CN202043051U - Half-bridge type double-pipe switching power supply - Google Patents

Abstract

The utility model discloses a half-bridge type double-pipe switching power supply, which comprises a rectification filter circuit, a double-pipe feedback oscillating and voltage stabilizing circuit, and a full-wave rectification output circuit. The power supply circuit has the characteristics of large output power, high operating efficiency, lower demand on pressure resistant value of a switch tube, small volume, light weight, long service life and the like.

Description

The two-tube Switching Power Supply of a kind of semibridge system

Technical field

The utility model relates to the two-tube switching power circuit of a kind of semibridge system.

Background technology

At present, the switching power circuit that uses generally all belongs to inverse-excitation type positive activation type single tube output switching power circuit, because the required withstand voltage of its switch triode is higher, require power bigger to it simultaneously, so the power output of its circuit rated voltage less and required switch triode is higher.

Summary of the invention

The rated voltage technical problems of high of the less and required switch triode of the power output of its circuit that the utility model exists at present switching power circuit, the utility model provides a kind of semibridge system two-tube output Switching Power Supply.

The technical solution of the utility model:

The two-tube output Switching Power Supply of a kind of semibridge system comprises current rectifying and wave filtering circuit, two-tube feedback oscillation and voltage stabilizing circuit, full-wave rectification output circuit;

Wherein: described current rectifying and wave filtering circuit comprises insurance RD, the bridge rectifier of being made up of diode D1, D2, D3, D4 and capacitor C 3, C4; Insurance RD is series at the input of bridge rectifier, and capacitor C 3, C4 are series at the output of bridge rectifier;

Described two-tube feedback oscillation and voltage stabilizing circuit comprise triode Q1, Q2, diode D5, D6, D7, D8 resistance R 1, R2, R3, R4, R5, R6, capacitor C 1, C2, C5 and transformer B1, B2; Resistance R 1 and capacitor C 1 are series at the output of bridge rectifier; Capacitor C 3 and C4 are series at the output of bridge rectifier; The collector electrode of triode Q1 connects the output head anode of bridge rectifier, and the end of the emitter connecting resistance R2 of triode, the other end of resistance R 2 are connected to the interface of resistance R 1 and capacitor C 1; The L1 winding of resistance R 5 series transformer B1, D5 is in parallel with diode, and its two ends connect the interface of base stage and resistance R 1 and the capacitor C 1 of triode Q1 respectively; The winding L 2 of transformer B1 is connected with the winding L 4 of transformer B2, respectively the interface of the interface of connecting resistance R1 and capacitor C 1 and capacitor C 3 and C4; The collector electrode connecting resistance R1 of triode Q2 and the interface of capacitor C 1, the end of emitter connecting resistance R3, the negative pole of output end of another termination bridge rectifier of R3; The winding L 3 of resistance R 6, transformer B1 is connected with capacitor C 2, and D6 is in parallel with diode, connects the negative pole of the output of the base stage of triode and bridge rectifier respectively; The L5 windings in series of diode D7, D8 and transformer B2, the base stage of a termination triode Q2, the negative pole of output end of another termination bridge rectifier; The negative pole of output end of one termination bridge rectifier of capacitor C 5, the interface of another terminating diode D7 and D8;

Described full-wave rectification output circuit comprises diode D9, D10, D11, capacitor C 6, resistance R 7; The positive pole of diode D9, D10 connects the two ends of the winding L 6 of transformer B2 respectively, and negative pole is linked together, as an output of power circuit; The centre tap end of the winding L 6 of transformer B2 is as another output of power circuit; Light-emitting diode D11 connects with resistance R 7, and is in parallel with capacitor C 6, the negative pole of one terminating diode D9, D10, the centre tap end of the winding L 6 of another termination transformer B2.

Owing to used the two-tube Switching Power Supply of semibridge system, made that the utility model Switching Power Supply power output is big, high efficiency.The switch transformer volume can be done forr a short time, has reduced the withstand voltage that requires of switching tube, because the life-span of Switching Power Supply depends primarily on the life-span of switching tube.Therefore, the utlity model has energy-efficiently, volume is little, and is in light weight, the characteristics of long service life.

Description of drawings

Fig. 1 is the circuit theory diagrams of a kind of semi-bridge switching voltage regulator of the utility model.

Embodiment

Be described further below in conjunction with 1 pair of the utility model of accompanying drawing.

