFET Q3 is connected in series with resistors R25 and R24 and the GATEL pin of chip U1. The gate of MOSFET Q3 is also connected to one end of resistor R17, and the other end of resistor R17 is connected to capacitor C31. The source of MOSFET Q2 is also connected to one end of inductor L3A and capacitor C4. One end of capacitor C49 is connected to the source of MOSFET Q3; the T2D winding of transformer T2 is connected to the other end of inductor L3A and one end of capacitors C32 and C33; the other end of capacitor C32 is connected to one end of resistor R37, one end of resistor R9 and one end of resistor R8; the other end of resistor R8 is grounded and the other ends of resistor R8, resistor R9 and capacitor C33 are all connected to capacitor C31; the other end of resistor R37 is connected to the ISEN pin of chip U1.
[0019] Capacitor C30 is also connected to the negative terminal of diode D2. The positive terminal of diode D2 is connected to the HS pin of chip U1 and is also connected to the negative terminal of diode D1, one end of capacitor C18, and one end of capacitor C7. The diode D1 is connected to the emitter of transistor Q5. The base of transistor Q5 is connected to the negative terminal of Zener diode ZD1 and one end of resistor R4. The collector of transistor Q5 is connected to the negative terminal of diode D6, the other end of resistor R4, and one end of capacitor C35. Transformer T2 is connected to the positive terminal of diode D6, the other end of capacitor C35, the other end of Zener diode ZD1, the other end of capacitor C7, and the other end of capacitor C18, and is connected to the VSEN pin of chip U1 through capacitor C6. Resistor R15 is connected in parallel with capacitor C6, and resistor R44 is connected between resistor R4 and capacitor C6. Windings T2A, T2B, and T2C of transformer T2 are all connected to the output synchronous rectifier circuit.
[0020] Preferably, the output synchronous rectification circuit includes capacitors C9, C20, C21, C24, C25, C26, C27, C28, C29, C34, C36, C37, C38, C39, C40, C41, and C45; resistors R31, R47, R46, R63, R64, R65, R66, R69, R70, R71, R72, R73, and RS1; diodes D11 and D10; Zener diode ZD2; MOSFETs Q8 and Q9; transistor Q10; and chip U3.
[0021] The winding T2A of transformer T2 is connected to the positive terminal of diode D10, one end of capacitor C29, and the rectification terminal of Zener diode ZD2. The negative terminal of diode D10 is connected to the other end of capacitor C29 and to an external power supply. The VO+ terminal of transformer T2 is also connected to one end of resistor R46 and the collector of transistor Q10. The other end of resistor R46 is connected to the base of transistor Q10. The emitter of transistor Q10 is connected to the positive terminal of diode D11. The negative terminal of diode D1 is connected to an external power supply.
[0022] The VO+ terminal of transformer T2 is connected in series with resistors R47 and RS1 and then grounded. Capacitor C45 is connected in parallel with the series resistors R47 and RS1. Capacitors C24, C23, C26, C27, C28, and resistor R31 are connected in parallel with resistor R7. Resistors R47 and RS1 are also connected to the winding T2A of transformer T2.
[0023] The winding T2A of the transformer T2 is also connected to one end of the capacitor C38, the source of the MOSFET Q8, the gate of the MOSFET Q8, the second pin of the chip U3, the fifth pin of the chip U3, and one end of the resistor R69. The other end of the resistor R69 is connected to the third pin of the chip U3. The capacitor C34 is connected in parallel with the resistor R69. The other end of the capacitor C38 is connected to the sixth pin of the chip U3 through the series resistors R7 and R63. The resistors R70 and R71 are connected in parallel. The drain of the MOSFET Q8 is also connected to the winding T2B of the transformer T2 and the resistor R7. The base of the MOSFET Q8 is also connected to the eighth pin of the chip U3 through the resistor R65.
[0024] The winding T2A of the transformer T2 is also connected to one end of the capacitor C39, the source of the MOSFET Q9, and the gate of the MOSFET Q9. The gate of the MOSFET Q9 is also connected to the gate of the MOSFET Q8 and one end of the resistor R66. The other end of the resistor R66 is connected to the first pin of the chip U3. The other end of the capacitor C39 is connected to the fourth pin of the chip U3 through the series resistors R73 and R64. The resistors R72 and R73 are connected in parallel. The drain of the MOSFET Q9 is also connected to the winding T2C of the transformer T2 and the resistor R73.
[0025] The fifth pin of chip U3 is also connected to the seventh pin of chip U3 through resistor C36. The capacitor C37 is connected in parallel with capacitor C36. The seventh pin of chip U3 is also connected to an external power supply.
[0026] Preferably, the output control circuit includes capacitors CX1, CX2, CX3, CX4, CX5, CX15, CX16, CX17, and CX18; resistors RX1, RX2, RX3, RX4, RX5, RX6, RX24, RX25, RX26, RX27, and RX28; a thermistor NX1; chips UX1, UX2, UX4, and UX5; an LED LD1; a Zener diode UX2; and a DIP switch SW1.
[0027] The first and third pins of chip UX1 are connected to the two ends of capacitor CX1. The first pin of chip UX1 is grounded, the second pin of chip UX1 is connected to an external power supply, capacitor CX2 is connected in parallel with capacitor CX1, and the third pin of chip UX1 is also connected to the VDD pin of chip UX4.
[0028] One end of the resistor RX3 is connected to the winding T2A of the transformer T2, and the other end of the resistor RX3 is connected to the VCS terminal of the chip UX4 through the series resistors RX4 and RX24. The capacitor CX4 is connected in parallel with the resistor RX4.
[0029] The first pin of the chip UX5 is connected to resistors RX4 and RX24. The second and third pins of the chip UX5 are grounded. The third pin of the chip UX5 is also connected to one end of capacitor CX18 and one end of capacitor CX15. The other end of capacitor CX18 is connected to resistor RX3. The other end of capacitor CX15 is connected to the VCS terminal of the chip UX4.
[0030] One end of the resistor RX26 is connected to the LLC resonant circuit, and the other end of the resistor RX26 is connected to one end of the resistor RX27 and the VOS pin of the chip UX4. The other end of the resistor RX27 is grounded, and the capacitor CX16 is connected in parallel with the resistor RX27.
