CN201422076Y

CN201422076Y - Booster circuit

Info

Publication number: CN201422076Y
Application number: CN2009200542796U
Authority: CN
Inventors: 邹曙; 梁远文
Original assignee: Dongguan Guanjia Electronic Equipment Co Ltd
Current assignee: Dongguan Guanjia Electronic Equipment Co Ltd
Priority date: 2009-04-10
Filing date: 2009-04-10
Publication date: 2010-03-10
Anticipated expiration: 2019-04-10

Abstract

The utility model relates to voltage conversion circuit technical field, in particular to a booster circuit which comprises a coupling inductor L, a switch power tube Q1, rectifier diodes D1, D2 and output filter capacitors C1 and C2; the first pin of the inductor L is connected with the positive electrode of the voltage input end, the second pin is connected with the anode of the D1, the third pin is connected with the anode of the D2, the fourth pin is connected with the negative electrode of the C2; the first pin of the Q1 is connected with the drive signal end, the second pin is connectedwith the anode of the D1, the third pin is connected with the negative electrode of the voltage input end; the cathode of the D1 is connected with the positive electrode of the C1, the negative electrode of the C1 is connected with the negative electrode of the voltage input end, the cathode of the D2 is connected with the positive electrode of the C2; the positive electrode of the C1 is connectedwith the negative electrode of the C2; and the positive electrode of the C2 is the positive electrode of the voltage output end and the negative electrode of the C1 is the negative electrode of the voltage output end; the booster circuit not only maintains the high step-up ratio of a Flyback circuit, but also has the characteristic of wider input voltage range.

Description

A kind of booster circuit

Technical field:

The utility model relates to the voltage conversion circuit technical field, relates in particular to a kind of booster circuit.

Background technology:

In the energy recovering type ageing system, booster circuits such as BOOST (boosting) circuit or Flyback (flyback) circuit need be set usually, be used for low-voltages such as 3.3V, the 5V of PC (PC) power supply output, 12V are raised to 48V, to realize the recovery of the energy.Wherein, BOOST circuit in the ageing system is generally does not isolate the BOOST booster circuit, as Fig. 1, it mainly is made up of switching power tube Q101, inductance L 101, rectifier diode D101, filter capacitor C101, this booster circuit step-up ratio in theory can be very big, but because actual duty cycle must be less than 90%, otherwise conversion efficiency will be very low, so the actual step-up ratio of this booster circuit can not surpass 10 times, step-up ratio is lower.So, some producer is in order to improve step-up ratio, adopted the booster circuit of the Flyback circuit of high step-up ratio as ageing system, as Fig. 2, it mainly is made up of transformer T, switching power tube Q201, rectifier diode D201, filter capacitor C201, though this kind circuit can be realized high step-up ratio by the no-load voltage ratio of transformer T, but because transformer T has leakage inductance, make switching power tube Q201 have the high problem of voltage stress, so the scope of Flyback circuit input voltage often can only be rated voltage+/-50%, promptly the scope of input voltage is narrower.

The utility model content:

The purpose of this utility model is exactly the booster circuit that a kind of high step-up ratio, input voltage range broad are provided at the deficiency of prior art existence.

To achieve these goals, the technical solution adopted in the utility model is:

It comprises coupling inductance L, switching power tube Q1, rectifier diode D1, D2, output filter capacitor C1, C2; The 1st pin of described coupling inductance L is connected with the positive pole of voltage input end, and the 2nd pin is connected with the anode of rectifier diode D1, and the 3rd pin is connected with the anode of rectifier diode D2, and the 4th pin is connected with the negative pole of output filter capacitor C2; The 1st pin of described switching power tube Q1 is connected with the drive signal end, and the 2nd pin is connected with the anode of rectifier diode D1, and the 3rd pin is connected with the negative pole of voltage input end; The negative electrode of rectifier diode D1 is connected with the positive pole of output filter capacitor C1, and the negative pole of output filter capacitor C1 is connected with the negative pole of voltage input end, and the negative electrode of rectifier diode D2 is connected with the positive pole of output filter capacitor C2; The positive pole of output filter capacitor C1 is connected with the negative pole of C2; The positive pole of the just very voltage output end of output filter capacitor C2, the negative pole of output filter capacitor C1 are the negative pole of voltage output end.

Described coupling inductance L is made up of inductance L 1 and inductance L 2, and L1 is the former limit of coupling inductance L, and L2 is the secondary of coupling inductance L.

The utility model beneficial effect is:

A kind of booster circuit that the utility model provides has adopted the BOOST circuit of band coupling inductance L, and BOOST circuit and Flyback circuit combined, when producing, as long as the turn ratio by designing suitable coupling inductance L, regulate duty ratio automatically, output voltage stabilization is at 48V in the time of can being implemented in the input voltage of broad; Therefore, the utility model has not only kept the characteristics of the high step-up ratio of Flyback circuit, and has the characteristics of input voltage range broad.

Description of drawings:

Fig. 1 is the circuit theory diagrams of prior art BOOST circuit;

Fig. 2 is the circuit theory diagrams of prior art Flyback circuit;

Fig. 3 is circuit theory diagrams of the present utility model.

