CN211405888U

CN211405888U - Double-output switching power supply circuit

Info

Publication number: CN211405888U
Application number: CN202020356883.0U
Authority: CN
Inventors: 林毅
Original assignee: Fuzhou Sonja Electronic Technology Co ltd
Current assignee: Fuzhou Sonja Electronic Technology Co ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-09-01
Anticipated expiration: 2030-03-19

Abstract

The utility model discloses a double-output switch power supply circuit, including input filter circuit, input rectifier circuit and high frequency transformer, be equipped with first, second secondary winding in the high frequency transformer, first secondary winding exports the drive load after through first output rectifier circuit, first output filter circuit, and second secondary winding exports the drive load after through second output rectifier circuit, second output filter circuit again through annular inductance LF 2; one end of a primary winding of the high-frequency transformer is connected with a collector of a switch tube Q1, a base of the switch tube Q1 is connected with a sixth pin of a control chip AIC4 through a resistor R5, the sixth pin is connected with a resistor R6, the other end of the primary winding is connected with a fifth pin of the AIC4 through resistors R3 and R17, an emitter of the switch tube Q1 is connected with a fourth pin of the control chip AIC4 through resistors R7 and R8 which are connected in parallel, and a feedback winding is arranged in the high-frequency transformer and connected with the fifth pin and the fourth pin of the AIC 4.

Description

Double-output switching power supply circuit

Technical Field

The utility model relates to a power supply circuit technical field especially relates to a double output switch power supply circuit.

Background

The power supply is a product which is not negligible in the electronic manufacturing industry, is widely applied, and in the electronic industry and various scientific and technical fields, the stable power supply is the basis for reliable operation of electronic products, can provide power for electronic equipment, and ensures long-term operation of the electronic equipment. However, when the alternating voltage and current generated by the power supply pass through other components in the circuit, interference can be generated, even high-frequency signals are affected, and if measures are not taken for suppression, elimination and shielding, normal operation can be seriously affected.

In the prior art, a switching power supply circuit is usually adopted to reduce interference signals in current and ensure the stability and reliability of a power supply. However, the existing switching power supply circuit usually has only one-way output, and the working efficiency of the switching power supply transformer with the one-way output is low; when different loads are driven, the loads connected to the switching power supply with one-way output are likely to interfere with each other.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problem, an object of the utility model is to provide a two-way output switch power supply circuit becomes DC power supply through the AC power supply who at first will inputs, then adopts two way DC power supply of two way channel output, and the transformer utilization efficiency among the improvement circuit has the constant voltage power supply of two-way DC output moreover and is fit for the different load of drive, and accommodation is wider.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a double-output switch power supply circuit comprises an input filter circuit, an input rectifying circuit and a high-frequency transformer, wherein a primary winding of the high-frequency transformer is connected with the input rectifying circuit, a first secondary winding and a second secondary winding are arranged in the high-frequency transformer, the first secondary winding outputs a driving load after passing through a first output rectifying circuit and a first output filter circuit, and the second secondary winding outputs the driving load after passing through a second output rectifying circuit and a second output filter circuit and then through an annular inductor LF 2; one end of the primary winding is connected with a collector of a switch tube Q1, a base of the switch tube Q1 is connected with a sixth pin of a control chip AIC4 through a resistor R5, a resistor R6 is further connected to the sixth pin of the control chip AIC4, the other end of the primary winding is connected with a fifth pin of the control chip AIC4 through resistors R3 and R17, an emitter of the switch tube Q1 is connected with the fourth pin of the control chip AIC4 through resistors R7 and R8 which are connected in parallel, and a feedback winding is further arranged in the high-frequency transformer and connected with the fifth pin and the fourth pin of the control chip AIC 4.

Furthermore, an optical coupling detection circuit and a protection circuit are connected to a second pin of the control chip AIC4, and the optical coupling detection circuit and the protection circuit are connected to output ends of the first output rectification circuit and the second output rectification circuit respectively.

Furthermore, a capacitor C18, a resistor R19 and a resistor R2 which are connected in parallel are arranged at two ends of the primary winding of the high-frequency transformer.

Further, one end of the feedback winding is connected with the fifth pin of the control chip AIC4 through a diode D6 and a resistor R4.

Furthermore, the model of the control chip AIC4 is CR 6850C.

Further, a first output indicator light LED1 is arranged in a circuit behind the first output filter circuit, and a second output indicator light LED2 is arranged in a circuit behind the annular inductor LF 2.