[0031] One end of the thermistor NX1 is connected to the fifth pin of the chip UX5, and the other end of the thermistor NX1 is connected to the VTS pin of the chip UX4 and one end of the resistor RX28. The other end of the resistor RX28 is grounded. The resistor RX25 is connected in parallel with the thermistor NX1, and the capacitor CX17 is connected in parallel with the resistor RX28.
[0032] One end of resistor RX15 is connected to an external power supply, the other end of resistor RX15 is connected to the VAS pin of chip UX4 and one end of resistor RX6, the other end of resistor RX6 is grounded, and capacitor CX5 is connected in parallel with resistor RX6.
[0033] One end of resistor RX1 is connected to the LEDG pin of chip UX4, and the other end of resistor RX1 is connected to the positive terminal of light-emitting diode LD1, while the negative terminal of light-emitting diode LD1 is grounded; one end of resistor RX2 is connected to the VDD pin of chip UX4, and the other end of resistor RX2 is connected to the first pin of chip UX2, the second pin of chip UX2 is grounded, the third pin of chip UX2 is connected to the ninth pin of chip UX4, and capacitor CX3 is connected in parallel with chip UX2.
[0034] Pins 1, 2, 3, and 4 of DIP switch SW1 are grounded. Pin 5 of DIP switch SW1 is connected to pin SB4 of chip UX4. Pin 6 of DIP switch SW1 is connected to pin SB3 of chip UX4. Pin 7 of DIP switch SW1 is connected to pin SB2 of chip UX4. Pin 8 of DIP switch SW1 is connected to pin SB5 of chip UX4.
[0035] Preferably, the output voltage feedback circuit includes an optocoupler U2, resistors RX8 and RX, diodes DX1B and DX1A, resistors RX10, RX11, RX12, RX13, RX14, RX15, RS16, RX17, RS18, RX19, RX20, RX21, RX22, RX23, RX29, capacitors CX6, CX8, CS9, CX10, CX11, CX12, CX13, CX14, and an operational amplifier UX6.
[0036] One end of resistor RX29 is connected to the VDD terminal of chip UX4, and the other end of resistor RX29 is grounded through capacitor CX6. The other end of resistor RX29 is connected to the VDA pin of chip UX5, the eighth pin of operational amplifier UX6, and one end of resistor RX8. The other end of resistor RX8 is connected to one end of resistor RX9, and the other end of resistor RX9 is connected to the anode of diode DX1B and the anode of diode DX1A.
[0037] The negative terminal of diode DX1B is connected to the seventh pin of the operational amplifier. The seventh pin of the operational amplifier UX6 is also connected to the sixth pin of the operational amplifier UX6 through resistor RX10 and capacitor CX8. The sixth pin of the operational amplifier UX6 is connected to one end of resistor RX17, one end of capacitor CX12, and one end of resistor RX19. The other end of capacitor CX12 is connected to one end of resistor RX18. The other ends of resistors RX17 and RX18 are connected to the VO+ terminal of transformer T2. The other end of resistor RX19 is grounded. The fifth pin of the operational amplifier UX6 is grounded through resistor RX15. Capacitor CX11 is connected in parallel with resistor RX15. The fifth pin of the operational amplifier UX6 is also connected to the VDD pin of chip UX4 through resistors RX14, RX21, and RX20 connected in series. Resistors RX21 and RX20 are also connected to the PWMA pin of chip UX4. Resistors RX14 and RX21 are grounded through capacitor CX13.
[0038] The positive terminal of diode DX1A is connected to the first pin of operational amplifier UX6. The first pin of operational amplifier UX6 is connected to the second pin of operational amplifier UX6 through resistor RX11 and capacitor CX9. The second pin of operational amplifier UX6 is grounded through resistor RX12. The third pin of operational amplifier UX6 is connected to the VDD pin of chip UX4 through resistors RX16, RX23, and RX22 connected in series. Resistors RX23 and RX22 are also connected to the PWMB pin of chip UX4. Resistors RX16 and RX23 are grounded through capacitor CX14.
[0039] The fourth pin of the operational amplifier UX6 is connected to the winding T2A of the transformer T2 through a series capacitor CX10 and a resistor RX13; one end of the optocoupler U2 is connected to both ends of the resistor RX8, and the other end of the optocoupler U2 is connected to both ends of the capacitor C17; the capacitor CX7 is connected in parallel with the resistor RX9.
[0040] Preferably, it also includes a surge protection circuit, which includes an impedance Z1, a thermistor N1, and a relay K1.
[0041] The impedance Z1 and capacitor C2 are connected in parallel across the common-mode inductor LF1. The relay K1 is connected between the other end of the common-mode inductor LF2 and one end of the magnetic core inductor L1. The relay K1 is also connected to one input terminal of the rectifier BD1 in the EMC electromagnetic filter circuit. The relay K1 is also connected to the LLC resonant circuit through resistor R7.
[0042] Compared with existing technologies, the main advantages of the intelligent, fast-conversion constant current and constant voltage switching power supply circuit of this utility model are as follows:
[0043] The UX4 chip is connected to resistors of different values. The DIP switch SW1 controls the grounding of the SB4, SB3, SB2 and SB5 pins of the UX4 chip, thereby controlling the output voltage of the switching power supply circuit. When the SB2 pin of the UX4 chip is grounded, the SB2 pin and the PWMA pin of the UX4 chip output one operating voltage. When the SB3 pin of the UX4 chip is grounded, the SB3 pin and the PWMB pin of the UX4 chip output another operating voltage. When the SB4 pin of the UX4 chip is grounded, the SB4 pin and the LEDG pin of the UX4 chip output yet another operating voltage.
[0044] Meanwhile, the GATEL pin of chip U1 is connected to capacitor C33. Chip U1 detects the voltage level on capacitor C33. When the voltage of capacitor C33 exceeds the rated value, chip U1 disconnects from MOSFET Q2, MOSFET Q3, and transistor Q5, and stops supplying power to transformer T2, thereby achieving overcurrent protection and overpower protection.
[0045] This invention uses a DIP switch SW1 to switch the output voltage of the circuit, thereby enabling the switching of different operating voltages and making it compatible with devices with different voltages. Attached Figure Description
[0046] The above and other objects, features, and advantages of this invention will become clearer through a more detailed description of the preferred embodiments shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally drawn to scale with actual dimensions; the focus is on illustrating the gist of this invention.
