CN210201743U

CN210201743U - Positive pulse switching power supply

Info

Publication number: CN210201743U
Application number: CN201920903167.7U
Authority: CN
Inventors: Shishuang Yan; 颜世双
Original assignee: Guangzhou Cologne Energy Saving Technology Co Ltd
Current assignee: Guangzhou Cologne Energy Saving Technology Co Ltd
Priority date: 2019-06-17
Filing date: 2019-06-17
Publication date: 2020-03-27
Anticipated expiration: 2029-06-17

Abstract

The utility model discloses a positive pulse switching power supply, including AC input loop, primary power loop, secondary power loop, feedback circuit and control circuit, AC input loop includes input protection circuit, EMI suppression circuit and full-bridge rectifier circuit, and primary power loop includes drain electrode clamping protection circuit, and primary power loop is through turning over the electrical connection of transformer and secondary power loop, and secondary power loop includes output rectifier circuit, control circuit includes power chip, feedback circuit's output links to each other with power chip's control end, and voltage chip's drain end links to each other with primary power loop; the utility model discloses the switching power supply who sets up controls output voltage with the effect of function blocks such as the inside pulse width modulator of power chip, and power utilization rate is high, and the output is stable, can effectively prevent the influence of unstable input voltage and interior peak voltage of circuit.

Description

Positive pulse switching power supply

Technical Field

The utility model particularly relates to a switching power supply specifically is a positive pulse switching power supply.

Background

The pulse switch power supply is one of various power supply devices, the voltage or current waveform of the pulse switch power supply is pulse-shaped, the pulse switch power supply is essentially an on-off direct current power supply, the basic working principle of the pulse switch power supply is that firstly, the primary energy source has enough energy through slow energy storage, then, the primary energy source discharges (or flows in) to an intermediate energy storage and pulse forming system, and the energy forms a pulse through storage, compression, pulse formation or conversion and other complex processes to form the pulse switch power supply.

Along with the development of the switching power supply, the miniaturization, modularization and intellectualization of the power supply are more and more concerned by people, the power supply utilization efficiency of the switching power supply on the current market is not high, a switching tube of the switching power supply is easily damaged due to peak voltage in a circuit, and when the input voltage is unstable, the power supply circuit is also easily influenced, so that aiming at the problems, a pulse switching power supply which can effectively output and is not influenced by unstable input voltage and peak voltage is needed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a positive pulse switching power supply to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

the utility model provides a positive pulse switching power supply, includes AC input loop, primary power loop, secondary power loop, feedback circuit and control circuit, AC input loop includes input protection circuit, EMI suppression circuit and full-bridge rectifier circuit, and primary power loop includes drain electrode clamp protection circuit, and primary power loop is through turning over flyback transformer and secondary power loop electricity and link to each other, and secondary power loop is including output rectifier circuit, control circuit includes the power chip, feedback circuit's output links to each other with the control end of power chip, and the drain end of voltage chip links to each other with primary power loop.

As a further aspect of the present invention: the primary power loop is composed of a drain output end D of a power chip, a primary side T1 of a flyback transformer and an input filter capacitor C1.

As a further aspect of the present invention: the input protection circuit consists of an NTC thermistor Rt1 and a fuse F1 which are connected in parallel at an alternating current input end.

As a further aspect of the present invention: the EMI suppression circuit includes a safety capacitance Cx1 and a common mode inductance L1.

As a further aspect of the present invention: the drain electrode clamping protection circuit comprises a resistor R1, a capacitor C2 and a diode D1, wherein the anode of the D1 is connected with the drain electrode of the power chip, the R1 and the C2 are connected in parallel to the output end of the full-bridge rectifying circuit, and the cathode of the D1 is connected in series with the R1 and the C2 which are connected in parallel.