The utility model discloses following beneficial effect has:

1. the utility model discloses adopt CR6850C control chip among the switching power supply circuit, adopt flyback isolation AC-DC switching power supply framework, be equipped with two sets of independent secondary windings among the high frequency transformer, be equipped with the independent direct current output circuit of double-circuit, power work efficiency is high, the power is fit for driving different loads, accommodation is wider;

2. the utility model discloses primary winding and secondary winding's opposite phase in the high frequency transformer, two output circuit are flyback rectifier output, and wherein the output circuit behind the annular inductance can filter noise, and the stabilizing current reaches and suppresses electromagnetic interference for output power supply is purer stable.

Drawings

Fig. 1 is a schematic diagram of the dual output switching power supply circuit of the present invention.

Description of reference numerals:

1. an input filter circuit; 2. an input rectification circuit; 3. a high-frequency transformer; 31. a primary winding; 32. a first secondary winding; 33. a second secondary winding; 34. a feedback winding; 4. a first output rectifying circuit; 5. a first output filter circuit; 6. a second output rectifying circuit; 7. a second output filter circuit; 8. an opto-coupler detection circuit; 9. and a protection circuit.

Detailed Description

The invention will be described in further detail with reference to the following drawings and specific embodiments:

referring to fig. 1, the dual-output switching power supply circuit includes an input filter circuit 1, an input rectifier circuit 2 and a high-frequency transformer 3, a primary winding 31 of the high-frequency transformer 3 is connected to the input rectifier circuit 2, a first secondary winding 32 and a second secondary winding 33 are arranged in the high-frequency transformer 3, the first secondary winding 32 outputs a driving load after passing through a first output rectifier circuit 4 and a first output filter circuit 5, and the second secondary winding 33 outputs the driving load after passing through a second output rectifier circuit 6 and a second output filter circuit 7 and then through an annular inductor LF 2; one end of the primary winding 31 is connected with a collector of a switching tube Q1, a base of the switching tube Q1 is connected with a sixth pin of a control chip AIC4 through a resistor R5, a resistor R6 is further connected to the sixth pin of the control chip AIC4, the other end of the primary winding 31 is connected with a fifth pin (power supply input end) of the control chip AIC4 through resistors R3 and R17, an emitter of the switching tube Q1 is connected with the fourth pin of the control chip AIC4 through resistors R7 and R8 which are connected in parallel, and a feedback winding 34 is further arranged in the high-frequency transformer 3 and connected with the fifth pin and the fourth pin (feedback input end) of the control chip AIC 4. And a capacitor C18, a resistor R19 and a resistor R2 which are connected in parallel are arranged at two ends of the primary winding 31 of the high-frequency transformer 3. One end of the feedback winding 34 is connected with the fifth pin of the control chip AIC4 through a diode D6 and a resistor R4.

The mains supply is filtered by the input filter circuit 1, and the input filter circuit 1 is internally provided with a capacitor C9 and an inductor LF3, so that electromagnetic noise and clutter signals of an input power supply are suppressed, the interference to the power supply is prevented, and meanwhile, the interference of high-frequency clutter generated by the power supply to a power grid is also prevented; the filtered alternating voltage is rectified by the input rectifying circuit 2 and then filtered by the capacitor C28 to obtain pure direct voltage.

The sum of the resistances of the resistors R3 and R17 determines the starting time of the control chip AIC 4. The capacitor C12, the resistor R17, the resistor R8 and the resistor R7 form a buffer which is connected with the MOS switch tube Q1 in parallel. The voltage stress of the switching tube Q1 is reduced, the EMI is reduced, and secondary breakdown is avoided; resistors R5, R6 determine the Q1 switching speed. When the switching tube Q1 is turned off, the primary winding 31 of the high-frequency transformer 3 is prone to generate spike voltage and current, so the combination of the capacitor C18 and the resistors R19 and R2 can well absorb the spike voltage and current. The primary winding 31 and the

secondary windings

32, 33 of the high frequency transformer 3 are in opposite phase and the secondary windings are in opposite phase. The

secondary windings

32, 33 are both flyback rectified outputs.

The first output rectifying circuit 4 is provided with rectifying diodes D9 and D7, the second output rectifying circuit 6 is provided with rectifying diodes D8 and D10, and a resistor R9, a capacitor C3, a resistor R20 and a capacitor C17 in the circuit are peak clipping circuits. The first output filter circuit 5 is provided with filter capacitors C21 and C22, and the second output filter circuit 7 is provided with filter capacitors C24 and C25. The resistors R10, R18 in the first output circuit are output loads.