[0047] Figure 1 This is a schematic diagram of the present invention.
[0048] Figure 2 This is a schematic diagram of the EMC electromagnetic filter circuit, surge protection circuit, rectifier filter circuit, PFC boost circuit, LLC resonant circuit, and output synchronous rectifier circuit in this utility model.
[0049] Figure 3This is a schematic diagram of the output control circuit and the output voltage feedback circuit in this utility model. Detailed Implementation
[0050] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand this utility model and implement it. However, the embodiments are not intended to limit this utility model. In this embodiment, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this utility model.
[0051] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to and integrated with the other element, or there may be an intervening element present. The terms "mounted," "one end," "the other end," and similar expressions used in this invention are for illustrative purposes only.
[0052] This embodiment provides an intelligent, fast-conversion constant current / constant voltage switching power supply circuit, such as... Figure 1-3 As shown, it includes an EMC electromagnetic filter circuit, a rectifier filter circuit, a PFC boost circuit, an LLC resonant circuit, an output synchronous rectifier circuit, an output control circuit, and an output voltage feedback circuit. The EMC electromagnetic filter circuit is connected to the power input terminal. One end of the rectifier filter circuit is connected to the EMC electromagnetic filter circuit, and the other end of the rectifier filter circuit is connected to one end of the PFC boost circuit. The other end of the PFC boost circuit is connected to the LLC resonant circuit, and the other end of the LLC resonant circuit is connected to the output synchronous rectifier circuit and the output voltage feedback circuit. The output synchronous rectifier circuit is also connected to the output control circuit, which is used to adjust the output voltage.
[0053] The EMC electromagnetic filter circuit includes a fuse F1, common mode inductors LF1 and LF2, a magnetic core inductor L1, capacitors C1, C2, C3, C4, and C8, and diodes D7 and D8; the rectifier filter circuit includes a rectifier bridge BD1 and capacitor C5.
[0054] One end of fuse F1 is connected to the live wire, and the other end of fuse F1 is connected to one end of common mode inductor LF1. The other end of common mode inductor LF1 is connected to the neutral wire. Capacitor C1 is connected in parallel across the two ends of common mode inductor LF1. Capacitor C2, along with capacitors C3 and C4 connected in series, is connected in parallel between common mode inductor LF1 and common mode inductor LF2. The two ends of capacitor C2, one end of capacitor C3, and one end of capacitor C4 are respectively connected to common mode inductor LF1. The other ends of capacitor C3 and capacitor C4 are grounded through capacitor C8.
[0055] One end of the common-mode inductor LF2 is connected to the positive terminal of diode D7 and one input terminal of rectifier BD1. The other end of the common-mode inductor LF2 is connected to one end of the core inductor L1. The other end of the core inductor L1 is connected to the positive terminal of diode D8 and the other input terminal of rectifier BD1. The negative terminal of diode D7 is connected to the negative terminal of diode D8. The output terminal of rectifier BD1 is connected to the PFC boost circuit through capacitor C5.
[0056] The PFC boost circuit includes chip U1, resistors R1, R2, R5, R10, R11, R12, R13, R14, R19, R20, R26, R29, R32, R33, R34, R38, R53, R54, R55, inductors L2A, L2B, and L4, switch S1, capacitors C10, C11, C12, C13, C14, C22, C23, C47, and C48, diodes D3, D9, and D12, transistor Q4, MOSFET Q1A, and MOSFET Q1. In this embodiment, chip U1 is model SY5055.
[0057] One end of resistor R1 is connected to the cathodes of diodes D7 and D8. The other end of resistor R1 is connected in series with resistors R2, R14, and R5. One end of resistor R5 is connected to one end of capacitor C11 and one end of resistor R26. The other ends of capacitor C11 and resistor R26 are grounded. One end of resistor R5, one end of capacitor C11, and one end of resistor R26 are also connected to the LNS pin of chip U1.
[0058] The two output terminals of the rectifier BD1 are connected through capacitor C5. Capacitor C5 is also grounded through resistor R32. Resistor E33 is connected in parallel with resistor R32. Capacitor C5 is also grounded through resistor R29 and capacitor C12 connected in series. Resistor R32 is connected in parallel with resistor R29 and capacitor C12 connected in series. One end of resistor R29 and one end of capacitor C12 are connected to the CS pin of chip U1.
[0059] One output terminal of rectifier BD1 is also connected to one end of inductor L2A. The other end of inductor L2A is connected to ground in series with inductor L4, diode D9, and capacitor C23. Diode D9 is also connected to LLC resonant circuit. Diode D9 is also connected in series with resistors R19, R20, and R45. One end of resistor R45 is grounded through parallel resistors R34, R38, and capacitor C22. Resistor R45 and capacitor C22 are also connected to the FBB pin of chip U1. Resistors R19, R20, and R45 are connected in parallel with capacitor C23.
[0060] The capacitors C10, C13, C14 and C23 are connected in parallel; the inductor L2B and inductor L2A are connected in parallel; and the diode D12 is connected in parallel with inductor L2A, inductor L4 and diode D9.
[0061] Inductor L2A is also connected to the drain of MOSFET Q1A, one end of resistor R10, and one end of capacitor C48. The other end of resistor R10 is connected to the HV pin of chip U1. The other end of capacitor C48 is connected to the source of MOSFET Q1A through resistor R55. The source of MOSFET Q1A is grounded. Resistor R54 and capacitor C47 are connected in parallel with resistor R55.
[0062] The gate of MOSFET Q1A is connected to one end of resistor R12. The other end of resistor R12 is connected to the emitter of transistor Q4, one end of resistor R13, and one end of resistor R11. The collector of transistor Q4 is connected to the source of MOSFET Q1A. The base of transistor Q4 is connected to the anode of diode D3 and resistor R53. The cathode of diode D3 is connected to resistor R10. Resistor R53 is connected to the GATEB pin of chip U1. The other end of resistor R13 is grounded. The other end of R11 is connected to the gate of MOSFET Q1. The source of MOSFET Q1 is grounded. The drain of MOSFET Q1 is connected to inductor L2A.
[0063] The LLC resonant circuit includes resistors R3, R4, R7, R15, R16, R17, R22, R23, R24, R25, R44, and R37; capacitors C6, C7, R8, C17, C18, C18, C30, C31, C32, C33, C35, and C49; inductors L3A and L3B; diodes D1, D2, D4, and D5; Zener diode ZD1; transistor Q5; MOSFET Q2 and Q3; diode D6; and transformer T2.
[0064] One end of resistor R23 is connected to the GATEH pin of chip U1, the other end of resistor R23 is connected to one end of resistor R22, the other end of resistor R22 is connected to one end of resistor R16 and the gate of MOSFET Q2, and diode D4 is connected in parallel with resistor R22.
[0065] The drain of MOSFET Q2 is connected to the cathode of diode D9, and the source of MOSFET Q2 is connected to the drain of MOSFET Q3. The source of MOSFET Q2 is connected to the ISEN pin of chip U1 through capacitor C31. The gate of MOSFET Q3 is connected in series with resistors R25 and R24 and the GATEL pin of chip U1. The gate of MOSFET Q3 is also connected to one end of resistor R17, and the other end of resistor R17 is connected to capacitor C31. The source of MOSFET Q2 is also connected to one end of inductor L3A and capacitor C4. One end of capacitor C49 is connected to the source of MOSFET Q3; the T2D winding of transformer T2 is connected to the other end of inductor L3A and one end of capacitors C32 and C33; the other end of capacitor C32 is connected to one end of resistor R37, one end of resistor R9 and one end of resistor R8; the other end of resistor R8 is grounded and the other ends of resistor R8, resistor R9 and capacitor C33 are all connected to capacitor C31; the other end of resistor R37 is connected to the ISEN pin of chip U1.
[0066] Capacitor C30 is also connected to the negative terminal of diode D2. The positive terminal of diode D2 is connected to the HS pin of chip U1 and is also connected to the negative terminal of diode D1, one end of capacitor C18, and one end of capacitor C7. The diode D1 is connected to the emitter of transistor Q5. The base of transistor Q5 is connected to the negative terminal of Zener diode ZD1 and one end of resistor R4. The collector of transistor Q5 is connected to the negative terminal of diode D6, the other end of resistor R4, and one end of capacitor C35. Transformer T2 is connected to the positive terminal of diode D6, the other end of capacitor C35, the other end of Zener diode ZD1, the other end of capacitor C7, and the other end of capacitor C18, and is connected to the VSEN pin of chip U1 through capacitor C6. Resistor R15 is connected in parallel with capacitor C6, and resistor R44 is connected between resistor R4 and capacitor C6. Windings T2A, T2B, and T2C of transformer T2 are all connected to the output synchronous rectifier circuit.
[0067] The output synchronous rectification circuit includes capacitors C9, C20, C21, C24, C25, C26, C27, C28, C29, C34, C36, C37, C38, C39, C40, C41, and C45; resistors R31, R47, R46, R63, R64, R65, R66, R69, R70, R71, R72, R73, and RS1; diodes D11 and D10; Zener diode ZD2; MOSFETs Q8 and Q9; transistor Q10; and chip U3. In this embodiment, chip U3 is an MPS6924.
[0068] The winding T2A of transformer T2 is connected to the positive terminal of diode D10, one end of capacitor C29, and the rectification terminal of Zener diode ZD2. The negative terminal of diode D10 is connected to the other end of capacitor C29 and to an external power supply. The VO+ terminal of transformer T2 is also connected to one end of resistor R46 and the collector of transistor Q10. The other end of resistor R46 is connected to the base of transistor Q10. The emitter of transistor Q10 is connected to the positive terminal of diode D11. The negative terminal of diode D1 is connected to an external power supply.
[0069] The VO+ terminal of transformer T2 is connected in series with resistors R47 and RS1 and then grounded. Capacitor C45 is connected in parallel with the series resistors R47 and RS1. Capacitors C24, C23, C26, C27, C28, and resistor R31 are connected in parallel with resistor R7. Resistors R47 and RS1 are also connected to the winding T2A of transformer T2.
[0070] The winding T2A of the transformer T2 is also connected to one end of the capacitor C38, the source of the MOSFET Q8, the gate of the MOSFET Q8, the second pin of the chip U3, the fifth pin of the chip U3, and one end of the resistor R69. The other end of the resistor R69 is connected to the third pin of the chip U3. The capacitor C34 is connected in parallel with the resistor R69. The other end of the capacitor C38 is connected to the sixth pin of the chip U3 through the series resistors R7 and R63. The resistors R70 and R71 are connected in parallel. The drain of the MOSFET Q8 is also connected to the winding T2B of the transformer T2 and the resistor R7. The base of the MOSFET Q8 is also connected to the eighth pin of the chip U3 through the resistor R65.
[0071] The winding T2A of the transformer T2 is also connected to one end of the capacitor C39, the source of the MOSFET Q9, and the gate of the MOSFET Q9. The gate of the MOSFET Q9 is also connected to the gate of the MOSFET Q8 and one end of the resistor R66. The other end of the resistor R66 is connected to the first pin of the chip U3. The other end of the capacitor C39 is connected to the fourth pin of the chip U3 through the series resistors R73 and R64. The resistors R72 and R73 are connected in parallel. The drain of the MOSFET Q9 is also connected to the winding T2C of the transformer T2 and the resistor R73.
[0072] The fifth pin of chip U3 is also connected to the seventh pin of chip U3 through resistor C36. The capacitor C37 is connected in parallel with capacitor C36. The seventh pin of chip U3 is also connected to an external power supply.
[0073] The output control circuit includes capacitors CX1, CX2, CX3, CX4, CX5, CX15, CX16, CX17, and CX18; resistors RX1, RX2, RX3, RX4, RX5, RX6, RX24, RX25, RX26, RX27, and RX28; a thermistor NX1; chips UX1, UX2, UX4, and UX5; an LED LD1; a Zener diode UX2; and a DIP switch SW1. In this embodiment, chip UX4 is model STC8H1K08T-33I-TSSOP20.
[0074] The first and third pins of chip UX1 are connected to the two ends of capacitor CX1. The first pin of chip UX1 is grounded, the second pin of chip UX1 is connected to an external power supply, capacitor CX2 is connected in parallel with capacitor CX1, and the third pin of chip UX1 is also connected to the VDD pin of chip UX4.
[0075] One end of the resistor RX3 is connected to the winding T2A of the transformer T2, and the other end of the resistor RX3 is connected to the VCS terminal of the chip UX4 through the series resistors RX4 and RX24. The capacitor CX4 is connected in parallel with the resistor RX4.
[0076] The first pin of the chip UX5 is connected to resistors RX4 and RX24. The second and third pins of the chip UX5 are grounded. The third pin of the chip UX5 is also connected to one end of capacitor CX18 and one end of capacitor CX15. The other end of capacitor CX18 is connected to resistor RX3. The other end of capacitor CX15 is connected to the VCS terminal of the chip UX4.
[0077] One end of the resistor RX26 is connected to the LLC resonant circuit, and the other end of the resistor RX26 is connected to one end of the resistor RX27 and the VOS pin of the chip UX4. The other end of the resistor RX27 is grounded, and the capacitor CX16 is connected in parallel with the resistor RX27.
[0078] One end of the thermistor NX1 is connected to the fifth pin of the chip UX5, and the other end of the thermistor NX1 is connected to the VTS pin of the chip UX4 and one end of the resistor RX28. The other end of the resistor RX28 is grounded. The resistor RX25 is connected in parallel with the thermistor NX1, and the capacitor CX17 is connected in parallel with the resistor RX28.
[0079] One end of resistor RX15 is connected to an external power supply, the other end of resistor RX15 is connected to the VAS pin of chip UX4 and one end of resistor RX6, the other end of resistor RX6 is grounded, and capacitor CX5 is connected in parallel with resistor RX6.
[0080] One end of resistor RX1 is connected to the LEDG pin of chip UX4, and the other end of resistor RX1 is connected to the positive terminal of light-emitting diode LD1, while the negative terminal of light-emitting diode LD1 is grounded; one end of resistor RX2 is connected to the VDD pin of chip UX4, and the other end of resistor RX2 is connected to the first pin of chip UX2, the second pin of chip UX2 is grounded, the third pin of chip UX2 is connected to the ninth pin of chip UX4, and capacitor CX3 is connected in parallel with chip UX2.
[0081] Pins 1, 2, 3, and 4 of DIP switch SW1 are grounded. Pin 5 of DIP switch SW1 is connected to pin SB4 of chip UX4. Pin 6 of DIP switch SW1 is connected to pin SB3 of chip UX4. Pin 7 of DIP switch SW1 is connected to pin SB2 of chip UX4. Pin 8 of DIP switch SW1 is connected to pin SB5 of chip UX4.
[0082] The output voltage feedback circuit includes optocoupler U2, resistors RX8 and RX, diodes DX1B and DX1A, resistors RX10, RX11, RX12, RX13, RX14, RX15, RS16, RX17, RS18, RX19, RX20, RX21, RX22, RX23, RX29, capacitors CX6, CX8, CS9, CX10, CX11, CX12, CX13, CX14, and operational amplifier UX6.
[0083] One end of resistor RX29 is connected to the VDD terminal of chip UX4, and the other end of resistor RX29 is grounded through capacitor CX6. The other end of resistor RX29 is connected to the VDA pin of chip UX5, the eighth pin of operational amplifier UX6, and one end of resistor RX8. The other end of resistor RX8 is connected to one end of resistor RX9, and the other end of resistor RX9 is connected to the anode of diode DX1B and the anode of diode DX1A.
[0084] The negative terminal of diode DX1B is connected to the seventh pin of the operational amplifier. The seventh pin of the operational amplifier UX6 is also connected to the sixth pin of the operational amplifier UX6 through resistor RX10 and capacitor CX8. The sixth pin of the operational amplifier UX6 is connected to one end of resistor RX17, one end of capacitor CX12, and one end of resistor RX19. The other end of capacitor CX12 is connected to one end of resistor RX18. The other ends of resistors RX17 and RX18 are connected to the VO+ terminal of transformer T2. The other end of resistor RX19 is grounded. The fifth pin of the operational amplifier UX6 is grounded through resistor RX15. Capacitor CX11 is connected in parallel with resistor RX15. The fifth pin of the operational amplifier UX6 is also connected to the VDD pin of chip UX4 through resistors RX14, RX21, and RX20 connected in series. Resistors RX21 and RX20 are also connected to the PWMA pin of chip UX4. Resistors RX14 and RX21 are grounded through capacitor CX13.
[0085] The positive terminal of diode DX1A is connected to the first pin of operational amplifier UX6. The first pin of operational amplifier UX6 is connected to the second pin of operational amplifier UX6 through resistor RX11 and capacitor CX9. The second pin of operational amplifier UX6 is grounded through resistor RX12. The third pin of operational amplifier UX6 is connected to the VDD pin of chip UX4 through resistors RX16, RX23, and RX22 connected in series. Resistors RX23 and RX22 are also connected to the PWMB pin of chip UX4. Resistors RX16 and RX23 are grounded through capacitor CX14.
[0086] The fourth pin of the operational amplifier UX6 is connected to the winding T2A of the transformer T2 through a series capacitor CX10 and a resistor RX13; one end of the optocoupler U2 is connected to both ends of the resistor RX8, and the other end of the optocoupler U2 is connected to both ends of the capacitor C17; the capacitor CX7 is connected in parallel with the resistor RX9.
[0087] In a preferred embodiment, a surge protection circuit is also included, which includes an impedance Z1, a thermistor N1, and a relay K1.
[0088] The impedance Z1 and capacitor C2 are connected in parallel across the common-mode inductor LF1. The relay K1 is connected between the other end of the common-mode inductor LF2 and one end of the magnetic core inductor L1. The relay K1 is also connected to one input terminal of the rectifier BD1 in the EMC electromagnetic filter circuit. The relay K1 is also connected to the LLC resonant circuit through resistor R7.
[0089] In this embodiment, chip UX4 is connected to chip UX1, diode DX1A, diode DX1B, capacitor CX9, resistor RX13, resistor RX16, capacitor CX10, capacitor CX11, resistor RX15, resistor RX14, capacitor CX13, resistor RX21, resistor RX29, resistor RX22, resistor RX23, resistor RX17, capacitor CX12, resistor RX19, capacitor CX5, resistor RX6, capacitor CX16, resistor RX27, capacitor CX1, capacitor CX14, resistor RX18, resistor RX5, resistor RX3, resistor RX2, resistor RX4, and capacitor CX4.
