CN2360878Y

CN2360878Y - D. C. voltage stabilizing power source

Info

Publication number: CN2360878Y
Application number: CN 98207765
Authority: CN
Inventors: 黄虎钧
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-10
Filing date: 1998-08-10
Publication date: 2000-01-26
Anticipated expiration: 2008-08-10

Abstract

The utility model discloses a DC voltage stabilizing power source. The utility model is characterized in that the utility model comprises a power source filter rectifying circuit, a square-wave output circuit mainly composed of a pulse width modulation chip UC 3844 and a field effect transistor, the pulse width of the square-wave output circuit can be controlled, a step-down transformer, an output rectifying circuit, a power source indicating light circuit, an output filter circuit, a pulse width control circuit and an output voltage control circuit. The utility model has the advantages of small ripple coefficient of output voltage, good voltage stabilizing performance, strong adaptability of power supply fluctuation and load change, small size, small quantity of elements, light weight, etc. and the utility model is especially suitable for electric equipment, such as a portable computer, etc.

Description

D.C. regulated power supply

The utility model relates to the D.C. regulated power supply that a kind of portable computer uses.

The D.C. regulated power supply ubiquity of portable computer use at present the shortcoming that employed components and parts are many, volume is big, deal is heavy.

The D.C. regulated power supply that the purpose of this utility model is to provide a kind of components and parts of use few, volume is little, deal is light.

Of the present utility model being characterised in that: it contains power filter rectification circuit (1), by input pin 11,10 through capacitor C 4, the pulse width modulating chip U1 that the charge-discharge circuit that resistance R 8-R10 constitutes links to each other with the power filter rectification circuit output end and input end are the controlled square wave output circuit (2) of pulsewidth of leading formation through the field effect transistor Q1 that the output pin 8 of resistance R 2 and pulse width modulating chip U1 links to each other, the voltage conversion circuit (3) that step-down transformer TR1 that former limit links to each other with the output terminal of field effect transistor Q1 constitutes, by anodal link to each other with the secondary output terminal of step-down transformer TR1 and and be connected to the commutation diode D3 of the capacitor C 8 of mutual serial connection and resistance R 13 and the output rectification circuit (4) that capacitor C 10 is constituted that joins with commutation diode D3 negative pole, be connected in series the power light circuit (5) that forms by LED 1 and resistance R 14 between the negative pole that is connected to commutation diode D3 and the ground, be connected to negative pole and the output filter circuit between the ground (6) of commutation diode D3, by an end through diode D2 link to each other with the input pin 10 of pulse width modulating chip U1 and the other end and pulse width modulating chip U1 lower margin 9 is connect altogether surging over the ground absorb electric capacity ZV1 step-down transformer TR1 pay the limit inductive coil and directly cross-over connection link to each other and the control pin 3 of output terminal and pulse width modulating chip U1 and serve as the output voltage controlling circuit (8) of master's formation in the input pin 10 of pulse width modulating chip U1 and the pulse width control circuit (7) that the charge and discharge capacitance C3 between the lower margin 9 is constituted and with the output terminal of the output rectification circuit after input end and the current limliting to the photoelectrical coupler U2 that lower margin 9 joins.That described pulse width modulating chip U1 uses is chip UC3844.

Use proof: it has reached intended purposes.

In order in conjunction with the embodiments the utility model to be done detailed describing below, show as follows present specification used accompanying drawing number and title brief introduction:

Fig. 1: the schematic block circuit diagram of D.C. regulated power supply;

Fig. 2: the circuit theory diagrams of D.C. regulated power supply.

Embodiment: VAC exchanges input, and 85V-265V, VDC are DC voltage-stabilizing output, according to the parameter difference, can select for use between 10V-20V, and output current is 2.2A.

Ask for an interview accompanying drawing.The 1st, the power filter rectification circuit, it is by the LC filter, full wave rectifier BR1 and the power filtering capacitor C2 that form with electric capacity C1, inductance L 1 serial connection of serial connection constitute mutually successively.The 2nd, the square wave output circuit that pulsewidth is controlled, charge and discharge capacitance C4, C3 can be respectively applied for the input signal that remedies pulse width modulating chip U1, pulsewidth feedback control signal amplitude at short notice and descend, stable with the input voltage of the input pin 11,10 of keeping pulse width modulating chip U1.The 3rd, the voltage conversion circuit that step-down transformer TR1 constitutes, its former limit has also connect one and is connected in series the revers voltage that prevents that forms mutually by stabilivolt ZD1 and backward dioded D1 and punctures branch road.The 4th, output rectification circuit, what commutation diode D3 used is the F5KQ60 type.The 5th, the power light circuit, at power supply just often, LED 1 is bright, makes photoelectrical coupler U2 conducting.The 6th, output filter circuit is connected in series mutually with ground capacitance C11 by inductance L 2 and forms.The 7th, pulse width control circuit, the diode D2 of forward sense electromotive force through just connecing of its pair limit inductive coil raises the current potential of pulse width modulating chip U1 input pin 10 when the input voltage on the former limit of step-down transformer TR1 descends, play the negative feedback control action, improved the ripple negative of output voltage, improved adaptability mains fluctuations.The 8th, output voltage controlling circuit, it is linked to each other and the photoelectrical coupler U2 of the controllable silicon U3 of negative pole reversal connection of photodiode through the output terminal of resistance R 11 and output rectification circuit by the positive pole of output terminal and the control pin 3 of pulse width modulating chip U1 photodiode of input end with lower margin 9 is linked to each other, link to each other and variable resistor UR1 that its other end links to each other with the control end of controllable silicon U3 by the output terminal of movable end and output rectification circuit, its other end constitutes in the negative pole of controllable silicon U3 and the capacitor C 9 of the effect that discharges and recharges when output voltage fluctuates between the resistor voltage divider circuit mid point with electric resistance partial pressure branch road and cross-over connection that the resistance R 11 that the positive pole of controllable silicon U3 links to each other composes in series mutually.That wherein, photoelectric coupling circuit U2 uses is PC817.That controllable silicon U3 uses is TL431.When load increase or supply voltage decline, the output voltage of D.C. regulated power supply descends, in case LED 1 goes out, photoelectrical coupler U2 just ends, and its output terminal is just controlled pulse width modulating chip U1, and the limit output voltage of paying of step-down transformer TR1 is risen; Reduce or supply voltage when rising in load, the output voltage of D.C. regulated power supply just raises, in case make controllable silicon U3 conducting, photoelectrical coupler U2 just transships, and its output terminal is just controlled pulse width modulating chip U1, and the limit output voltage of paying of step-down transformer TR1 is descended.So, just guaranteed the dynamic stability of D.C. regulated power supply output voltage.Variable resistor UR1 is used for adjusting in advance controllable silicon U3 control end voltage and uses, and in this example, that field effect transistor Q1 uses is K1507.In addition, in Fig. 2, S1, S2 are respectively the connection terminals of power supply and output voltage, and FUSE1 is a fuse.

