CN211018675U - Flyback AC-DC constant current power supply box - Google Patents
Flyback AC-DC constant current power supply box Download PDFInfo
- Publication number
- CN211018675U CN211018675U CN202020121489.9U CN202020121489U CN211018675U CN 211018675 U CN211018675 U CN 211018675U CN 202020121489 U CN202020121489 U CN 202020121489U CN 211018675 U CN211018675 U CN 211018675U
- Authority
- CN
- China
- Prior art keywords
- circuit
- pin
- output
- flyback
- power supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model discloses a flyback AC-DC constant current power supply case, include: the pre-stage filter rectification circuit is used for carrying out filter rectification on the alternating current and outputting the alternating current to the flyback transformer; a flyback transformer for stepping down; the switch control circuit is used for controlling the on-off of the input current of the flyback transformer; the feedback detection circuit is used for detecting the output voltage of the flyback transformer and feeding back the output voltage to the control chip; the post-stage filter circuit is used for filtering the output current of the flyback transformer; a shunt output circuit for shunting the modulated current to a load for output; the utility model is used for change the commercial power into 12V2A direct current of multiplexed output, and can automatically adjust the total output power according to the load, improve the frequency and the efficiency of the switching power supply; a piezoresistor is arranged in the pre-stage filter rectifying circuit to perform overvoltage protection on the circuit, so that the failure rate of equipment is reduced, and the service life of the equipment is prolonged.
Description
Technical Field
The utility model relates to a switching power supply field, concretely relates to flyback AC-DC constant current power supply case.
Background
The switch power supply has the outstanding advantages of small energy consumption, high efficiency, wide voltage stabilizing range, small volume, light weight and the like, and is widely applied to electronic circuits such as communication equipment, numerical control devices, instruments, video equipment, household appliances and the like. The typical structure of the switching power supply comprises a series switching power supply structure, a parallel switching power supply structure, a forward switching power supply structure, a flyback switching power supply structure, a half-bridge switching power supply structure and a full-bridge switching power supply structure, wherein the flyback switching power supply circuit is simple, the output voltage can be higher than the input voltage and lower than the input voltage, and the flyback switching power supply is generally suitable for the switching power supply with the output power of less than 200W. The existing switching power supply generally adopts a voltage type pulse width modulator, but the frequency response of the voltage type pulse width modulator is slow, and the voltage regulation rate and the load regulation rate are low, so that the efficiency of the switching power supply is low.
Disclosure of Invention
In view of the above, the utility model provides a flyback AC-DC constant current power supply box for convert commercial power into 12V2A direct current of multiplexed output.
A flyback AC-DC constant current power supply box comprises:
the pre-stage filter rectification circuit is used for carrying out filter rectification on the alternating current and outputting the alternating current to the flyback transformer;
a flyback transformer for stepping down;
the switch control circuit is used for controlling the on-off of the input current of the flyback transformer;
the feedback detection circuit is used for detecting the output voltage of the flyback transformer and feeding back the output voltage to the control chip;
the post-stage filter circuit is used for filtering the output current of the flyback transformer;
and the shunt output circuit is used for shunting the modulated current to the load for output.
Preferably, the pre-stage filter rectification circuit comprises an EMI filter circuit and a rectifier bridge circuit;
the EMI filter circuit is used for circuit noise reduction and interference suppression.
Preferably, the EMI filter circuit includes a first common mode choke L1, an across line capacitor CX1, an across line capacitor CX2, a bypass capacitor CY1, and a bypass capacitor CY 2;
a first pin and a third pin of the first common mode choke L1 are respectively connected with a live wire and a zero wire of an external power supply, and a second pin and a fourth pin are respectively connected with two input ends of the rectifier bridge circuit;
two ends of the over-line capacitor CX1 are respectively connected with the first pin and the third pin of the first common mode choke L1;
two ends of the over-line capacitor CX2 are respectively connected with the second pin and the fourth pin of the first common mode choke L1;
the bypass capacitor CY1 and the bypass capacitor CY2 are connected in series and then connected in parallel with the flying capacitor CX 2.
Preferably, the EMI filter circuit further includes a voltage dependent resistor VR1, and the voltage dependent resistor VR1 is connected in parallel with the flying capacitor CX 1.
Preferably, the flyback transformer comprises a primary coil, a first secondary coil and a second secondary coil;
the input end of the primary coil is connected with the output end of the preceding stage rectification filter circuit, and the output end of the primary coil is connected with the signal output end of the switch control circuit;
the first secondary coil is connected with the post-stage filter circuit;
the second secondary coil is connected with the feedback detection circuit.