Among Fig. 1, a kind of semi-bridge switching voltage regulator of the utility model, this Switching Power Supply comprises current rectifying and wave filtering circuit, two-tube feedback oscillation and voltage stabilizing circuit, full-wave rectification output circuit.Current rectifying and wave filtering circuit comprises diode D1, D2, D3, D4, capacitor C 3, C4 and insurance RD.Form bridge rectifier by D1, D2, D3, D4, capacitor C 3, C4 are filter capacitor.Civil power forms a direct voltage stably again through insurance RD on capacitor C 3, C4 after diode D1, D2, D3, D4 rectification, use for load.

Described two-tube feedback oscillation and voltage stabilizing circuit comprise triode Q1, Q2, diode D5, D6, D7, D8 resistance R 1, R2, R3, R4, R5, R6, capacitor C 1, C2, C5 and transformer B1, B2.

Wherein, two-tube feedback oscillation circuit comprises triode Q1, Q2, diode D5, D6,, resistance R 1, R2, R3, R4, R5, R6, capacitor C 1, C2, transformer B1, B2.Triode Q1 and Q2 are the symmetry output switching tube of semi-bridge switching voltage regulator.Resistance R 2 and R3 are respectively the emitter current-limiting resistance of triode Q1 and Q2.Diode D5 and D6 are respectively the emitter protection diode of triode Q1 and Q2.Resistance R 5 and R6 are respectively the base stage feedback current-limiting resistance of triode Q1 and Q2.Resistance R 1 is the collector resistance of triode Q2.Resistance R 4 is the base biasing resistor of triode Q2.Capacitor C 1 absorbs electric capacity for the high pressure reverse impulse, the safety of protection triode Q1 and Q2.Capacitor C 2 is the base stage couples back electric capacity of triode Q2.Transformer B1 is the feedback oscillation transformer, and L1, L2, three windings of L3 are arranged, and winding L 1 is the base stage feedback coil of triode Q1, and winding L 2 is the principal current primary coil, and winding L 3 is the base stage feedback coil of triode Q2.Transformer B2 is the switch output transformer, and L4, L5, three windings of L6 are arranged, and winding L 4 is the principal current primary coil, and winding L 5 is the voltage stabilizing feedback coil, and winding L 6 is the full-wave rectification output winding.Main power voltage provides the base promoter electric current by resistance R 1 and R4 for triode Q2 during startup, so in the collector loop of triode Q2, form collector current, winding L 4 and the winding L 2 of the transformer B1 collector electrode that arrive triode Q2s of the midpoint potential of filter capacitor C3 and C4 by triode B2, in winding L 2, produce an electric current, respond to through transformer B1, in winding L 1 and L3, produce an opposite polarity induced voltage of equal and opposite in direction respectively, winding L 1 is delivered to the base stage of triode Q1 to the negative polarity induced voltage by resistance R 5, and winding L 3 is delivered to the induced voltage of positive polarity the base stage of triode Q2 by resistance R 6.Produce a bigger electric current in the winding L 2 at transformer B1 after triode Q2 amplifies, in winding L1 and L3, also produce a bigger induced current, deliver to the base stage of triode Q1 and Q2 once more respectively through transformer B1 induction.The formation positive feedback so goes round and begins again.Because the winding L 1 of transformer B1 is opposite with the induced voltage equal and opposite in direction polarity among the L3, so when triode Q2 saturation conduction, triode Q1 only carries, and triode Q2 carries triode Q1 saturation conduction when ending, and finally makes triode Q1 and Q2 work in and replaces saturation conduction and carry only state.

Voltage stabilizing circuit comprises diode D7 and D8, capacitor C 5.When causing that because of line voltage is too high output voltage is too high, forming negative direct voltage through diode D8 rectification on capacitor C 5 also raises, this negative dc voltage is clamped on a lower current potential through voltage stabilizing didoe D7 with the base voltage of switching tube Q2, reduced the base voltage of triode Q2, make output voltage get back to normal value again, keep voltage stabilizing output.