And a second pin of the control chip AIC4 is connected with an optical coupling detection circuit 8 and a protection circuit 9, and the optical coupling detection circuit 8 and the protection circuit 9 are respectively connected with output ends of the first output rectification circuit 4 and the second output rectification circuit 6. An optical coupler IC is arranged in the optical coupler detection circuit 8, and an IC3 is arranged in the protection circuit 9.

The model of the control chip AIC4 is CR 6850C. The control chip CR6850C (including CR6853) is a control IC for a 36W inline switching power supply, which is a high-integration, low-power consumption current mode PWM control chip suitable for a low-power supply module of an offline AC-DC flyback topology. The control chip can change the working frequency through an external resistor; under the conditions of light load and no load, the PFM and the CRM are automatically started, so that the standby power consumption of the power module can be effectively reduced, and the aims of environmental friendliness and energy conservation are fulfilled.

CR6850C has a very low start-up current, so a 2 mega ohm start-up resistance can be used. In order to improve the stability of the system and prevent subharmonic oscillation, a synchronous slope compensation circuit is built in the CR 6850C; the dynamic peak limiting circuit reduces the change of the maximum output power when the voltage is input in a wide range (90V-264V); the built-in leading edge blanking circuit can eliminate the interference generated by each turn-on of the switching tube. CR6850C has built-in multiple protection functions: overvoltage protection, cycle-by-cycle peak current limiting, undervoltage locking (short circuit and overcurrent protection can be realized by using the undervoltage locking device) and output drive high-level clamping below 16.8V; and the totem pole and the soft drive adopted by the drive output effectively reduce the switching noise.

A first output indicator light LED1 is arranged in a circuit behind the first output filter circuit 5, and a second output indicator light LED2 is arranged in a circuit behind the annular inductor LF 2. It is convenient to indicate the output working state independently.

The above only is the detailed implementation manner of the present invention, not limiting the patent scope of the present invention, all the equivalent structure changes made in the specification and the attached drawings or directly or indirectly applied to other related technical fields are included in the patent protection scope of the present invention.

Claims

1. The utility model provides a two-way output switching power supply circuit, includes input filter circuit (1), input rectifier circuit (2) and high frequency transformer (3), primary winding (31) of high frequency transformer (3) link to each other with input rectifier circuit (2), its characterized in that: the high-frequency transformer (3) is internally provided with a first secondary winding (32) and a second secondary winding (33), the first secondary winding (32) outputs a driving load after passing through a first output rectifying circuit (4) and a first output filter circuit (5), and the second secondary winding (33) outputs the driving load after passing through a second output rectifying circuit (6) and a second output filter circuit (7) and then passing through an annular inductor LF 2; one end of the primary winding (31) is connected with a collector of a switching tube Q1, a base of the switching tube Q1 is connected with a sixth pin of a control chip AIC4 through a resistor R5, a resistor R6 is further connected to the sixth pin of the control chip AIC4, the other end of the primary winding (31) is connected with a fifth pin of the control chip AIC4 through resistors R3 and R17, an emitter of the switching tube Q1 is connected to the fourth pin of the control chip AIC4 through resistors R7 and R8 which are connected in parallel, and a feedback winding (34) is further arranged in the high-frequency transformer (3) and connected with the fifth pin and the fourth pin of the control chip AIC 4.

2. A dual output switching power supply circuit as defined in claim 1, wherein: and a second pin of the control chip AIC4 is connected with an optical coupling detection circuit (8) and a protection circuit (9), and the optical coupling detection circuit (8) and the protection circuit (9) are respectively connected with output ends of the first output rectifying circuit (4) and the second output rectifying circuit (6).

3. A dual output switching power supply circuit as defined in claim 1, wherein: and a capacitor C18, a resistor R19 and a resistor R2 which are connected in parallel are arranged at two ends of a primary winding (31) of the high-frequency transformer (3).

4. A dual output switching power supply circuit as defined in claim 1, wherein: one end of the feedback winding (34) is connected with the fifth pin of the control chip AIC4 through a diode D6 and a resistor R4.

5. A dual output switching power supply circuit as defined in claim 1, wherein: the model of the control chip AIC4 is CR 6850C.

6. A dual output switching power supply circuit as defined in claim 1, wherein: and a first output indicator light LED1 is arranged in a circuit behind the first output filter circuit (5), and a second output indicator light LED2 is arranged in a circuit behind the annular inductor LF 2.