CN216437061U

CN216437061U - Low power supply module

Info

Publication number: CN216437061U
Application number: CN202121966636.3U
Authority: CN
Inventors: 彭智; 龚超
Original assignee: Shenzhen Hi Link Electronic Co ltd
Current assignee: Shenzhen Hi Link Electronic Co ltd
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2022-05-03
Anticipated expiration: 2031-08-20

Abstract

The utility model discloses a low-power supply module which comprises an oscillation unit and a control unit, wherein the oscillation unit comprises an isolation circuit and a switch circuit, the isolation circuit is connected with the switch circuit, and the switch circuit is connected with the control unit. The utility model adopts the quasi-resonance flyback converter and the quasi-resonance controller in the power module, so that the switching tube works in a zero-voltage switching state, the loss of the switch is reduced, the EMI noise is reduced, the utility model has the advantages of small no-load loss of a circuit, high power conversion efficiency and the like, and the utility model has compact design, saves cost, has high reliability and can be more widely applied in the field with higher power requirements.

Description

Low power supply module

Technical Field

The utility model relates to the technical field of power supplies, in particular to a low-power supply module.

Background

The current electronic products on the market need to be plugged in to normally operate, but cannot be directly connected with 220V for use, because the electronic products are burnt, a conversion device is needed. However, the power conversion device in the existing market has the following problems:

(1) the volume is large, heavy and inconvenient to use;

(2) the power consumption is large, the circuit consumes much energy and is wasteful and not environment-friendly on the premise of not using power;

(3) the conversion efficiency of the power supply is low;

(4) the circuit has the advantages of complex design, low reliability, high cost, difficult maintenance and incomplete protection function.

SUMMERY OF THE UTILITY MODEL

In view of the defects in the prior art, the present invention provides a low power supply module to reduce the loss.

A low-power supply module comprises an oscillation unit and a control unit, wherein the oscillation unit comprises an isolation circuit and a switch circuit, the isolation circuit is connected with the switch circuit, and the switch circuit is connected with the control unit.

Preferably, the isolation circuit includes a first resistor, a first capacitor, a second capacitor, a first diode, and a first converter, the first converter is connected to a first end of the first resistor and a positive end of the first diode, a second end of the first resistor is connected to a first end of the first capacitor, a second end of the first capacitor is connected to a positive end of the second capacitor and a negative end of the first diode, and a negative end of the second capacitor is connected to the first converter.

Preferably, the first converter is a quasi-resonant flyback converter.

Preferably, the switch circuit includes a first switch tube and a second resistor, a drain of the first switch tube is connected to the isolation circuit, a gate of the first switch tube is connected to a first end of the second resistor, a source of the first switch tube is connected to the control unit, and a second end of the second resistor is connected to the control unit.

Preferably, the control unit includes a third resistor, a fourth resistor, a third capacitor, a fourth capacitor, and a quasi-resonant controller, the quasi-resonant controller is connected to the first end of the third resistor, the first end of the third capacitor, and the first end of the fourth capacitor, the second end of the third resistor is connected to the first end of the fourth resistor and the source of the first switch tube, and the second end of the third capacitor is connected to the second end of the fourth capacitor and the second end of the fourth resistor and grounded.

Preferably, the quasi-resonant controller is of a type including, but not limited to, L6562.

Preferably, the power supply further comprises a rectifying circuit connected with the isolation circuit.

Preferably, the device further comprises a photoelectric coupler, and the photoelectric coupler is connected with the quasi-resonance controller.

The utility model has the beneficial effects that: the quasi-resonance flyback converter and the quasi-resonance controller are adopted, so that the switching tube works in a zero-voltage switching state, the loss of a switch is reduced, the EMI noise is reduced, the quasi-resonance flyback converter has the advantages of small circuit no-load loss, high power conversion efficiency and the like, the design is compact, the cost is saved, the reliability is high, and the quasi-resonance flyback converter can be widely applied to the field with higher power requirements.

Drawings

In order to more clearly illustrate the detailed description of the utility model or the technical solutions in the prior art, the drawings that are needed in the detailed description of the utility model or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a block diagram of a low power module according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a low power supply module according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the utility model pertains.

As shown in fig. 1, a low power supply module includes an oscillation unit and a control unit, the oscillation unit includes an isolation circuit and a switch circuit, the isolation circuit is connected with the switch circuit, and the switch circuit is connected with the control unit. The control circuit also comprises a rectifying circuit and a photoelectric coupler, wherein the rectifying circuit is connected with the isolating circuit, and the photoelectric coupler is connected with the control unit.

As shown in fig. 2, the isolation circuit includes a first resistor R1, a first capacitor C1, a second capacitor C2, a first diode D1 and a first converter T1, the dotted terminal of the primary winding of the first converter T1 is connected to the rectification circuit, the dotted terminal of the primary winding of the first converter T1 is connected to the switch circuit, the dotted terminal of the secondary winding of the first converter T1 is connected to the first terminal of the first resistor R1 and the positive terminal of the first diode D1, the second terminal of the first resistor R1 is connected to the first terminal of the first capacitor C1, the second terminal of the first capacitor C1 is connected to the positive terminal of the second capacitor C2 and the negative terminal of the first diode D1, and the negative terminal of the second capacitor C2 is connected to the dotted terminal of the secondary winding of the first converter T1. The first converter T1 is a quasi-resonant flyback converter.