So this D.C. regulated power supply just can be kept the dynamic stability of its output voltage under the condition of using less element, and it is fast to regulate the speed, the output voltage ripple coefficient might as well, be applicable to very that portable computer etc. is many to require the power supply unit quality to get well but volume is little, weight is wanted to use under the light situation.

Claims

1. D.C. regulated power supply, contain filtering, rectification and output voltage controlling circuit, it is characterized in that: it contains power filter rectification circuit (1), by input pin 11,10 through capacitor C 4, the pulse width modulating chip U1 that the charge-discharge circuit that resistance R 8-R10 constitutes links to each other with the power filter rectification circuit output end and input end are the controlled square wave output circuit (2) of pulsewidth of leading formation through the field effect transistor Q1 that the output pin 8 of resistance R 2 and pulse width modulating chip U1 links to each other, the voltage conversion circuit (3) that step-down transformer TR1 that former limit links to each other with the output terminal of field effect transistor Q1 constitutes, by anodal link to each other with the secondary output terminal of step-down transformer TR1 and and be connected to the commutation diode D3 of the capacitor C 8 of mutual serial connection and resistance R 13 and the output rectification circuit (4) that capacitor C 10 is constituted that joins with commutation diode D3 negative pole, be connected in series the power light circuit (5) that forms by LED 1 and resistance R 14 between the negative pole that is connected to commutation diode D3 and the ground, be connected to negative pole and the output filter circuit between the ground (6) of commutation diode D3, by an end through diode D2 link to each other with the input pin 10 of pulse width modulating chip U1 and the other end and pulse width modulating chip U1 lower margin 9 is connect altogether surging over the ground absorb electric capacity ZV1 step-down transformer TR1 pay the limit inductive coil and directly cross-over connection link to each other and the control pin 3 of output terminal and pulse width modulating chip U1 and serve as the output voltage controlling circuit (8) of master's formation in the input pin 10 of pulse width modulating chip U1 and the pulse width control circuit (7) that the charge and discharge capacitance C3 between the lower margin 9 is constituted and with the output terminal of the output rectification circuit after input end and the current limliting to the photoelectrical coupler U2 that lower margin 9 joins.

2. D.C. regulated power supply according to claim 1 is characterized in that: that described pulse width modulating chip U1 uses is chip UC3844.

3. D.C. regulated power supply according to claim 1 is characterized in that: described power filter rectification circuit (1) is by the LC filter, full wave rectifier BR1 and the power filtering capacitor C2 that constitute with electric capacity C1, inductance L 1 of serial connection constitute mutually successively.

4. D.C. regulated power supply according to claim 1 is characterized in that: the former limit of described step-down transformer TR1 can and connect one and is connected in series the revers voltage that prevents that forms mutually by stabilivolt ZD1 and backward dioded D1 and punctures branch road.

5. D.C. regulated power supply according to claim 1 is characterized in that: described output filter circuit (6) is formed by inductance L 2, ground capacitance C11 serial connection.

6. D.C. regulated power supply according to claim 1 is characterized in that: described output voltage controlling circuit (8) is linked to each other and the photoelectrical coupler U2 of the controllable silicon U3 of negative pole reversal connection of photodiode through the output terminal of resistance R 11 and output rectification circuit by the positive pole of output terminal and the control pin 3 of pulse width modulating chip U1 photodiode of input end with lower margin 9 is linked to each other, link to each other with the output terminal of output rectification circuit and variable resistor UR1 that its other end links to each other with the control end of controllable silicon U3 by movable end, the resistance R 12 that the other end links to each other with the positive pole of controllable silicon U3 is in series the electric resistance partial pressure branch road formed and cross-over connection in the negative pole and 9 formations of the capacitor C between the electric resistance partial pressure branch road mid point of controllable silicon U3.

7. D.C. regulated power supply according to claim 1 is characterized in that: the PC817 type that described photoelectrical coupler U2 is a usefulness.