Preferably, the switch control circuit includes:
the control chip is used for comparing the feedback output voltage with the reference voltage, an MOS (metal oxide semiconductor) tube is arranged in the control chip, and an on-off control signal is output to the flyback transformer according to a comparison result;
the chip protection circuit is used for transmitting working current to the control chip and protecting the control chip when the voltage is unstable;
and the voltage spike absorption circuit is used for absorbing voltage spikes when the primary coil of the flyback transformer is disconnected.
Preferably, the voltage spike absorption circuit comprises a diode D7, a resistor R3, a resistor R2 and a capacitor C4;
the anode of the diode D7 is connected between the output end of the primary coil and the Train pin of the control chip, and the cathode of the diode D7 is connected with the first pin of the resistor R3;
the resistor R2 and the capacitor C4 are connected in parallel between the second pin of the resistor R3 and the input end of the primary coil.
Preferably, the chip protection circuit includes a resistor R5 and a resistor R6 connected in series;
the first pin of the resistor R6 is connected with the output end of the pre-stage filter rectifying circuit, the second pin of the resistor R6 is connected with the first pin of the resistor R5, and the second pin of the resistor R5 is connected with the VDD pin of the control chip.
Preferably, the post-stage filter circuit comprises a synchronous rectification chip D4 and a low-pass filter circuit;
the anode of the synchronous rectification chip D4 is connected with the anode of the first secondary coil, the cathode of the synchronous rectification chip D4 is connected with the input end of the low-pass filter circuit, and the output end of the low-pass filter circuit is grounded;
the low-pass filter circuit comprises an electrolytic capacitor C8, an electrolytic capacitor C9 and a resistor R10 which are arranged in parallel.
Preferably, the shunt output circuit comprises a plurality of output port circuits arranged in parallel;
the output port circuit comprises a terminal base, a fuse and a second common mode choke coil;
the output end of the post-stage filter circuit is connected with the second port of the terminal base, one end of the fuse is connected with the second port of the terminal base, the other end of the fuse is connected with the second pin of the second common mode choke coil, and the first port of the terminal base is connected with the fourth pin of the second common mode choke coil;
the first leg and the third leg of the second common mode choke are connected to a load.
The utility model has the advantages that: a flyback AC-DC constant current power supply box comprises: the pre-stage filter rectification circuit is used for carrying out filter rectification on the alternating current and outputting the alternating current to the flyback transformer; a flyback transformer for stepping down; the switch control circuit is used for controlling the on-off of the input current of the flyback transformer; the feedback detection circuit is used for detecting the output voltage of the flyback transformer and feeding back the output voltage to the control chip; the post-stage filter circuit is used for filtering the output current of the flyback transformer; a shunt output circuit for shunting the modulated current to a load for output; the utility model can automatically adjust the total output power according to the load, and improve the frequency and efficiency of the switch power supply; a piezoresistor is arranged in the pre-stage filter rectifying circuit to perform overvoltage protection on the circuit, so that the failure rate of equipment is reduced, and the service life of the equipment is prolonged.
Drawings
The flyback AC-DC constant current power supply box of the present invention will be further described with reference to the accompanying drawings.
Fig. 1 is a schematic circuit diagram of a flyback AC-DC constant current power supply box of the present invention.
Fig. 2 is a schematic diagram of an EMI filter circuit.
Fig. 3 is a schematic diagram of a rectifier bridge circuit.
Fig. 4 is a schematic diagram of a switch control circuit and a feedback detection circuit.
Fig. 5 is a schematic diagram of a post-stage filter circuit.
Fig. 6 is an output port circuit schematic.
In the figure:
100-a front-stage filter rectifying circuit, 101-an EMI filter circuit, 102-a rectifier bridge circuit, 200-a flyback transformer, 201-a primary coil, 202-a first secondary coil, 203-a second secondary coil, 300-a switch control circuit, 301-a control chip, 302-a chip protection circuit, 303-a voltage spike absorption circuit, 400-a feedback detection circuit, 500-a rear-stage filter circuit, 501-a low-pass filter circuit, 600-a shunt output circuit, 1-an output port circuit, 11-a terminal base, 12-a fuse and 13-a second common mode choke coil.
Detailed Description
The flyback AC-DC constant current power supply box of the present invention will be further described with reference to fig. 1 to 4.
