CN201430533Y

CN201430533Y - Power source circuit

Info

Publication number: CN201430533Y
Application number: CN2009201337835U
Authority: CN
Inventors: 许于星; 黄昌宾; 于吉永
Original assignee: China Great Wall Computer Shenzhen Co Ltd
Current assignee: China the Great Wall science and technology group Limited by Share Ltd
Priority date: 2009-07-09
Filing date: 2009-07-09
Publication date: 2010-03-24
Anticipated expiration: 2019-07-09

Abstract

The utility model provides a power source circuit, which is adaptable to the technical field of power sources. The power source circuit comprises a rectifier-filter circuit, an absorption circuit, a voltage transformation circuit and an output circuit which are sequentially connected; the power source circuit further comprises a feedback circuit connected with the output circuit and a control circuit which is respectively connected with the rectifier-filter circuit, the absorption circuit, the voltage transformation circuit and the feedback circuit; the control circuit can perform over-voltageprotection on the power source circuit when detecting voltage of the voltage transformation circuit rises. Compared with a conventional power source circuit, the power source circuit can save an output over-voltage protection circuit, and realize over-voltage protection of output voltage of the power source circuit by utilizing the self-contained over-voltage protection function of the control circuit, thereby reducing production cost. The power source circuit also has the advantages of high over-voltage protection accuracy and sensitive protection control reaction.

Description

A kind of power circuit

Technical field

The utility model belongs to the technical field of power supply, relates in particular to a kind of power circuit.

Background technology

Conventional power source is in order to realize the output voltage overvoltage protection; all overvoltage crowbar must be set in circuit; Fig. 1 shows the structure of conventional power source circuit; the conventional power source circuit comprises current rectifying and wave filtering circuit 10; absorb circuit 20; transforming circuit 30; output circuit 40; feedback circuit 50; control circuit 60 and output over-voltage protection circuit 70; output over-voltage protection circuit 70 detects the whether overvoltage of output voltage of output circuits 40; if output voltage overvoltage; output over-voltage protection circuit 70 disconnects the power supply of the control chip U1 of control circuit 60; thereby stop the work of power circuit, play the effect of overvoltage protection.

But; this power circuit is because structure is complicated; so production cost height; again owing to comprise the second voltage-stabiliser tube ZD2 and the first triode Q1 that the parameter error scope is big in the output over-voltage protection circuit 70; cause the overvoltage protection precision of this power circuit not high; because output over-voltage protection circuit 70 sends to control chip U1 by the second photoelectrical coupler U4 with testing result, and the second photoelectrical coupler U4 can produce certain time of delay, cause the protection control reaction of this power circuit insensitive again.

The utility model content

The purpose of this utility model is to provide a kind of power circuit, is intended to solve that there is the production cost height in the existing power supply circuit, the overvoltage protection precision is not high and the insensitive problem of protection control reaction.

The utility model is to realize like this; a kind of power circuit; described power circuit comprises current rectifying and wave filtering circuit, absorption circuit, transforming circuit and the output circuit that links to each other successively; described power circuit also comprises the feedback circuit that is connected with described output circuit; and respectively with described current rectifying and wave filtering circuit, absorb the control circuit that circuit, transforming circuit are connected with feedback circuit; the voltage that described control circuit detects transforming circuit raises, and described power circuit is carried out overvoltage protection.

In the said structure, described transforming circuit comprises first primary coil, second primary coil and secondary coil, the described absorption circuit of two terminations of described first primary coil, the described output circuit of two terminations of described secondary coil, the described control circuit of first termination of described second primary coil, the second end ground connection of described second primary coil.

In the said structure, described control circuit comprises control chip, first resistance, second resistance, the 3rd resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, second electric capacity, the 3rd electric capacity, the 4th electric capacity, the 5th electric capacity and second diode, the startup leads ends of described control chip is by first resistance of serial connection, second resistance and the 3rd resistance connect the output of described current rectifying and wave filtering circuit, three drain electrode ends of the inside integrated MOS FET pipe of described control chip are connected with second end of first primary coil of described absorption circuit and described transforming circuit respectively together, the current peak test side of described control chip is by the 5th grounding through resistance, the described feedback circuit of feedback termination of described control chip, and respectively by second electric capacity, the 6th resistance, and the 3rd electric capacity and the 5th capacity earth of serial connection, the contact of described the 3rd electric capacity and the 5th electric capacity connects first end of described second primary coil by the 7th resistance, the power end first via of described control chip is by the 4th capacity earth, described power end the second tunnel is by second diode and the 8th resistance first end that connects described second primary coil of serial connection, the ground end ground connection of described control chip.

In the said structure, described control chip is the DM0270 chip.

In the utility model; this power circuit is compared with the conventional power source circuit; saved the output over-voltage protection circuit; and the over-voltage protecting function that utilizes control circuit to carry is realized power circuit output voltage overvoltage protection; thereby reduced production cost, and had the high and sensitive advantage of protection control of overvoltage protection precision.

Description of drawings

Fig. 1 is the examples of circuits figure of conventional power source circuit;

Fig. 2 is the structure chart of the power circuit that provides of the utility model embodiment;

Fig. 3 is the examples of circuits figure of the power circuit that provides of the utility model embodiment.

Embodiment

In order to make the purpose of this utility model, technical scheme and advantage clearer,, the utility model is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.

