CN216794867U

CN216794867U - Switch power supply circuit driven by multiple parallel transformers

Info

Publication number: CN216794867U
Application number: CN202220023185.8U
Authority: CN
Inventors: 董林原
Original assignee: Hebei Huineng Xinyuan Electronic Technology Co ltd
Current assignee: Hebei Huineng Xinyuan Electronic Technology Co ltd
Priority date: 2022-01-05
Filing date: 2022-01-05
Publication date: 2022-06-21
Anticipated expiration: 2032-01-05

Abstract

The utility model discloses a switch power supply circuit driven by a plurality of transformers in parallel, which comprises a drive control circuit, a plurality of isolation transformers and a multi-output rectification filter circuit, wherein the isolation transformers are controlled by the same drive control circuit, namely, two ends of a winding after primary windings of the isolation transformers are connected in parallel are respectively connected with an output end and a power supply end of the drive control circuit, and each secondary winding of each isolation transformer is connected with the output rectification filter circuit. The utility model utilizes the single-circuit driving control circuit to control the plurality of isolation transformers, thereby realizing the electrical isolation of the primary and secondary of the plurality of isolation transformers and forming the multi-path shunt output.

Description

Switch power supply circuit driven by multiple parallel transformers

Technical Field

The utility model belongs to the technical field of switching power supplies, and particularly relates to a switching power supply circuit driven by a plurality of transformers in parallel.

Background

In present fly back switching power supply circuit, what adopt usually is that drive control corresponds a transformer all the way, realizes primary and secondary isolation transform, if when needing multichannel isolator power supply in an equipment, this kind of scheme will have a problem and shortcoming, and especially a plurality of transformers need correspond a plurality of drive control circuit, will cause like this that product cost increases, and the condition that spatial layout increases for the circuit becomes complicated, and the design degree of difficulty increases.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is to provide a switching power supply circuit driven by a plurality of transformers in parallel, so that one-way driving control of the plurality of transformers is realized, thereby reducing the space layout and design difficulty and reducing the cost.

In order to solve the problems, the technical scheme adopted by the utility model is as follows:

a plurality of parallel driving switch power supply circuits of transformers comprises a driving control circuit, a plurality of isolation transformers and a multi-output rectifying and filtering circuit, wherein the isolation transformers are controlled by the same driving control circuit, namely, two ends of a winding are connected with two ends of a primary winding of each isolation transformer in parallel and are respectively connected with an output end and a power supply end of the driving control circuit, and each secondary winding of each isolation transformer is connected with the output rectifying and filtering circuit.

Furthermore, the driving control circuit comprises a driving control chip and a power switch tube, and the output of the driving control chip is connected with the control end of the power switch tube.

Furthermore, the power switch tube is an MOS tube, the grid electrode of the MOS tube is a control end, the source electrode of the MOS tube is grounded through a resistor, and the drain electrode of the MOS tube is connected with one end of the primary winding of the isolation transformer.

Preferably, the driving control chip is a PWM chip.

Furthermore, the drive control circuit further comprises a slow start circuit, the slow start circuit comprises a resistor and a capacitor, the capacitor is connected to two ends of the input power supply in parallel, and the resistor is connected between the positive end of the power supply and the power supply pin of the drive control chip in series.

Furthermore, one secondary winding of one of the isolation transformers is a feedback winding, one end of the feedback winding is grounded, the other end of the feedback winding is connected with the feedback input end of the driving control circuit through a resistor and a diode in sequence, and the feedback input end of the driving control circuit is grounded through a capacitor.

Further, the output rectifying and filtering circuit comprises a rectifying diode and a filtering capacitor, wherein the anode of the rectifying diode is connected with one end of the secondary coil of the isolation transformer, the cathode of the rectifying diode is a rectifying output positive end, the other end of the secondary coil of the isolation transformer is a rectifying output ground, and the filtering capacitor is connected in parallel between the rectifying output positive end and the rectifying output ground.