A flyback AC-DC constant current power supply box comprises:
a pre-stage filter rectification circuit 100 for performing filter rectification on the ac power and outputting the ac power to the flyback transformer 200;
a flyback transformer 200 for voltage reduction;
the switching control circuit 300 is used for controlling the on-off of the input current of the flyback transformer 200;
a feedback detection circuit 400 for detecting an output voltage of the flyback transformer 200 and feeding back the output voltage to the control chip 301;
a post-stage filter circuit 500 for filtering the output current of the flyback transformer 200;
and a shunt output circuit 600 for shunting the modulated current to the load for output.
In this embodiment, the pre-stage filter and rectifier circuit 100 includes an EMI filter circuit 101 and a rectifier bridge circuit 102;
the EMI filter circuit 101 is used for circuit noise reduction and interference suppression;
the input end of the EMI filter circuit 101 is connected to the mains supply, and the output end of the EMI filter circuit 101 is connected to the input end of the rectifier bridge circuit 102.
In this embodiment, the EMI filter circuit 101 includes a first common mode choke L1, an inter-line capacitor CX1, an inter-line capacitor CX2, a bypass capacitor CY1, and a bypass capacitor CY 2;
a first pin and a third pin of the first common mode choke L1 are respectively connected with a live wire and a zero wire of an external power supply, and a second pin and a fourth pin are respectively connected with two input ends of the rectifier bridge circuit 102;
two ends of the over-line capacitor CX1 are respectively connected with the first pin and the third pin of the first common mode choke L1;
two ends of the over-line capacitor CX2 are respectively connected with the second pin and the fourth pin of the first common mode choke L1;
the bypass capacitor CY1 and the bypass capacitor CY2 are connected in series and then connected in parallel with the over-line capacitor CX2, and a grounding point is arranged between the bypass capacitor CY1 and the bypass capacitor CY 2.
In this embodiment, the EMI filter circuit 101 further includes a voltage dependent resistor VR1, where the voltage dependent resistor VR1 is connected in parallel with the flying capacitor CX 1;
the voltage-limiting circuit further comprises current-limiting resistors R L1 and R L2, the current-limiting resistors R L1 and R L2 are connected in series and then are connected in parallel with the voltage-sensitive resistor VR1 and the over-line capacitor CX1 to be arranged between the live line and the zero line, and the resistance values of the current-limiting resistors R L1 and R L2 are the same.
The fuse F1 is further included, one end of the fuse F1 is connected with the zero line, and the other end of the fuse F1 is connected with the voltage dependent resistor VR1, the over-line capacitor CX1, the resistor R L and the third pin of the first common mode choke L1.
In this embodiment, the flyback transformer 200 includes a primary coil 201, a first secondary coil 202, and a second secondary coil 203;
the input end of the primary coil 201 is connected with the output end of the preceding stage rectification filter circuit, and the output end of the primary coil 201 is connected with the signal output end of the switch control circuit 300;
the first secondary winding 202 is connected to the post-filter circuit 500 for step-down output;
the second secondary winding 203 is connected to the feedback detection circuit 400 for providing a feedback voltage signal to the switch control circuit 300.
In this embodiment, the switch control circuit 300 includes:
the control chip 301 is used for comparing the feedback output voltage with a reference voltage, and meanwhile, an MOS transistor is arranged in the control chip 301 and outputs an on-off control signal to the flyback transformer 200 according to a comparison result;
the chip protection circuit 302 is used for transmitting working current to the control chip 301 and protecting the control chip 301 when the voltage is unstable, the input end of the chip protection circuit 302 is connected with the output end of the rectifier bridge circuit 102, and the output end of the chip protection circuit 302 is connected with a VDD pin of the control chip 301;
a voltage spike absorption circuit 303; for absorbing voltage spikes when the primary coil 201 of the flyback transformer 200 is turned off.
In this embodiment, the voltage spike absorption circuit 303 includes a diode D7, a resistor R3, a resistor R2, and a capacitor C4;
the anode of the diode D7 is connected between the output end of the primary coil 201 and the Train pin of the control chip 301, and the cathode of the diode D7 is connected with the first pin of the resistor R3;
the resistor R2 and the capacitor C4 are connected in parallel between the second leg of the resistor R3 and the input terminal of the primary coil 201.
In this embodiment, the chip protection circuit 302 includes a resistor R5 and a resistor R6 connected in series;
the first pin of the resistor R6 is connected with the output end of the pre-stage filter rectifying circuit 100, the second pin of the resistor R6 is connected with the first pin of the resistor R5, and the second pin of the resistor R5 is connected with the VDD pin of the control chip 301.