As a further aspect of the present invention: the feedback circuit comprises a controllable precise voltage-stabilizing source TL431 and an optocoupler PCB817, an output voltage end of the secondary power loop is connected with resistors R2 and R3, R2 and R3 obtain sampling voltage and are connected with an input end of the TL431, an output end of the TL431 is connected with an emitter end of the PCB817, and a cathode end of the PCB817 is connected with a control end of a power chip.

As a further aspect of the present invention: the power supply chip is a Top Switch series chip, the power supply chip adopts a TOP227Y model chip, and a control pin circuit of the TOP227Y is formed by connecting a capacitor C6 and a resistor R4 in series.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the switching power supply provided by the utility model utilizes the function of functional blocks such as the pulse width modulator inside the Top Switch series power supply chip to control the output voltage, has high power utilization rate and stable output, and can effectively prevent the influence of unstable input voltage and peak voltage in the circuit;

2. the utility model has the advantages that the arranged drain electrode clamping protection circuit can inhibit the peak voltage generated by leakage inductance when the switch tube is turned off, and prevent the switch tube from being damaged;

3. the utility model discloses Rt1 is used for preventing among the input protection circuit of setting that start surge current causes the damage to devices such as rectifier bridge, switch tube, and the F1 of setting is used for preventing that the overcurrent that power or load failure arouse from causing the damage to the power.

Drawings

Fig. 1 is a schematic circuit diagram of a positive pulse switching power supply.

Fig. 2 is a schematic diagram of a circuit loop in the positive pulse switching power supply.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Please refer to fig. 1-2, in an embodiment of the present invention, a positive pulse switching power supply, includes an ac input loop, a primary power loop, a secondary power loop, a feedback circuit and a control circuit, the ac input loop includes an input protection circuit, an EMI suppression circuit and a full bridge rectifier circuit, the primary power loop includes a drain clamping protection circuit, the primary power loop is electrically connected to the secondary power loop through a flyback transformer, the secondary power loop includes an output rectifier circuit, the control circuit includes a power chip, an output end of the feedback circuit is connected to a control end of the power chip, and a drain end of the voltage chip is connected to the primary power loop.

The primary power loop is composed of a drain output end D of a power chip, a primary side T1 of a flyback transformer and an input filter capacitor C1.

The input protection circuit consists of an NTC thermistor Rt1 and a fuse F1 which are connected in parallel with an alternating current input end, wherein Rt1 is used for preventing the damage of startup surge current to devices such as a rectifier bridge and a switching tube, and Fl is used for preventing the damage of overcurrent caused by power supply or load faults to the power supply.

The EMI suppression circuit comprises a safety capacitor Cx1 and a common-mode inductor L1, Cx1 and L1 which are used for eliminating differential mode conducted interference and common-mode conducted interference in alternating current respectively.

The drain electrode clamping protection circuit comprises a resistor R1, a capacitor C2 and a diode D1, wherein the anode of the D1 is connected with the drain electrode of the power chip, the R1 and the C2 are connected in parallel to the output end of the full-bridge rectification circuit, the cathode of the D1 is connected in series with the R1 and the C2 which are connected in parallel, and the drain electrode clamping protection circuit is used for inhibiting the damage of spike voltage generated by leakage inductance when the switching tube is turned off to the switching tube.

The feedback circuit comprises a controllable precise voltage-stabilizing source TL431 and an optocoupler PCB817, an output voltage end of the secondary power loop is connected with resistors R2 and R3, R2 and R3 obtain sampling voltage and are connected with an input end of the TL431, an output end of the TL431 is connected with an emitter end of the PCB817, and a cathode end of the PCB817 is connected with a control end of a power chip.

The power chip is a Top Switch series chip, the power chip adopts a TOP227Y model chip, a control pin circuit of the TOP227Y is composed of a capacitor C6 and a resistor R4 in series connection, wherein the C6 is used for filtering spike voltage of a control end and determining automatic restart frequency and is used for carrying out loop compensation for a feedback control loop together with the R4, the control end C of the TOP227Y is connected with an emitter end of a PCB817, a source end S of the TOP227Y is grounded, and a drain end D of the TOP227Y is electrically connected with a primary winding of a flyback transformer.

The utility model discloses a theory of operation is: the utility model discloses NTC thermistor Rt1 and fuse F1 constitute input protection circuit, Rt1 is used for preventing that start-up surge current from causing the damage to devices such as rectifier bridge, switch tube, F1 is used for preventing that the overcurrent that power or load trouble arouse from causing the damage to the power; the safety capacitor Cx1 and the common-mode inductor L1 form an alternating current EMI suppression circuit which is used for eliminating differential mode conducted interference and common-mode conducted interference in alternating current respectively; BR1 and C1 constitute the input rectification filter circuit, convert sinusoidal alternating current to high-voltage pulsating direct current. The R1, the C2 and the D1 form a drain electrode clamping protection circuit which is used for inhibiting peak voltage generated by leakage inductance when the switch tube is turned off and preventing the switch tube from being damaged. An output rectifying and filtering circuit composed of D2, C3 and C4 converts output voltage into high-frequency pulsating direct current voltage, high-frequency ripple voltage is filtered by L2 and C5, the output voltage is divided by R2 and R3 to obtain sampling voltage, the sampling voltage is compared with a 2.5V reference voltage source in U3(TL431) to output error voltage, and an anti-lock current is formed by an optical coupler U2(PCB817) and flows into TOP227Y to directly control duty ratio, so that stable output voltage is obtained. The C6 is used to filter the peak voltage at the control end and determine the automatic restart frequency, and together with the R4, the safety capacitor C9 is used to filter the common mode distortion generated by the coupling capacitor between the primary and secondary.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a positive pulse switching power supply, includes AC input loop, primary power loop, secondary power loop, feedback circuit and control circuit, its characterized in that, AC input loop includes input protection circuit, EMI suppression circuit and full-bridge rectifier circuit, and primary power loop includes drain electrode clamp protection circuit, and primary power loop passes through flyback transformer and secondary power loop electrical connection, and secondary power loop includes output rectifier circuit, control circuit includes the power chip, feedback circuit's output links to each other with the control end of power chip, and the drain terminal of voltage chip links to each other with primary power loop.

2. The positive pulse switching power supply as claimed in claim 1, wherein the primary power loop is formed by a drain output terminal D of a power chip, a primary side T1 of a flyback transformer and an input filter capacitor C1.

3. The positive pulse switching power supply according to claim 1, wherein said input protection circuit is composed of an NTC thermistor Rt1 and a fuse F1 connected in parallel at the ac input terminal.

4. The positive-pulse switching power supply according to claim 1, wherein the EMI suppression circuit comprises a safety capacitance Cx1 and a common mode inductance L1.

5. The positive pulse switching power supply according to claim 1, wherein the drain clamp protection circuit comprises a resistor R1, a capacitor C2 and a diode D1, wherein the anode of D1 is connected to the drain of the power supply chip, R1 and C2 are connected in parallel to the output terminal of the full bridge rectifier circuit, and the cathode of D1 is connected in series with the parallel R1 and C2.

6. The positive pulse switching power supply as claimed in claim 1, wherein the feedback circuit comprises a controllable precise voltage-stabilized source TL431 and an optocoupler PCB817, an output voltage end of the secondary power loop is connected with resistors R2 and R3, R2 and R3 obtain sampling voltages and are connected with an input end of the TL431, an output end of the TL431 is connected with an emitter end of the PCB817, and a cathode end of the PCB817 is connected with a control end of the power chip.

7. The positive pulse switching power supply according to any one of claims 1-6, wherein the power supply chip is a TopSwitch series chip, the power supply chip is a chip of TOP227Y type, and a control pin circuit of TOP227Y is composed of a capacitor C6 and a resistor R4 in series.