Embodiment:

Below in conjunction with accompanying drawing the utility model is further described, please refer to Fig. 3, the utility model comprises coupling inductance L, switching power tube Q1, rectifier diode D1, D2, output filter capacitor C1, C2; The 1st pin of described coupling inductance L is connected with the positive pole of voltage input end, and the 2nd pin is connected with the anode of rectifier diode D1, and the 3rd pin is connected with the anode of rectifier diode D2, and the 4th pin is connected with the negative pole of output filter capacitor C2; The 1st pin of described switching power tube Q1 is connected with the drive signal end, and the 2nd pin is connected with the anode of rectifier diode D1, and the 3rd pin is connected with the negative pole of voltage input end; The negative electrode of rectifier diode D1 is connected with the positive pole of output filter capacitor C1, and the negative pole of output filter capacitor C1 is connected with the negative pole of voltage input end, and the negative electrode of rectifier diode D2 is connected with the positive pole of output filter capacitor C2; The positive pole of output filter capacitor C1 is connected with the negative pole of C2; The positive pole of the just very voltage output end of output filter capacitor C2, the negative pole of output filter capacitor C1 are the negative pole of voltage output end, and load RL is serially connected between the positive pole and negative pole of voltage output end.

Described coupling inductance L is made up of inductance L 1 and inductance L 2, and L1 is the former limit of coupling inductance L, and the number of turn is N1, L2 is the secondary of coupling inductance L, and the number of turn is N2, and D1 is a former limit rectifier diode, C1 is a former limit output filter capacitor, and D2 is the secondary rectifier diode, and C2 is the secondary output filter capacitor.

Wherein, the no-load voltage ratio (Vout/Vin) of the utility model input voltage vin and output voltage V out, the derivation of the relation of the duty ratio D (Ton/Ton+Toff) of the switching tube drive signal DRV1 of itself and drive signal end is as follows:

If the magnetizing inductance of coupling inductance L is Lm, then during the Ton, the Q1 conducting, D1 and D2 bear reverse voltage and end, and input voltage vin is added on the magnetizing inductance Lm, and then during the Ton, the voltagesecond product on the Lm is Vin*Ton; During the Toff, Q1 turn-offs, and D1 and D2 bear forward voltage and conducting, and the voltage on the magnetizing inductance Lm is Vc1-Vin at this moment, and wherein Vc1 is the voltage on the C1, and then the voltagesecond product on the Lm is (Vc1-Vin) * Toff during the Toff.According to the voltagesecond product balance principle, Vin*Ton=(Vc1-Vin) * Toff, then Vc1=Vin/ (1-D).During the Toff, the voltage Vc2 of C2 equals the voltage of coupling inductance secondary L2, promptly

VL2=(N2/N1) * VL1=(N2/N1) * (Vc1-Vin)=(N2/N1) * D*Vin/ (1-D), output voltage V out=Vc1+Vc2=(N2/N1) * D*Vin/ (1-D)+Vin/ (1-D) so,

So, can draw Vout/Vin=[1+ (N2/N1) * D]/(1-D).

From above-mentioned derivation as can be known, the utility model is when producing, as long as the turn ratio by designing suitable coupling inductance L, regulate duty ratio automatically, output voltage stabilization is at 48V in the time of can being implemented in the input voltage of broad; Therefore, the utility model has not only kept the characteristics of the high step-up ratio of Flyback circuit, and has the characteristics of input voltage range broad.

Certainly, the above only is preferred embodiment of the present utility model, so all equivalences of doing according to the described structure of the utility model patent claim, feature and principle change or modify, is included in the utility model patent claim.

Claims

1, a kind of booster circuit is characterized in that: it comprises coupling inductance L, switching power tube Q1, rectifier diode D1, D2, output filter capacitor C1, C2; The 1st pin of described coupling inductance L is connected with the positive pole of voltage input end, and the 2nd pin is connected with the anode of rectifier diode D1, and the 3rd pin is connected with the anode of rectifier diode D2, and the 4th pin is connected with the negative pole of output filter capacitor C2; The 1st pin of described switching power tube Q1 is connected with the drive signal end, and the 2nd pin is connected with the anode of rectifier diode D1, and the 3rd pin is connected with the negative pole of voltage input end; The negative electrode of rectifier diode D1 is connected with the positive pole of output filter capacitor C1, and the negative pole of output filter capacitor C1 is connected with the negative pole of voltage input end, and the negative electrode of rectifier diode D2 is connected with the positive pole of output filter capacitor C2; The positive pole of output filter capacitor C1 is connected with the negative pole of C2; The positive pole of the just very voltage output end of output filter capacitor C2, the negative pole of output filter capacitor C1 are the negative pole of voltage output end.

2, a kind of booster circuit according to claim 1 is characterized in that: described coupling inductance L is made up of inductance L 1 and inductance L 2, and L1 is the former limit of coupling inductance L, and L2 is the secondary of coupling inductance L.