Furthermore, the isolation transformer is provided with one or more secondary windings, and each secondary winding is connected with one path of rectifying and filtering circuit.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

the utility model uses the single-path driving control circuit to control the plurality of isolation transformers, thereby realizing the electrical isolation of the primary and secondary sides of the plurality of isolation transformers and forming the multi-path shunt output.

Drawings

FIG. 1 is a block circuit diagram of the present invention;

fig. 2 is a schematic diagram of the circuit of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the disclosed embodiments are merely exemplary of the utility model, and are not intended to be exhaustive or exhaustive. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The utility model relates to a multi-transformer parallel driving switch power supply circuit, which is used for solving the problem that a plurality of transformers need to correspond to a plurality of driving control circuits in the existing design.

As shown in fig. 1 and fig. 2, the present invention includes a driving control circuit, a slow start circuit, a plurality of isolation transformers and a multi-output rectifying and filtering circuit, wherein the isolation transformers are controlled by the same driving control circuit, that is, after the primary windings of the isolation transformers are connected in parallel, two ends of the primary windings are respectively connected to the output end and the power end of the driving control circuit, and each secondary winding of each isolation transformer is connected to the output rectifying and filtering circuit.

In a preferred embodiment of the present invention, the driving control circuit includes a driving control chip and a power switch V2, and an output of the driving control chip is connected to a control terminal of the power switch. More specifically, the power switch tube V2 is a MOS tube, a gate of the MOS tube is a control end, and is connected to an output of the driving control chip, a source of the MOS tube V2 is grounded via a resistor R2, and a drain of the MOS tube V2 is connected to one end of a primary winding of the isolation transformer, specifically, in the embodiment of the present invention, a drain of the MOS tube V2 is respectively connected to a T1-5 end (primary windings T1-5 and T1-6) of the isolation transformer T1 and a T2-5 end (primary windings T2-5 and T2-6) of the isolation transformer T2. The driving control chip is a PWM chip, and as a preferred embodiment, chips with 8 pins, such as UC3844 and UC3845, can be selected.

The slow start circuit comprises a resistor R3 and a capacitor C1, wherein the capacitor C1 is connected in parallel to two ends of an input power supply, and the resistor R3 is connected in series between a positive power supply end and a power supply pin of the drive control chip.

In order to control the output waveform of a PWM chip (drive control circuit) and stabilize the output, one secondary winding of one of the isolation transformers is a feedback winding, for the utility model, the isolation transformer T2 provides feedback specifically, one end of the feedback winding (T2-3 and T2-4) is grounded, the other end of the feedback winding (T2-3 and T2-4) is connected with the feedback input end of the drive control circuit through a resistor R1 and a diode V1 in sequence, and the feedback input end of the drive control circuit is grounded through a capacitor C2.

For the utility model, the output rectifying and filtering circuit comprises a rectifying diode and a filtering capacitor, wherein the anode of the rectifying diode is connected with one end of the secondary coil of the isolation transformer, the cathode of the rectifying diode is a rectifying output positive end, the other end of the secondary coil of the isolation transformer is a rectifying output ground, and the filtering capacitor is connected in parallel between the rectifying output positive end and the rectifying output ground.

The isolation transformer is provided with one or more secondary windings, and each secondary winding is connected with a rectifying and filtering circuit, as shown in fig. 2.

Brief description of the principles

For the utility model, the drive control circuit and the power switch tube have the functions of pulse width modulation to realize output voltage stabilization; the function of the isolation transformer is to achieve transformer primary and secondary energy transfer, scaling and electrical isolation. In addition, the isolation transformer is composed of a primary side and a secondary side, and the primary sides of the isolation transformers are connected in parallel, which is specifically shown in fig. 2. The secondary side of the isolation transformer is connected with the multi-output rectifying and filtering circuit, as shown in fig. 2, the secondary side of the isolation transformer T1 is composed of 4 output rectifying and filtering circuits Vo1, Vo2, Vo3 and Vo4, and the output rectifying and filtering circuits are isolated from each other. The secondary side of the isolation transformer T2 is composed of 3 paths of output rectifying and filtering circuits Vo5, Vo6 and Vo7, and the output rectifying and filtering circuits are isolated from one another.

As shown in fig. 2, when the input dc voltage charges the capacitor C1 and reaches a certain value, the driving control circuit starts to operate to turn on or off the MOS transistor V2; when V2 is turned on, the primary winding (T1-5/T1-6) of transformer T1 and the primary winding (T2-5/T2-6) of transformer T2 store energy at the same time, and when V2 is turned off, the magnetic field energy in the transformer discharges energy to the output end through transformer T1, the secondary winding of transformer T2 and each shunt diode; meanwhile, a winding T2-3/T2-4 of the transformer T2 is rectified and filtered by a diode V1 and a capacitor C2 and then fed back to the drive control circuit for PWM regulation control, so that output voltage stabilization is realized.

The specific embodiment of the utility model provides that the single-path drive control circuit controls two isolation transformers to realize primary and secondary electrical isolation. Certainly, the number of the isolation transformers can also be multiple, that is, a single-path driving control circuit can be adopted to control the multiple transformers, so that the primary and secondary electric isolation is realized.

Claims

1. A switching power supply circuit driven by a plurality of transformers in parallel is characterized in that: the multi-path isolation transformer driving circuit comprises a driving control circuit, a plurality of isolation transformers and a multi-path output rectifying and filtering circuit, wherein the isolation transformers are controlled by the same driving control circuit, namely, the two ends of a winding are respectively connected with the output end and the power end of the driving control circuit after primary windings of the isolation transformers are connected in parallel, and each secondary winding of each isolation transformer is connected with the output rectifying and filtering circuit.

2. The multiple-transformer parallel-drive switching power supply circuit according to claim 1, wherein: the drive control circuit comprises a drive control chip and a power switch tube, and the output of the drive control chip is connected with the control end of the power switch tube.

3. The multiple-transformer parallel-drive switching power supply circuit according to claim 2, wherein: the power switch tube is an MOS tube, the grid electrode of the MOS tube is a control end, the source electrode of the MOS tube is grounded through a resistor, and the drain electrode of the MOS tube is connected with one end of a primary winding of the isolation transformer.

4. A multiple transformer parallel drive switching power supply circuit according to claim 3, wherein: the drive control chip is a PWM chip.

5. The multiple-transformer parallel-drive switching power supply circuit according to claim 4, wherein: the drive control circuit further comprises a slow starting circuit, the slow starting circuit comprises a resistor and a capacitor, the capacitor is connected to two ends of the input power supply in parallel, and the resistor is connected between the positive end of the power supply and the power supply pin of the drive control chip in series.

6. A multiple transformer parallel drive switching power supply circuit according to any one of claims 1-5, wherein: one secondary winding of one of the isolation transformers is a feedback winding, one end of the feedback winding is grounded, the other end of the feedback winding is connected with the feedback input end of the driving control circuit through a resistor and a diode in sequence, and the feedback input end of the driving control circuit is grounded through a capacitor.

7. The multiple-transformer parallel-drive switching power supply circuit according to claim 6, wherein: the output rectifying and filtering circuit comprises a rectifying diode and a filtering capacitor, wherein the anode of the rectifying diode is connected with one end of the secondary coil of the isolation transformer, the cathode of the rectifying diode is a rectifying output positive end, the other end of the secondary coil of the isolation transformer is a rectifying output ground, and the filtering capacitor is connected between the rectifying output positive end and the rectifying output ground in parallel.

8. The multiple-transformer parallel-drive switching power supply circuit according to claim 7, wherein: the isolation transformer is provided with one or more secondary windings, and each secondary winding is connected with one path of rectifying and filtering circuit.