[0090] Chip UX4 is connected to resistors of different values. The DIP switch SW1 controls the grounding of pins SB4, SB3, SB2, and SB5 of chip UX4, thereby controlling the output voltage of the switching power supply circuit. When pin SB2 of chip UX4 is grounded, pin SB2 and PWMA output one operating voltage; when pin SB3 is grounded, pin SB3 and PWMB output another operating voltage; and when pin SB4 is grounded, pin SB4 and LEDG output yet another operating voltage. In a preferred embodiment, chip UX4 can output operating voltages of 36V, 42V, or 48V.
[0091] Meanwhile, the GATEL pin of chip U1 is connected to capacitor C33. Chip U1 detects the voltage level on capacitor C33. When the voltage of capacitor C33 exceeds the rated value, chip U1 disconnects from MOSFET Q2, MOSFET Q3, and transistor Q5, and stops supplying power to transformer T2, thereby achieving overcurrent protection and overpower protection.
[0092] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0093] In the description of this specification, the references to terms such as "preferred embodiment," "another embodiment," "other embodiment," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0094] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.
Claims
1. A smart, fast-conversion constant current and constant voltage switching power supply circuit, characterized in that: It includes an EMC electromagnetic filter circuit, a rectifier filter circuit, a PFC boost circuit, an LLC resonant circuit, an output synchronous rectifier circuit, an output control circuit, and an output voltage feedback circuit. The EMC electromagnetic filter circuit is connected to the power input terminal. One end of the rectifier filter circuit is connected to the EMC electromagnetic filter circuit, and the other end of the rectifier filter circuit is connected to one end of the PFC boost circuit. The other end of the PFC boost circuit is connected to the LLC resonant circuit, and the other end of the LLC resonant circuit is connected to the output synchronous rectifier circuit and the output voltage feedback circuit. The output synchronous rectifier circuit is also connected to the output control circuit, which is used to regulate the output voltage.
2. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 1, characterized in that: The EMC electromagnetic filter circuit includes a fuse F1, common mode inductors LF1 and LF2, a magnetic core inductor L1, capacitors C1, C2, C3, C4, and C8, and diodes D7 and D8; the rectifier filter circuit includes a rectifier bridge BD1 and capacitor C5. One end of fuse F1 is connected to the live wire, and the other end of fuse F1 is connected to one end of common mode inductor LF1. The other end of common mode inductor LF1 is connected to the neutral wire. Capacitor C1 is connected in parallel across the two ends of common mode inductor LF1. Capacitor C2, along with capacitors C3 and C4 connected in series, is connected in parallel between common mode inductor LF1 and common mode inductor LF2. The two ends of capacitor C2, one end of capacitor C3, and one end of capacitor C4 are respectively connected to common mode inductor LF1. The other ends of capacitor C3 and capacitor C4 are grounded through capacitor C8. One end of the common-mode inductor LF2 is connected to the positive terminal of diode D7 and one input terminal of rectifier BD1. The other end of the common-mode inductor LF2 is connected to one end of the core inductor L1. The other end of the core inductor L1 is connected to the positive terminal of diode D8 and the other input terminal of rectifier BD1. The negative terminal of diode D7 is connected to the negative terminal of diode D8. The output terminal of rectifier BD1 is connected to the PFC boost circuit through capacitor C5.
3. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 2, characterized in that: The PFC boost circuit includes chip U1, resistors R1, R2, R5, R10, R11, R12, R13, R14, R19, R20, R26, R29, R32, R33, R34, R38, R53, R54, R55, inductors L2A, L2B, and L4, switch S1, capacitors C10, C11, C12, C13, C14, C22, C23, C47, and C48, diodes D3, D9, and D12, transistor Q4, MOSFET Q1A, and MOSFET Q1; One end of resistor R1 is connected to the cathodes of diodes D7 and D8. The other end of resistor R1 is connected in series with resistors R2, R14, and R5. One end of resistor R5 is connected to one end of capacitor C11 and one end of resistor R26. The other ends of capacitor C11 and resistor R26 are grounded. One end of resistor R5, one end of capacitor C11, and one end of resistor R26 are also connected to the LNS pin of chip U1. The two output terminals of the rectifier BD1 are connected through capacitor C5. Capacitor C5 is also grounded through resistor R32. Resistor E33 is connected in parallel with resistor R32. Capacitor C5 is also grounded through series resistor R29 and capacitor C12. Resistor R32 is connected in parallel with series resistor R29 and capacitor C12. One end of resistor R29 and one end of capacitor C12 are connected to the CS pin of chip U1. One output terminal of rectifier BD1 is also connected to one end of inductor L2A. The other end of inductor L2A is connected to ground in series with inductor L4, diode D9, and capacitor C23. Diode D9 is also connected to LLC resonant circuit. Diode D9 is also connected in series with resistors R19, R20, and R45. One end of resistor R45 is grounded through parallel resistors R34, R38, and capacitor C22. Resistor R45 and capacitor C22 are also connected to the FBB pin of chip U1. Resistors R19, R20, R45, and capacitor C23 are connected in parallel. The capacitors C10, C13, and C14 are connected in parallel with the capacitor C23; the inductor L2B is connected in parallel with the inductor L2A; and the diode D12 is connected in parallel with the inductor L2A, the inductor L4, and the diode D9. Inductor L2A is also connected to the drain of MOSFET Q1A, one end of resistor R10, and one end of capacitor C48. The other end of resistor R10 is connected to the HV pin of chip U1. The other end of capacitor C48 is connected to the source of MOSFET Q1A through resistor R55. The source of MOSFET Q1A is grounded. Resistor R54 and capacitor C47 are connected in parallel with resistor R55. The gate of MOSFET Q1A is connected to one end of resistor R12. The other end of resistor R12 is connected to the emitter of transistor Q4, one end of resistor R13, and one end of resistor R11. The collector of transistor Q4 is connected to the source of MOSFET Q1A. The base of transistor Q4 is connected to the anode of diode D3 and resistor R53. The cathode of diode D3 is connected to resistor R10. Resistor R53 is connected to the GATEB pin of chip U1. The other end of resistor R13 is grounded. The other end of R11 is connected to the gate of MOSFET Q1. The source of MOSFET Q1 is grounded. The drain of MOSFET Q1 is connected to inductor L2A.
4. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 3, characterized in that: The LLC resonant circuit includes resistors R3, R4, R7, R15, R16, R17, R22, R23, R24, R25, R44, and R37; capacitors C6, C7, R8, C17, C18, C18, C30, C31, C32, C33, C35, C49; inductors L3A and L3B; diodes D1, D2, D4, and D5; Zener diode ZD1; transistor Q5; MOSFET Q2 and Q3; diode D6; and transformer T2. One end of resistor R23 is connected to the GATEH pin of chip U1, the other end of resistor R23 is connected to one end of resistor R22, the other end of resistor R22 is connected to one end of resistor R16 and the gate of MOSFET Q2, and diode D4 is connected in parallel with resistor R22. The drain of MOSFET Q2 is connected to the cathode of diode D9, and the source of MOSFET Q2 is connected to the drain of MOSFET Q3. The source of MOSFET Q2 is connected to the ISEN pin of chip U1 through capacitor C31. The gate of MOSFET Q3 is connected in series with resistors R25 and R24 and the GATEL pin of chip U1. The gate of MOSFET Q3 is also connected to one end of resistor R17, and the other end of resistor R17 is connected to capacitor C31. The source of MOSFET Q2 is also connected to one end of inductor L3A and capacitor C4. One end of 9 is connected, and the other end of capacitor C49 is connected to the source of MOSFET Q3; the T2D winding of transformer T2 is connected to the other end of inductor L3A and one end of capacitors C32 and C33; the other end of capacitor C32 is connected to one end of resistor R37, one end of resistor R9 and one end of resistor R8; the other end of resistor R8 is grounded, and the other ends of resistor R8, resistor R9 and capacitor C33 are all connected to capacitor C31; the other end of resistor R37 is connected to the ISEN pin of chip U1. Capacitor C30 is also connected to the negative terminal of diode D2. The positive terminal of diode D2 is connected to the HS pin of chip U1 and is also connected to the negative terminal of diode D1, one end of capacitor C18, and one end of capacitor C7. The diode D1 is connected to the emitter of transistor Q5. The base of transistor Q5 is connected to the negative terminal of Zener diode ZD1 and one end of resistor R4. The collector of transistor Q5 is connected to the negative terminal of diode D6, the other end of resistor R4, and one end of capacitor C35. Transformer T2 is connected to the positive terminal of diode D6, the other end of capacitor C35, the other end of Zener diode ZD1, the other end of capacitor C7, and the other end of capacitor C18, and is connected to the VSEN pin of chip U1 through capacitor C6. Resistor R15 is connected in parallel with capacitor C6, and resistor R44 is connected between resistor R4 and capacitor C6. Windings T2A, T2B, and T2C of transformer T2 are all connected to the output synchronous rectifier circuit.
5. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 1, characterized in that: The output synchronous rectification circuit includes capacitors C9, C20, C21, C24, C25, C26, C27, C28, C29, C34, C36, C37, C38, C39, C40, C41, and C45; resistors R31, R47, R46, R63, R64, R65, R66, R69, R70, R71, R72, R73, and RS1; diodes D11 and D10; Zener diode ZD2; MOSFETs Q8 and Q9; transistor Q10; and chip U3. The winding T2A of transformer T2 is connected to the positive terminal of diode D10, one end of capacitor C29, and the rectifier terminal of Zener diode ZD2. The negative terminal of diode D10 is connected to the other end of capacitor C29 and to an external power supply. The VO+ terminal of transformer T2 is also connected to one end of resistor R46 and the collector of transistor Q10. The other end of resistor R46 is connected to the base of transistor Q10. The emitter of transistor Q10 is connected to the positive terminal of diode D11. The negative terminal of diode D1 is connected to an external power supply. The VO+ terminal of transformer T2 is connected to ground in series with resistors R47 and RS1. Capacitor C45 is connected in parallel with resistors R47 and RS1. Capacitors C24, C23, C26, C27, C28, and resistor R31 are connected in parallel with resistor R7. Resistors R47 and RS1 are also connected to winding T2A of transformer T2. The winding T2A of the transformer T2 is also connected to one end of the capacitor C38, the source of the MOSFET Q8, the gate of the MOSFET Q8, the second pin of the chip U3, the fifth pin of the chip U3, and one end of the resistor R69. The other end of the resistor R69 is connected to the third pin of the chip U3. The capacitor C34 is connected in parallel with the resistor R69. The other end of the capacitor C38 is connected to the sixth pin of the chip U3 through the series resistors R7 and R63. The resistors R70 and R71 are connected in parallel. The drain of the MOSFET Q8 is also connected to the winding T2B of the transformer T2 and the resistor R7. The base of the MOSFET Q8 is also connected to the eighth pin of the chip U3 through the resistor R65. The winding T2A of the transformer T2 is also connected to one end of the capacitor C39, the source of the MOSFET Q9, and the gate of the MOSFET Q9. The gate of the MOSFET Q9 is also connected to the gate of the MOSFET Q8 and one end of the resistor R66. The other end of the resistor R66 is connected to the first pin of the chip U3. The other end of the capacitor C39 is connected to the fourth pin of the chip U3 through the series resistors R73 and R64. The resistors R72 and R73 are connected in parallel. The drain of the MOSFET Q9 is also connected to the winding T2C of the transformer T2 and the resistor R73. The fifth pin of chip U3 is also connected to the seventh pin of chip U3 through resistor C36. The capacitor C37 is connected in parallel with capacitor C36. The seventh pin of chip U3 is also connected to an external power supply.
6. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 3, characterized in that: The output control circuit includes capacitors CX1, CX2, CX3, CX4, CX5, CX15, CX16, CX17, and CX18; resistors RX1, RX2, RX3, RX4, RX5, RX6, RX24, RX25, RX26, RX27, and RX28; a thermistor NX1; chips UX1, UX2, UX4, and UX5; an LED LD1; a Zener diode UX2; and a DIP switch SW1. The first and third pins of chip UX1 are connected to the two ends of capacitor CX1. The first pin of chip UX1 is grounded. The second pin of chip UX1 is connected to an external power supply. Capacitor CX2 is connected in parallel with capacitor CX1. The third pin of chip UX1 is also connected to the VDD pin of chip UX4. One end of the resistor RX3 is connected to the winding T2A of the transformer T2, and the other end of the resistor RX3 is connected to the VCS terminal of the chip UX4 through the series resistors RX4 and RX24. The capacitor CX4 is connected in parallel with the resistor RX4. The first pin of the chip UX5 is connected to resistors RX4 and RX24. The second and third pins of the chip UX5 are grounded. The third pin of the chip UX5 is also connected to one end of capacitor CX18 and one end of capacitor CX15. The other end of capacitor CX18 is connected to resistor RX3. The other end of capacitor CX15 is connected to the VCS terminal of the chip UX4. One end of the resistor RX26 is connected to the LLC resonant circuit, and the other end of the resistor RX26 is connected to one end of the resistor RX27 and the VOS pin of the chip UX4. The other end of the resistor RX27 is grounded, and the capacitor CX16 is connected in parallel with the resistor RX27. One end of the thermistor NX1 is connected to the fifth pin of the chip UX5, and the other end of the thermistor NX1 is connected to the VTS pin of the chip UX4 and one end of the resistor RX28. The other end of the resistor RX28 is grounded. The resistor RX25 is connected in parallel with the thermistor NX1, and the capacitor CX17 is connected in parallel with the resistor RX28. One end of the resistor RX15 is connected to an external power supply, the other end of the resistor RX15 is connected to the VAS pin of the chip UX4 and one end of the resistor RX6, the other end of the resistor RX6 is grounded, and the capacitor CX5 is connected in parallel with the resistor RX6. One end of resistor RX1 is connected to the LEDG pin of chip UX4, and the other end of resistor RX1 is connected to the positive terminal of light-emitting diode LD1, and the negative terminal of light-emitting diode LD1 is grounded; one end of resistor RX2 is connected to the VDD pin of chip UX4, and the other end of resistor RX2 is connected to the first pin of chip UX2, the second pin of chip UX2 is grounded, the third pin of chip UX2 is connected to the ninth pin of chip UX4, and capacitor CX3 is connected in parallel with chip UX2; Pins 1, 2, 3, and 4 of DIP switch SW1 are grounded. Pin 5 of DIP switch SW1 is connected to pin SB4 of chip UX4. Pin 6 of DIP switch SW1 is connected to pin SB3 of chip UX4. Pin 7 of DIP switch SW1 is connected to pin SB2 of chip UX4. Pin 8 of DIP switch SW1 is connected to pin SB5 of chip UX4.
7. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 6, characterized in that: The output voltage feedback circuit includes optocoupler U2, resistor RX8, resistor RX, diode DX1B, diode DX1A, resistor RX10, resistor RX11, resistor RX12, resistor RX13, resistor RX14, resistor RX15, resistor RS16, resistor RX17, resistor RS18, resistor RX19, resistor RX20, resistor RX21, resistor RX22, resistor RX23, resistor RX29, capacitor CX6, capacitor CX8, capacitor CS9, capacitor CX10, capacitor CX11, capacitor CX12, capacitor CX13, capacitor CX14, and operational amplifier UX6; One end of resistor RX29 is connected to the VDD terminal of chip UX4, and the other end of resistor RX29 is grounded through capacitor CX6. The other end of resistor RX29 is also connected to the VDA pin of chip UX5, the eighth pin of operational amplifier UX6, and one end of resistor RX8. The other end of resistor RX8 is connected to one end of resistor RX9, and the other end of resistor RX9 is connected to the anodes of diodes DX1B and DX1A. The negative terminal of diode DX1B is connected to the seventh pin of operational amplifier UX6. The seventh pin of operational amplifier UX6 is also connected to the sixth pin of operational amplifier UX6 through resistor RX10 and capacitor CX8. The sixth pin of operational amplifier UX6 is connected to one end of resistor RX17, one end of capacitor CX12, and one end of resistor RX19. The other end of capacitor CX12 is connected to one end of resistor RX18. The other ends of resistor RX17 and resistor RX18 are connected to the VO+ terminal of transformer T2. The other end of resistor RX19 is grounded. The fifth pin of operational amplifier UX6 is grounded through resistor RX15. Capacitor CX11 is connected in parallel with resistor RX15. The fifth pin of operational amplifier UX6 is also connected to the VDD pin of chip UX4 through resistors RX14, RX21, and RX20 connected in series. Resistors RX21 and RX20 are also connected to the PWMA pin of chip UX4. Resistors RX14 and RX21 are grounded through capacitor CX13. The positive terminal of diode DX1A is connected to the first pin of operational amplifier UX6. The first pin of operational amplifier UX6 is connected to the second pin of operational amplifier UX6 through resistor RX11 and capacitor CX9. The second pin of operational amplifier UX6 is grounded through resistor RX12. The third pin of operational amplifier UX6 is connected to the VDD pin of chip UX4 through resistors RX16, RX23, and RX22 connected in series. Resistors RX23 and RX22 are also connected to the PWMB pin of chip UX4. Resistors RX16 and RX23 are grounded through capacitor CX14. The fourth pin of the operational amplifier UX6 is connected to the winding T2A of the transformer T2 through a series capacitor CX10 and a resistor RX13; one end of the optocoupler U2 is connected to both ends of the resistor RX8, and the other end of the optocoupler U2 is connected to both ends of the capacitor C17; the capacitor CX7 is connected in parallel with the resistor RX9.
8. The intelligent fast-conversion constant current constant voltage switching power supply circuit according to claim 2, characterized in that: It also includes a surge protection circuit, which consists of an impedance Z1, a thermistor N1, and a relay K1. The impedance Z1 and capacitor C2 are connected in parallel across the common-mode inductor LF1. The relay K1 is connected between the other end of the common-mode inductor LF2 and one end of the magnetic core inductor L1. The relay K1 is also connected to one input terminal of the rectifier BD1 in the EMC electromagnetic filter circuit. The relay K1 is also connected to the LLC resonant circuit through resistor R7.