Fig. 2 shows the structure of the power circuit that the utility model embodiment provides.

Power circuit comprises current rectifying and wave filtering circuit 100, absorption circuit 200, transforming circuit 300 and the output circuit 400 that links to each other successively; power circuit also comprises the feedback circuit 500 that is connected with output circuit 400; and respectively with current rectifying and wave filtering circuit 100, absorb the control circuit 600 that circuit 200, transforming circuit 300 are connected with feedback circuit 500; the voltage that this control circuit 600 detects transforming circuit 300 raises, and power circuit is carried out overvoltage protection.

Fig. 3 shows the examples of circuits structure of the power circuit that the utility model embodiment provides.

The structure and the annexation of current rectifying and wave filtering circuit 100, absorption circuit 200, output circuit 400 and feedback circuit 500 are the same with the conventional power source circuit, and its concrete structure repeats no more as shown in Figure 3 here.

Transforming circuit 300 comprises first primary coil, second primary coil and secondary coil, the two ends 1 of first primary coil, 2 connect absorption circuit 200, the two ends 5 of secondary coil, 6 connect output circuit 400, second end, 4 ground connection of first end, 3 connection control circuits, 600, the second primary coils of second primary coil.

Control circuit 600 comprises control chip U1, first resistance R 1, second resistance R 2, the 3rd resistance R 3, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8, second capacitor C 2, the 3rd capacitor C 3, the 4th capacitor C 4, the 5th capacitor C 5 and the second diode D2, as the utility model one embodiment, control chip U1 is the DM0270 chip, the startup leads ends Vstr of control chip U1 is by first resistance R 1 of serial connection, second resistance R 2 and the 3rd resistance R 3 connect the output of current rectifying and wave filtering circuit 100, three drain electrode end Drain of the inside integrated MOS FET pipe of control chip U1, Drain is connected with second end 2 of first primary coil that absorbs circuit 200 and transforming circuit 300 respectively together with Drain, the current peak test side 1pk of control chip U1 is by the 5th resistance R 5 ground connection, the feedback end FB of control chip U1 connects feedback circuit 500, and respectively by second capacitor C 2, the 6th resistance R 6, and the 3rd capacitor C 3 and the 5th capacitor C 5 ground connection of serial connection, the contact of the 3rd capacitor C 3 and the 5th capacitor C 5 connects first end 3 of second primary coil by the 7th resistance R 7, the power end VCC first via of control chip U1 is by the 4th capacitor C 4 ground connection, power end VCC the second tunnel is by the second diode D2 and the 8th resistance R 8 first end 3 that connects second primary coil of serial connection, the ground end GND ground connection of control chip U1.

The power end VCC of control chip U1 is connected with second primary coil of transforming circuit 300; when if power circuit the output voltage overvoltage occurs under unfavorable condition; the voltage of the power end VCC of control chip U1 also can raise, and makes control chip U1 begin to carry out overvoltage protection.

In the utility model embodiment; this power circuit is compared with the conventional power source circuit; saved the output over-voltage protection circuit; and the over-voltage protecting function that utilizes control circuit to carry is realized power circuit output voltage overvoltage protection; thereby reduced production cost, and had the high and sensitive advantage of protection control of overvoltage protection precision.

The above only is preferred embodiment of the present utility model; not in order to restriction the utility model; all any modifications of within spirit of the present utility model and principle, being done, be equal to and replace and improvement etc., all should be included within the protection range of the present utility model.

Claims

1, a kind of power circuit; it is characterized in that; described power circuit comprises current rectifying and wave filtering circuit, absorption circuit, transforming circuit and the output circuit that links to each other successively; described power circuit also comprises the feedback circuit that is connected with described output circuit; and respectively with described current rectifying and wave filtering circuit, absorb the control circuit that circuit, transforming circuit are connected with feedback circuit; the voltage that described control circuit detects transforming circuit raises, and described power circuit is carried out overvoltage protection.

2, power circuit as claimed in claim 1, it is characterized in that, described transforming circuit comprises first primary coil, second primary coil and secondary coil, the described absorption circuit of two terminations of described first primary coil, the described output circuit of two terminations of described secondary coil, the described control circuit of first termination of described second primary coil, the second end ground connection of described second primary coil.

3, power circuit as claimed in claim 2, it is characterized in that, described control circuit comprises control chip, first resistance, second resistance, the 3rd resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, second electric capacity, the 3rd electric capacity, the 4th electric capacity, the 5th electric capacity and second diode, the startup leads ends of described control chip is by first resistance of serial connection, second resistance and the 3rd resistance connect the output of described current rectifying and wave filtering circuit, three drain electrode ends of the inside integrated MOS FET pipe of described control chip are connected with second end of first primary coil of described absorption circuit and described transforming circuit respectively together, the current peak test side of described control chip is by the 5th grounding through resistance, the described feedback circuit of feedback termination of described control chip, and respectively by second electric capacity, the 6th resistance, and the 3rd electric capacity and the 5th capacity earth of serial connection, the contact of described the 3rd electric capacity and the 5th electric capacity connects first end of described second primary coil by the 7th resistance, the power end first via of described control chip is by the 4th capacity earth, described power end the second tunnel is by second diode and the 8th resistance first end that connects described second primary coil of serial connection, the ground end ground connection of described control chip.

4, power circuit as claimed in claim 3 is characterized in that, described control chip is the DM0270 chip.