CN201075825Y

CN201075825Y - Impulse magnetic-controlled switch supply power

Info

Publication number: CN201075825Y
Application number: CNU2007202002952U
Authority: CN
Inventors: 周原
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-24
Filing date: 2007-04-24
Publication date: 2008-06-18
Anticipated expiration: 2017-04-24

Abstract

The utility model discloses a pulse by pulse magnetic control switch source the structure of which includes a self-excitation half bridge switch source circuit. The utility model is characterized in that the structure also includes a switch pulse width control circuit. The utility model controls the pulse width of the switch by controlling a transformer winding so as to control the voltage or current that is outputted. The switch pulse width control circuit of the utility model carries through control on the secondary output pulses of an output transformer (T2) one by one; therefore, the control precision is high and response speed is fast. Furthermore, the utility model has simple control structure and only uses few universal electric elements; thereby having low power consumption, small volume and low implement cost. The utility model has the advantages of high control precision, fast response speed, high circuit efficiency, low power consumption, small volume and low implement cost. The utility model can be taken as a middle-small power source and applied to the products which have higher requirements for power and volume like a charger, an adapter and a lighting fitting, etc.

Description

A kind of Pulse by Pulse magnetic switch power supply

Technical field

The utility model relates to a kind of power supply, particularly a kind of Pulse by Pulse magnetic switch power supply.

Background technology

At present, in household appliances such as charger, adapter, lighting, it is many that the self-excited half-bridge switch power source of middle low power is used.The type of self-excited half-bridge switch power source mainly is divided into two classes.One class belongs to the open loop power supply, i.e. the power supply that can not control effectively to output voltage or electric current; Another kind of self-excited half-bridge switch power source has added integrated package in circuit, constitute closed-loop control.Though can stablize the voltage or the electric current of output, make the complex structure of this type of power circuit like this, the manufacturing cost of power supply product is higher.

Summary of the invention

The purpose of this utility model is: a kind of Pulse by Pulse magnetic switch power supply is provided.This Pulse by Pulse magnetic switch power supply can be realized the voltage stabilizing or the current stabilization of power supply output, and has control precision height, simple in structure, characteristics that implementation cost is low.

The utility model is to constitute like this, and its formation comprises the self-excited half-bridge switch power source circuit, and characteristics are that formation also comprises a switching pulse width control circuit.

Above-mentioned Pulse by Pulse magnetic switch power supply, described switching pulse width control circuit formation comprises: the error detection unit that is connected on the self-excited half-bridge switch power source circuit output end, with the error signal processing unit that error detection unit output is joined, export the pulse control unit that joins and pulse-width-modulating signal is provided for the self-excited half-bridge switch power source circuit with the error signal processing unit.

Above-mentioned Pulse by Pulse magnetic switch power supply, described pulse control unit is made up of control triode Q1, diode D1, diode D2, control winding N1; Described error signal processing unit is made up of error amplifying triode Q2, capacitor C 1, diode D3, resistance R 1; Described error detection unit is made up of resistance R 4, R5 and voltage stabilizing didoe D7; Oppositely diode D2 that connects and diode D1 are serially connected on the collector electrode of control triode Q1, the negative pole of diode D2 links to each other with the positive pole of output Vout+ end diode in series D4, is wound in switching pulse control winding N1 on the control transformer T1 and is connected to the positive pole of diode D2 and controls between the emitter of triode Q1; The emitting stage of error amplifying triode Q2 joins with output Vout+ end, the base stage of error amplifying triode Q2 is joined with output Vout+ end through resistance R 5 and resistance R 4, voltage stabilizing didoe D7 is connected between the node of output Vout end and resistance R 4 and resistance R 5, the collector electrode of error amplifying triode Q2 joins through resistance R 1 and the base stage of control triode Q1, capacitor C 1 is connected between the negative pole of the base stage of control triode Q1 and diode D2, and the emitter of control triode Q1 links to each other with output Vout end through diode D3.

Compared with prior art, the utility model is by control transformer winding control switch pulse duration, thus the voltage or the electric current of realization control output.Switching pulse width control circuit of the present utility model is one by one the switching pulse of T2 level output of output transformer to be controlled, so control precision is very high, response speed is fast.Besides, the utility model control structure is simple, only uses a small amount of general electronic component, so low in energy consumption, volume is little, implementation cost is low.The utlity model has that control precision is very high, response speed is fast, circuit efficiency is high, low in energy consumption, volume is little, the low characteristics of implementation cost.Can be used as the middle low power power supply, be applied in the product that charger, adapter, lighting etc. have relatively high expectations to power to volume ratio.

Description of drawings

Accompanying drawing 1 is circuit theory diagrams of the present utility model.