The switching circuit comprises a first switching tube Q1 and a second resistor R2, the drain electrode of the first switching tube Q1 is connected with the synonym end of the primary winding of a first converter T1 in the isolation circuit, the grid electrode of the first switching tube Q1 is connected with the first end of a second resistor R2, the source electrode of the first switching tube Q1 is connected with the control unit, and the second end of the second resistor R2 is connected with the control unit.

The control unit comprises a third resistor R3, a fourth resistor R4, a third capacitor C3, a fourth capacitor C4 and a quasi-resonance controller U1, a VCC pin of the quasi-resonance controller U1 is connected with the rectifying circuit, an OUT pin of the quasi-resonance controller U1 is connected with a second end of a second resistor R2 in the switching circuit, a CS pin of the quasi-resonance controller U1 is connected with a first end of a third resistor R3 and a first end of a third capacitor C3, an FB pin of the quasi-resonance controller U1 is connected with a first end of a fourth capacitor C4 and a photocoupler, a second end of the third resistor R3 is connected with a first end of the fourth resistor R4 and a source of a first switch tube Q1 in the switching circuit, and a second end of the fourth resistor R4 is connected with a second end of the third capacitor C3 and a second end of the fourth capacitor C4 and grounded. The model of the quasi-resonant controller U1 includes, but is not limited to, L6562, the CS pin of U1 is used to detect the current flowing through the first switching tube Q1, the OUT pin of U1 is used as the output drive control pin, the FB pin of U1 is used as the output feedback input pin, and the output feedback information is detected by the photocoupler.

Specifically, when the first switch Q1 is turned off, the circuit oscillates due to the leakage inductance of the first converter T1 and the output capacitance of the first switch Q1, and a spike voltage is generated across the first switch Q1, so that an RLC resonant circuit is formed. The peak voltage across the first switch Q1 starts oscillating after the flyback output current is reduced to zero, and when the oscillation reaches the lowest point, the first switch Q1 starts to conduct again. When the load in the circuit is light, the switching frequency of the first switching tube Q1 is very high, which increases the light load or no-load loss of the circuit, so a minimum off-time is set by the quasi-resonant controller U1, when the first resonance reaches the lowest, the off-time does not exceed the set minimum off-time, the first switching tube Q1 cannot be conducted, the peak voltage at both ends continues to oscillate, and the switching tube cannot be conducted again until the off-time exceeds the minimum off-time. The internal operational amplifier is calculated by detecting the primary flyback current and information fed back by the output end, and once the requirement of quasi-resonance control is met, the switch is switched on after a delay time, so that zero voltage switching-on is realized, the switching frequency is reduced, the no-load loss of a circuit is reduced, and the conversion efficiency of a power module is improved.

The utility model adopts the quasi-resonance flyback converter and the quasi-resonance controller in the power module, so that the switching tube works in a zero-voltage switching state, the loss of the switch is reduced, the EMI noise is reduced, the utility model has the advantages of small no-load loss of a circuit, high power conversion efficiency and the like, and the utility model has compact design, saves cost, has high reliability and can be more widely applied in the field with higher power requirements.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the utility model has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims

1. A low-power supply module is characterized by comprising an oscillation unit and a control unit, wherein the oscillation unit comprises an isolation circuit and a switch circuit, the isolation circuit is connected with the switch circuit, and the switch circuit is connected with the control unit;

the isolation circuit comprises a first resistor, a first capacitor, a second capacitor, a first diode and a first converter, wherein the first converter is connected with a first end of the first resistor and a positive end of the first diode;

the first converter is a quasi-resonant flyback converter.

2. The power supply module of claim 1, wherein the switch circuit comprises a first switch tube and a second resistor, a drain of the first switch tube is connected to the isolation circuit, a gate of the first switch tube is connected to a first end of the second resistor, a source of the first switch tube is connected to the control unit, and a second end of the second resistor is connected to the control unit.

3. The low power supply module of claim 2, wherein the control unit includes a third resistor, a fourth resistor, a third capacitor, a fourth capacitor, and a quasi-resonant controller, the quasi-resonant controller is connected to the first terminal of the third resistor, the first terminal of the third capacitor, and the first terminal of the fourth capacitor, the second terminal of the third resistor is connected to the first terminal of the fourth resistor and the source of the first switch transistor, and the second terminal of the third capacitor is connected to the second terminal of the fourth capacitor and the second terminal of the fourth resistor and grounded.

4. A low power supply module according to claim 3, wherein the quasi-resonant controller is of the type comprising L6562.

5. The low power supply module of claim 1, further comprising a rectifying circuit, said rectifying circuit being connected to the isolation circuit.

6. The low power supply module of claim 3, further comprising an opto-coupler, wherein the opto-coupler is coupled to the quasi-resonant controller.