The full-wave rectification output circuit comprises diode D9, D10, D11, capacitor C 6, resistance R 7.Diode D9 and D10 are the full-wave rectification diode, and capacitor C 6 is a filter capacitor, and diode D11 is an out-put supply indication light-emitting diode, and resistance R 7 is a current-limiting resistance.Replace saturation conduction and carry when ending at switching tube Q1 and Q2, the positive and negative ALT pulse electric current of also corresponding generation in the winding L 4 of transformer B2, in winding L 6, produce induced voltage through transformer B2 induction, this induced voltage forms direct voltage stably on capacitor C 6 after diode D9 and D10 full-wave rectification, output to load.

The utility model adopts the two-tube output switching power circuit of semibridge system, and inverse-excitation type positive activation type single tube output Switching Power Supply relatively has the following advantages relatively:

Semibridge system transformer switch output power of power supply is very big, and operating efficiency is very high.Because two switching tube one after the other work are equivalent to two Switching Power Supplies power output simultaneously, its power output approximates the twice of single Switching Power Supply power output.Therefore, semibridge system transformer switch output power of power supply is very big, and operating efficiency is very high, after full-wave rectification, the mains ripple coefficient S v and the current pulsation coefficient S i of output voltage are very little, only need very little filter capacitor, and it is very little that its output voltage ripple and current ripples just can reach.

The withstand voltage of the switching tube of semi-bridge switching voltage regulator is lower.Can reduce half than inverse-excitation type positive activation type single tube output Switching Power Supply to the requirement of withstand voltage of switching device to the requirement of withstand voltage of two switching devices.Because, the operating voltage of two switching devices of semi-bridge switching voltage regulator has only half of input power supply Ui, its the highest withstand voltage operating voltage and back electromotive force sum of equaling, approximately be the twice of supply voltage, this result just in time is withstand voltage half of inverse-excitation type positive activation type single tube output Switching Power Supply switching device.Therefore, semi-bridge switching voltage regulator is applicable to input voltage than higher occasion, and general line voltage is for exchanging preferably semi-bridge switching voltage regulator circuit of 220 volts of powered switch power supplys.

Because the utility model Switching Power Supply has been used the automatic voltage regulation circuit, make and under the voltage of broad, to work.

Claims (1)

1. the two-tube Switching Power Supply of semibridge system comprises current rectifying and wave filtering circuit, two-tube feedback oscillation and voltage stabilizing circuit, and the full-wave rectification output circuit is characterized in that:

Described two-tube feedback oscillation and voltage stabilizing circuit comprise triode Q1, Q2, diode D5, D6, D7, D8 resistance R 1, R2, R3, R4, R5, R6, capacitor C 1, C2, C5 and transformer B1, B2; Resistance R 1 and capacitor C 1 are series at the output of bridge rectifier; Capacitor C 3 and C4 are series at the output of bridge rectifier; The collector electrode of triode Q1 connects the output head anode of bridge rectifier, and the end of the emitter connecting resistance R2 of triode, the other end of resistance R 2 are connected to the interface of resistance R 1 and capacitor C 1; The L1 winding of resistance R 5 series transformer B1, D5 is in parallel with diode, and its two ends connect the interface of base stage and resistance R 1 and the capacitor C 1 of triode Q1 respectively; The winding L 2 of transformer B1 is connected with the winding L 4 of transformer B2, respectively the interface of the interface of connecting resistance R1 and capacitor C 1 and capacitor C 3 and C4; The collector electrode connecting resistance R1 of triode Q2 and the interface of capacitor C 1, the end of emitter connecting resistance R3, the negative pole of output end of another termination bridge rectifier of R3; The winding L 3 of resistance R 6, transformer B1 is connected with capacitor C 2, and D6 is in parallel with diode, connects the negative pole of the output of the base stage of triode and bridge rectifier respectively; The L5 windings in series of diode D7, D8 and transformer B2, the base stage of a termination triode Q2, the negative pole of output end of another termination bridge rectifier; The negative pole of output end of one termination bridge rectifier of capacitor C 5, the interface of another terminating diode D7 and D8;

Described full-wave rectification output circuit comprises diode D9, D10, D11, capacitor C 6, resistance R 7; The positive pole of diode D9, D10 connects the two ends of the winding L 6 of transformer B2 respectively, and negative pole is linked together, as an output of power circuit; The centre tap end of the winding L 6 of transformer B2 is as another output of power circuit; Light-emitting diode D11 connects with resistance R 7, and is in parallel with capacitor C 6, the negative pole of one terminating diode D9, D10, the centre tap end of the winding L 6 of another termination transformer B2.

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