Embodiment

Embodiment.Pulse by Pulse magnetic switch power supply constitutes as shown in Figure 1.Its formation comprises existing self-excited half-bridge switch power source circuit, and characteristics are that formation also comprises a switching pulse width control circuit.Described switching pulse width control circuit formation comprises: the error detection unit that is connected on the self-excited half-bridge switch power source circuit output end, with the error signal processing unit that signal amplification, time-delay, reset function are arranged that error detection unit output is joined, export the pulse control unit that joins and pulse-width-modulating signal is provided for the self-excited half-bridge switch power source circuit with the error signal processing unit.Wherein, described pulse control unit is made up of NPN type control triode Q1, diode D1, diode D2, control winding N1; Described error signal processing unit is made up of positive-negative-positive error amplifying triode Q2, capacitor C 1, diode D3, resistance R 1; Described error detection unit is made up of resistance R 4, R5 and voltage stabilizing didoe D7; The diode D1 that the reverse diode D2 that connects is connected with forward is serially connected on the collector electrode of control triode Q1, oppositely the negative pole of the diode D2 that connects links to each other with the positive pole of the reverse diode D4 that is connected of output Vout+ end series connection, is wound between switching pulse control winding N1 on the control transformer T1 positive pole that is connected to diode D2 and the emitter of controlling triode Q1; The emitting stage of error amplifying triode Q2 joins with output Vout+ end, the base stage of error amplifying triode Q2 is joined with output Vout+ end through resistance R 5 and resistance R 4, oppositely the voltage stabilizing didoe D7 that connects is connected between the node of output Vout end and resistance R 4 and resistance R 5, the collector electrode of error amplifying triode Q2 joins through resistance R 1 and the base stage of control triode Q1, capacitor C 1 is connected between the negative pole of the base stage of control triode Q1 and diode D2, and the emitter of control triode Q1 links to each other with output Vout end through the diode D3 that forward connects.

When input voltage vin reaches operating voltage, start-up circuit produces the base stage that a starting impulse is added to half-bridge power pipe Q3, because the positive feedback effect of T1 causes half-bridge to produce self-oscillation, output transformer T2 level voltage pulse output also begins by rectifying tube D4 output filter capacitor C3 to be charged; When the conducting of half-bridge positive power tube, T2 level output positive pulse, this positive pulse is carried out reverse charging through C1, Q1be knot, D3 to C1; When output voltage or current value reach the detection voltage of setting or current value, voltage stabilizing didoe D7 punctures, error signal is transferred to Q2 through R5 and carries out the error amplification, and error signal puts on the delay circuit of resistance R 1, C1 composition after error amplifier tube Q2 amplifies; When T2 level output negative pulse, because C1 reverse charging, this moment, Q1 will conducting after a period of time, and this time length is controlled by the error feedback signal delay time; When C1 was charged to certain value, error signal made the Q1 conducting through R1, Q1 be knot, N1, D2, and the N1 winding voltage with control transformer T1 is reduced to below the 1V simultaneously, and the anti-phase power tube of half-bridge is forced closed, and pulse duration is compressed; After the anti-phase power tube of half-bridge is closed fully, the counter-rotating of the induced voltage of control transformer T1 winding, oxide-semiconductor control transistors Q1 ends, and this moment, half-bridge positive power tube was driven conducting by T1, and output transformer T2 exports positive pulse, and so far a pulse Control Circulation is finished.Because the effect of partiting dc capacitor C2, have only alternating component be added in output transformer elementary on, because of negative pulse narrows down, the amplitude of positive pulse will reduce in proportion, after rectification, output voltage descends, thereby has realized complete power supply closed-loop control.

Claims

1. Pulse by Pulse magnetic switch power supply, its formation comprises the self-excited half-bridge switch power source circuit, it is characterized in that, constitutes also to comprise a switching pulse width control circuit.

2. Pulse by Pulse magnetic switch power supply according to claim 1, it is characterized in that, described switching pulse width control circuit formation comprises: the error detection unit that is connected on the self-excited half-bridge switch power source circuit output end, with the error signal processing unit that error detection unit output is joined, export the pulse control unit that joins and pulse-width-modulating signal is provided for the self-excited half-bridge switch power source circuit with the error signal processing unit.

3. Pulse by Pulse magnetic switch power supply according to claim 2 is characterized in that, described pulse control unit is made up of control triode (Q1), diode (D1), diode (D2), control winding (N1); Described error signal processing unit is made up of error amplifying triode (Q2), electric capacity (C1), diode (D3), resistance (R1); Described error detection unit is made up of resistance (R4), (R5) and voltage stabilizing didoe (D7); Oppositely diode (D2) that connects and diode (D1) are serially connected on the collector electrode of control triode (Q1), the negative pole of diode (D2) links to each other with the positive pole of output Vout+ end diode in series (D4), is wound in switching pulse control winding (N1) on the control transformer (T1) and is connected to the positive pole of diode (D2) and controls between the emitter of triode (Q1); The emitting stage of error amplifying triode (Q2) joins with output Vout+ end, the base stage of error amplifying triode (Q2) is joined with output Vout+ end through resistance (R5) and resistance (R4), voltage stabilizing didoe (D7) is connected between the node of output Vout-end and resistance (R4) and resistance (R5), the collector electrode of error amplifying triode (Q2) joins through the resistance (R1) and the base stage of control triode (Q1), electric capacity (C1) is connected between the base stage and the negative pole of diode (D2) of control triode (Q1), and the emitter of control triode (Q1) links to each other with output Vout-end through diode (D3).