In this embodiment, the post-stage filter circuit 500 includes a synchronous rectification chip D4 and a low-pass filter circuit 501;
the anode of the synchronous rectification chip D4 is connected with the anode of the first secondary coil 202, the cathode of the synchronous rectification chip D4 is connected with the input end of the low-pass filter circuit 501, and the output end of the low-pass filter circuit 501 is grounded;
the low-pass filter circuit 501 includes an electrolytic capacitor C8, an electrolytic capacitor C9, and a resistor R10, which are arranged in parallel.
In this embodiment, the shunt output circuit 600 includes 8 output port circuits 1 arranged in parallel;
the output port circuit 1 includes a terminal block 11, a fuse 12, and a second common mode choke coil 13;
the fuse 12 is a self-recovery fuse;
the second port of the terminal block 11 is connected to the output end of the post-stage filter circuit 500 and one end of the fuse 12, the other end of the fuse 12 is connected to the second pin of the second common mode choke coil 13, and the first port of the terminal block 11 is connected to the fourth pin of the second common mode choke coil 13;
the first leg and the third leg of the second common mode choke 13 are connected to the load, while the third leg is set to ground.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications can be made without departing from the principle of the present invention, and these modifications should also be regarded as the protection scope of the present invention.
Claims (10)
1. A flyback AC-DC constant current power supply box is characterized by comprising:
the pre-stage filter rectification circuit is used for carrying out filter rectification on the alternating current and outputting the alternating current to the flyback transformer;
a flyback transformer for stepping down;
the switch control circuit is used for controlling the on-off of the input current of the flyback transformer;
the feedback detection circuit is used for detecting the output voltage of the flyback transformer and feeding back the output voltage to the control chip;
the post-stage filter circuit is used for filtering the output current of the flyback transformer;
and the shunt output circuit is used for shunting the modulated current to the load for output.
2. The flyback AC-DC constant current power supply box of claim 1, wherein the pre-filter rectification circuit comprises an EMI filter circuit and a rectifier bridge circuit;
the EMI filter circuit is used for circuit noise reduction and interference suppression.
3. The flyback AC-DC constant current power supply box of claim 2, wherein the EMI filter circuit includes a first common mode choke L1, an across-line capacitance CX1, an across-line capacitance CX2, a bypass capacitance CY1, and a bypass capacitance CY 2;
a first pin and a third pin of the first common mode choke L1 are respectively connected with a live wire and a zero wire of an external power supply, and a second pin and a fourth pin are respectively connected with two input ends of the rectifier bridge circuit;
two ends of the over-line capacitor CX1 are respectively connected with the first pin and the third pin of the first common mode choke L1;
two ends of the over-line capacitor CX2 are respectively connected with the second pin and the fourth pin of the first common mode choke L1;
the bypass capacitor CY1 and the bypass capacitor CY2 are connected in series and then connected in parallel with the over-line capacitor CX2, and a grounding point is arranged between the bypass capacitor CY1 and the bypass capacitor CY 2.
4. The flyback AC-DC constant current power supply box of claim 3, wherein the EMI filter circuit further comprises a varistor VR1, the varistor VR1 being disposed in parallel with the flying capacitor CX 1.
5. The flyback AC-DC constant current power supply case of claim 1, wherein the flyback transformer includes a primary coil, a first secondary coil, a second secondary coil;
the input end of the primary coil is connected with the output end of the preceding stage rectification filter circuit, and the output end of the primary coil is connected with the signal output end of the switch control circuit;
the first secondary coil is connected with the post-stage filter circuit and used for voltage reduction output;
the second secondary coil is connected with the feedback detection circuit and used for providing a feedback voltage signal for the switch control circuit.
6. The flyback AC-DC constant current power supply box of claim 5, wherein the switch control circuit comprises:
the control chip is used for comparing the feedback output voltage with the reference voltage, an MOS (metal oxide semiconductor) tube is arranged in the control chip, and an on-off control signal is output to the flyback transformer according to a comparison result;
the chip protection circuit is used for transmitting working current to the control chip and protecting the control chip when the voltage is unstable;
and the voltage spike absorption circuit is used for absorbing voltage spikes when the primary coil of the flyback transformer is disconnected.
7. The flyback AC-DC constant current power supply box of claim 6, wherein the voltage spike absorption circuit comprises a diode D7, a resistor R3, a resistor R2, and a capacitor C4;
the anode of the diode D7 is connected between the output end of the primary coil and the Train pin of the control chip, and the cathode of the diode D7 is connected with the first pin of the resistor R3;
the resistor R2 and the capacitor C4 are connected in parallel between the second pin of the resistor R3 and the input end of the primary coil.
8. The flyback AC-DC constant current power supply box of claim 6, wherein the chip protection circuit comprises a resistor R5 and a resistor R6 connected in series;
the first pin of the resistor R6 is connected with the output end of the pre-stage filter rectifying circuit, the second pin of the resistor R6 is connected with the first pin of the resistor R5, and the second pin of the resistor R5 is connected with the VDD pin of the control chip.
9. The flyback AC-DC constant current power supply box of claim 5, wherein the post-stage filter circuit comprises a synchronous rectification chip D4 and a low pass filter circuit;
the anode of the synchronous rectification chip D4 is connected with the anode of the first secondary coil, the cathode of the synchronous rectification chip D4 is connected with the input end of the low-pass filter circuit, and the output end of the low-pass filter circuit is grounded;
the low-pass filter circuit comprises an electrolytic capacitor C8, an electrolytic capacitor C9 and a resistor R10 which are arranged in parallel.
10. The flyback AC-DC constant current power supply case of claim 9, wherein the shunt output circuit comprises a plurality of output port circuits arranged in parallel;
the output port circuit comprises a terminal base, a fuse and a second common mode choke coil;
the output end of the post-stage filter circuit is connected with the second port of the terminal base, one end of the fuse is connected with the second port of the terminal base, the other end of the fuse is connected with the second pin of the second common mode choke coil, and the first port of the terminal base is connected with the fourth pin of the second common mode choke coil;
the first leg and the third leg of the second common mode choke are connected to a load.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020121489.9U CN211018675U (en) | 2020-01-19 | 2020-01-19 | Flyback AC-DC constant current power supply box |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020121489.9U CN211018675U (en) | 2020-01-19 | 2020-01-19 | Flyback AC-DC constant current power supply box |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211018675U true CN211018675U (en) | 2020-07-14 |
Family
ID=71479796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020121489.9U Active CN211018675U (en) | 2020-01-19 | 2020-01-19 | Flyback AC-DC constant current power supply box |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211018675U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117674612A (en) * | 2024-02-01 | 2024-03-08 | 深圳市力生美半导体股份有限公司 | Power supply circuit and switching power supply |
-
2020
- 2020-01-19 CN CN202020121489.9U patent/CN211018675U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117674612A (en) * | 2024-02-01 | 2024-03-08 | 深圳市力生美半导体股份有限公司 | Power supply circuit and switching power supply |
| CN117674612B (en) * | 2024-02-01 | 2024-05-31 | 深圳市力生美半导体股份有限公司 | Power supply circuit and switching power supply |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8929107B2 (en) | Active surge protection in a power supply | |
| KR100904299B1 (en) | Power factor compensation circuit and driving metod thereof | |
| CN102026448A (en) | LED power circuit | |
| CN211018675U (en) | Flyback AC-DC constant current power supply box | |
| CN207782395U (en) | A kind of thermal-shutdown circuit and electronic equipment | |
| CN114340077A (en) | LED dimming circuit, dimming LED lamp and LED dimming method based on LED dimming circuit | |
| CN212305135U (en) | Power protection circuit, power supply and electronic equipment | |
| CN101064429A (en) | Burst current suppressing circuit and power supply equipment using the same | |
| CN216252552U (en) | Switching power supply circuit | |
| CN206834987U (en) | A kind of control system of the flyback transformer based on Switching Power Supply | |
| CN214205901U (en) | Primary side feedback LED drive circuit and power supply for reducing output voltage no-load value | |
| CN213402543U (en) | Safety protection power supply circuit | |
| CN111464054A (en) | Direct current switch power supply | |
| CN108667320B (en) | Switch power supply with overcurrent protection and self-reset | |
| CN215817920U (en) | Power supply circuit | |
| CN218499030U (en) | Resistance-capacitance power circuit and power supply equipment | |
| CN217063555U (en) | Switch power supply with overvoltage protection | |
| CN218482790U (en) | AC-DC conversion module | |
| CN211830567U (en) | Lightning protection filtering power supply circuit | |
| CN220775660U (en) | Electric energy meter and power supply thereof | |
| CN219051679U (en) | High-voltage high-frequency electrostatic dust collection power supply and multistage voltage parallel device | |
| CN220042989U (en) | Surge protection circuit and switching power supply | |
| CN218276475U (en) | Miniature DC high-voltage converter | |
| CN219875474U (en) | Filter circuit and switching power supply | |
| CN208285232U (en) | Regulated power supply is protected in constant current |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |