CN201623630U - Voltage-reducing circuit of switch power supply - Google Patents
Voltage-reducing circuit of switch power supply Download PDFInfo
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- CN201623630U CN201623630U CN2010201549136U CN201020154913U CN201623630U CN 201623630 U CN201623630 U CN 201623630U CN 2010201549136 U CN2010201549136 U CN 2010201549136U CN 201020154913 U CN201020154913 U CN 201020154913U CN 201623630 U CN201623630 U CN 201623630U
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Abstract
The utility model relates to a voltage-reducing circuit of a switch power supply. The traditional voltage-reducing circuit is easy to generate great current pulse under the condition that the voltage difference is overlarge to damage the stability of a system. The voltage-reducing circuit comprises a front-stage current filter circuit, a first-stage voltage-reducing circuit, a diode D, a second-stage voltage-reducing circuit and two feedback circuits; one end of the front-stage current filter circuit is connected with an anode of direct current input voltage; one end of the first-stage voltage-reducing circuit, which is connected with one feedback circuit in parallel, is connected with the other end of the front-stage filter circuit; the other end of the parallelly-connected front-stage voltage-reducing circuit is connected with an anode of the diode D; one end of the second-stage voltage-reducing circuit, which is connected with the other feedback circuit in parallel, is connected with a cathode of the diode D; and the other end of the parallelly-connected second-stage voltage-reducing circuit is used as a voltage output end; and two feedback circuits adopt a completely-same circuit structure. By using the two stages to continuously reduce the voltage, the utility model breaks through the barrier of overlarge voltage difference and can reduce the voltage of high-voltage direct current voltage stably, efficiently, accurately and safely.
Description
Technical field
The utility model belongs to electronic technology field, relates to a kind of Switching Power Supply reduction voltage circuit, be applicable to that input voltage is bigger, input and output pressure reduction than higher, load power big, to the stability of system with transform required precision than higher voltage dropping power supply.
Background technology
At present, the direct current high power switching power supply product of pressing during state's inner high voltage changes is very few, and this class power supply is mainly used in the step-down of energy after remote non-relay transmission and handles, to drive the operate as normal of other equipment.In order to reduce the energy loss in the transmission course, require transmission voltage very big, therefore this type of reduction voltage circuit need have characteristics such as input and output pressure reduction is big, transformation efficiency height, simultaneously in order to guarantee the trouble free service of whole system, need this type of power supply to have high stability, should collaborative work between the various piece, need under the situation of other parts accidental damage, independently bear transformation task again.The method of existing increase power-supply system reliability generally is the power supply parallel technology, stablizes on the basis of load-sharing electric current and the realization of parallel technology mainly is based upon individual module, i.e. flow equalize technology.Parallel current-sharing method commonly used is to be used for the chip of current-sharing or to use flow equalizing circuit to realize in module-external in the inside modules interpolation, low precision, and the circuit complexity, the cost height, efficient is low.Problems such as and present state-of-the-art parallel current-sharing scheme is to use the voltage control loop, and the output voltage of power module is fed back to the power module control circuit, and this type of circuit still exists output voltage to change greatly, and stability is not enough.Simultaneously, existing step-down module is easy to generate very big current impulse under the excessive situation of pressure reduction, destroys the stability of system.
Summary of the invention
The purpose of this utility model is at the deficiencies in the prior art, and a kind of voltage reduction circuits of high power switching power supply is provided.
The utility model comprises prime current filtering circuit, one-level reduction voltage circuit, diode D, secondary reduction voltage circuit and two feedback circuits.One end of prime current filtering circuit is connected with the positive pole of DC input voitage, and the end after one-level reduction voltage circuit and the feedback circuit parallel connection is connected with the other end of prime current filtering circuit, and the other end after the parallel connection is connected with the anode of diode D; End after secondary reduction voltage circuit and another feedback circuit parallel connection is connected with the negative electrode of diode D, and the other end is as voltage output end; Two feedback circuits adopt identical circuit structure.The utility model physical circuit is as follows:
Prime current filtering circuit comprises prime filter inductance L41, the first filter capacitor C41, the second filter capacitor C42, the 3rd filter capacitor C43.The end of filter inductance L41 is connected with the positive pole of DC input voitage, negativing ending grounding after the prime first filter capacitor C41, the prime second filter capacitor C42 and prime the 3rd filter capacitor C43 series connection, the anode after the series connection is connected with the other end of prime filter inductance L41.
The one-level reduction voltage circuit comprises one-level insulated gate bipolar transistor Q11, one-level backward diode D11, one-level sustained diode 12, one-level energy storage inductor L11, one-level filter inductance L12, the one-level first filter capacitor C11, the one-level second filter capacitor C12, one-level the 3rd filter capacitor C13, one-level the 4th filter capacitor C14.The negative electrode of one-level backward diode D11 is connected with the collector electrode of one-level insulated gate bipolar transistor Q11 and the other end of prime filter inductance L41, the end of the anode of one-level backward diode D11, the negative electrode of one-level sustained diode 12, one-level energy storage inductor L11 all is connected the plus earth of one-level sustained diode 12 with the emitter of one-level insulated gate bipolar transistor Q11; Anode after the one-level first filter capacitor C11 and the one-level second filter capacitor C12 series connection is connected the negativing ending grounding after the series connection with the other end of one-level energy storage inductor L11 and the end of one-level filter inductance L12; Anode after one-level the 3rd filter capacitor C13 and one-level the 4th filter capacitor C14 series connection is connected the negativing ending grounding after the series connection with the other end of one-level filter inductance L12 and the anode of diode D.
The secondary reduction voltage circuit comprises secondary insulated gate bipolar transistor Q21, secondary backward diode D21, secondary sustained diode 22, secondary energy storage inductor L21, secondary filter inductance L22, the secondary first filter capacitor C21, the secondary second filter capacitor C22.The negative electrode of secondary backward diode D21 is connected with the collector electrode of secondary insulated gate bipolar transistor Q21 and the negative electrode of diode D connects, the end of the anode of secondary backward diode D21, the negative electrode of secondary sustained diode 22, secondary energy storage inductor L21 all is connected the plus earth of secondary sustained diode 22 with the emitter of secondary insulated gate bipolar transistor Q21; The end of the anode of the secondary first filter capacitor C21, secondary filter inductance L22 is connected with the other end of secondary energy storage inductor L21, the negativing ending grounding of the secondary first filter capacitor C21; The anode of the secondary second filter capacitor C22 is connected with the other end of secondary filter inductance L22, as voltage output end, and the negativing ending grounding of the secondary second filter capacitor C22.
Feedback circuit comprises that Temperature Feedback regulating circuit, voltage sampling circuit, PWM produce circuit, IGBT drive circuit, the auxiliary feedback regulating circuit of output voltage.
Described Temperature Feedback regulating circuit comprises thermistor RT1, the first potentiometer RP1, the first operational amplifier U1, the first metal-oxide-semiconductor field effect transistor Q311, the first divider resistance R311, the first pull-up resistor R312, the first feedback filtering capacitor C 311, the second feedback filtering capacitor C 312.Thermistor RT1 is placed on the circuit board of one-level reduction voltage circuit 1 or secondary reduction voltage circuit 2, one termination of thermistor RT1+15V accessory power supply, end after the first divider resistance R311 and 311 parallel connections of the first feedback filtering capacitor C is connected the other end ground connection after the parallel connection with the other end of thermistor RT1 and the inverting input of the first operational amplifier U1; One end of the sliding end of the first potentiometer RP1 and the second feedback filtering capacitor C 312 is connected with the in-phase input end of the first operational amplifier U1, one of the first potentiometer RP1 fixing termination+15V accessory power supply, another stiff end of the first potentiometer RP1, the other end of the second feedback filtering capacitor C 312, the negative power end ground connection of the first operational amplifier U1, one termination of the positive power source terminal of the first operational amplifier U1 and the first pull-up resistor R312+15V accessory power supply, the output of the other end of the first pull-up resistor R312 and the first operational amplifier U1 is connected the source ground of the first metal-oxide-semiconductor field effect transistor Q311 with the grid of the first metal-oxide-semiconductor field effect transistor Q311.
Described voltage sampling circuit comprises first resistance R 321, second resistance R 322, Hall voltage transducer U2.One end of first resistance R 321 is connected with the voltage output end of one-level reduction voltage circuit or secondary reduction voltage circuit, the other end of first resistance R 321 is connected with 1 pin of Hall voltage transducer U2, the 2 pin ground connection of Hall voltage transducer U2,4 pin of Hall voltage transducer U2 connect+and 15V accessory power supply, 5 pin connect-the 15V accessory power supply, 3 pin of Hall voltage transducer U2 are connected with an end of second resistance R 322, the other end ground connection of second resistance R 322.
Described PWM produces circuit and comprises accurate voltage-stabiliser tube U3, pulse width modulator SG3525AN, fuse F1, first capacitor C 331, second capacitor C 332, the 3rd capacitor C 333, the first electrochemical capacitor C334, the 3rd resistance R 331, the 4th resistance R 332, the 5th resistance R 333, the 6th resistance R 334, the 7th resistance R 335, the 8th resistance R 336, the 9th resistance R 337, the tenth resistance R the 338, the 11 resistance R 339.1 pin of accurate voltage-stabiliser tube U3 is connected with 3 pin of Hall voltage transducer U2 by fuse F1,3 pin of accurate voltage-stabiliser tube U3 are connected with an end of the 3rd resistance R 331, an end of the 4th resistance R 332 and an end of first capacitor C 331, another termination+15V accessory power supply of the 3rd resistance R 331, the other end ground connection of 2 pin of accurate voltage-stabiliser tube U3 and first capacitor C 331; 16 pin of pulse width modulator SG3525AN are connected with an end of the 6th resistance R 334, one end of the other end of the other end of the 6th resistance R 334, the 4th resistance R 332, the 5th resistance R 333 all is connected with 2 pin of pulse width modulator SG3525AN, the other end ground connection of the 5th resistance R 333; 6 pin of pulse width modulator SG3525AN are connected with an end of the 7th resistance R 335, the other end ground connection of the 7th resistance R 335; 7 pin of pulse width modulator SG3525AN are connected with an end of the 8th resistance R 336, and an end of the other end of the 8th resistance R 336, second capacitor C 332 is connected with 5 pin of pulse width modulator SG3525AN; 1 pin of pulse width modulator SG3525AN is connected with an end of the 9th resistance R 337, one end of the other end of the 9th resistance R 337 and the 3rd capacitor C 333 is connected with 9 pin of pulse width modulator SG3525AN, the other end ground connection of 12 pin of pulse width modulator SG3525AN, the other end of second capacitor C 332, the 3rd capacitor C 333; 13 and 15 pin of pulse width modulator SG3525AN connect+the 15V accessory power supply, 14 pin of pulse width modulator SG3525AN are connected with an end of the tenth resistance R 338,8 pin of pulse width modulator SG3525AN are connected with the positive pole of the first electrochemical capacitor C334,10 pin of pulse width modulator SG3525AN are connected with an end of the 11 resistance R 339, the other end ground connection of the negative pole of the first electrochemical capacitor C334, the 11 resistance R 339.
Described IGBT drive circuit comprises IGBT chip for driving M57959, triode Q341, the first diode D341, the second diode D342, the second electrochemical capacitor C341, the 3rd electrochemical capacitor C342, the 12 resistance R the 341, the 13 resistance R the 342, the 14 resistance R 343.The negative electrode of the anode of the first diode D341 and the second diode D342 is connected with 1 pin of IGBT chip for driving M57959, the negative electrode of the first diode D341 is connected with the collector electrode of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2, the anode of the second diode D342,6 pin of the negative pole of the second electrochemical capacitor C341 and IGBT chip for driving M57959 connect-the 10V accessory power supply, and the emitter of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2 is connected and ground connection with the negative pole anodal and the 3rd electrochemical capacitor C342 of the second electrochemical capacitor C341; 4 pin of the positive pole of the 3rd electrochemical capacitor C342 and IGBT chip for driving M57959 connect+the 15V accessory power supply, 5 pin of IGBT chip for driving M57959 are connected with an end of the 12 resistance R 341, and the other end of the 12 resistance R 341 is connected with the base stage of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2; 13 pin of IGBT chip for driving M57959 are connected with an end of the collector electrode of triode Q341 and the 13 resistance R 342, another termination+15V accessory power supply of the 13 resistance R 342, the base stage of triode Q341 is connected with the other end of the tenth resistance R 338, the grounded emitter of triode Q341; 14 pin of IGBT chip for driving M57959 are connected with an end of the 14 resistance R 343, another termination+15V accessory power supply of the 14 resistance R 343.
The auxiliary feedback regulating circuit of described output voltage comprises optocoupler U4, the second potentiometer RP2, the second operational amplifier U5, the second metal-oxide-semiconductor field effect transistor Q351, the 4th capacitor C 351, the 5th capacitor C the 352, the 15 resistance R the 351, the 16 resistance R the 352, the 17 resistance R the 353, the 18 resistance R 354.1 pin of optocoupler U4 is connected with 1 pin of Hall voltage transducer U2,2 pin are connected with 2 pin of Hall voltage transducer U2,3 pin of optocoupler U4 are connected with an end of the 16 resistance R 352,4 pin are connected another termination+15V accessory power supply of the 15 resistance R 351 with an end of the 15 resistance R 351; The other end of the 16 resistance R 352, one end of the 17 resistance R 353, one end of the 5th capacitor C 352 is connected with the in-phase input end of the second operational amplifier U5, one end of the 4th capacitor C 351, the sliding end of the second potentiometer RP2 is connected with the inverting input of the second operational amplifier U5, one end of the grid of the second metal-oxide-semiconductor field effect transistor Q351 and the 18 resistance R 354 is connected with the output of the second operational amplifier U7, the positive power source terminal of the second operational amplifier U5, the other end of the 18 resistance R 354, one of the second potentiometer RP2 fixing termination+15V accessory power supply, another stiff end ground connection of the other end of the 4th capacitor C 351 and the second potentiometer RP2; The drain electrode of the second metal-oxide-semiconductor field effect transistor Q351 is connected with the base stage of triode Q341, the source ground of the other end of the other end of the 17 resistance R 353, the 5th capacitor C 352, the negative power end of the second operational amplifier U7, the second metal-oxide-semiconductor field effect transistor Q351.
The utility model utilizes the continuous step-down of two-stage, has broken through the excessive barrier of pressure reduction, can carry out step-down high-voltage dc voltage is stable, efficiently, accurately, safely.
Description of drawings
Fig. 1 is a circuit structure block diagram of the present utility model;
Fig. 2 is a prime current filtering circuit diagram among Fig. 1;
Fig. 3 is one-level reduction voltage circuit figure among Fig. 1;
Fig. 4 is secondary reduction voltage circuit figure among Fig. 1;
Fig. 5 is the Temperature Feedback regulating circuit figure in the feedback circuit;
Fig. 6 is that voltage sampling circuit, the PWM in the feedback circuit produces circuit, IGBT drive circuit figure;
Fig. 7 is the auxiliary feedback regulating circuit figure of the output voltage in the feedback circuit.
Embodiment
With specific embodiment the utility model is further elaborated with reference to the accompanying drawings below.
A kind of voltage reduction circuits of high power switching power supply can be with the dc voltage stability of 1000V, be reduced to 300V efficiently, accurately, safely.
As shown in Figure 1, this circuit comprises that prime current filtering circuit 4, one-level reduction voltage circuit 1, diode D, secondary reduction voltage circuit 2 and two feedback circuits 3 constitute.One end of prime current filtering circuit 4 is connected with the positive pole of DC input voitage, and the end after one-level reduction voltage circuit 1 and the feedback circuit parallel connection is connected with the other end of prime current filtering circuit 4, and the other end after the parallel connection is connected with the anode of diode D; End after secondary reduction voltage circuit 2 and another feedback circuit parallel connection is connected with the negative electrode of diode D, and the other end is as voltage output end.Prime current filtering circuit 4 both can suppress to be produced and to the interference of input equipment feedback, also can be suppressed the noise from input equipment by Switching Power Supply, reduced the infringement to power supply itself.One-level reduction voltage circuit 1 and secondary reduction voltage circuit 2 are used for big voltage is realized the continuous step-down processing of two-stage, can alleviate owing to the excessive problem of the excessive current pulsation that causes of the pressure reduction between the input and output voltage.
As shown in Figure 2, prime current filtering circuit comprises prime filter inductance L41, the first filter capacitor C41, the second filter capacitor C42, the 3rd filter capacitor C43.The end of filter inductance L41 is connected with the positive pole of DC input voitage, negativing ending grounding after the prime first filter capacitor C41, the prime second filter capacitor C42 and prime the 3rd filter capacitor C43 series connection, the anode after the series connection is connected with the other end of prime filter inductance L41.Carry the DC input voitage of 1000V by the series connection of three filter capacitors.
The one-level reduction voltage circuit can be realized the buck functionality of direct current 1000V to 600V.As shown in Figure 3, the one-level reduction voltage circuit comprises one-level insulated gate bipolar transistor Q11 (K25T120), one-level backward diode D11, one-level sustained diode 12, one-level energy storage inductor L11, one-level filter inductance L12, the one-level first filter capacitor C11, the one-level second filter capacitor C12, one-level the 3rd filter capacitor C13, one-level the 4th filter capacitor C14.One-level insulated gate bipolar transistor Q11 is as switch element, the negative electrode of one-level backward diode D11 is connected with the collector electrode of one-level insulated gate bipolar transistor Q11 and the other end of prime filter inductance L41, the end of the anode of one-level backward diode D11, the negative electrode of one-level sustained diode 12, one-level energy storage inductor L11 all is connected with the emitter of one-level insulated gate bipolar transistor Q11, the plus earth of one-level sustained diode 12, one-level backward diode D11 is used for protecting one-level insulated gate bipolar transistor Q11; Anode after the one-level first filter capacitor C11 and the one-level second filter capacitor C12 series connection is connected the negativing ending grounding after the series connection with the other end of one-level energy storage inductor L11 and the end of one-level filter inductance L12; Anode after one-level the 3rd filter capacitor C13 and one-level the 4th filter capacitor C14 series connection is connected the negativing ending grounding after the series connection with the other end of one-level filter inductance L12 and the anode of diode D.
The secondary reduction voltage circuit is realized the DC decompression function of 600V to 300V.As shown in Figure 4, the secondary reduction voltage circuit comprises secondary insulated gate bipolar transistor Q2 (K25T120), secondary backward diode D3, secondary sustained diode 4, secondary energy storage inductor L4, secondary filter inductance L5, the secondary first filter capacitor C21, the secondary second filter capacitor C22.Secondary insulated gate bipolar transistor Q2 is as switch element, the negative electrode of secondary backward diode D3 is connected with the collector electrode of secondary insulated gate bipolar transistor Q2 and the negative electrode of diode D connects, the end of the anode of secondary backward diode D3, the negative electrode of secondary sustained diode 4, secondary energy storage inductor L4 all is connected the plus earth of secondary sustained diode 4 with the emitter of secondary insulated gate bipolar transistor Q2; The end of the anode of the secondary first filter capacitor C21, secondary filter inductance L5 is connected with the other end of secondary energy storage inductor L4, the negativing ending grounding of the secondary first filter capacitor C21; The anode of the secondary second filter capacitor C22 is connected with the other end of secondary filter inductance L5, as voltage output end, and the negativing ending grounding of the secondary second filter capacitor C22.
The secondary reduction voltage circuit comprises secondary insulated gate bipolar transistor Q21 (K25T120), secondary backward diode D21, secondary sustained diode 22, secondary energy storage inductor L21, secondary filter inductance L22, the secondary first filter capacitor C21, the secondary second filter capacitor C22.The negative electrode of secondary backward diode D21 is connected with the collector electrode of secondary insulated gate bipolar transistor Q21 and the negative electrode of diode D connects, the end of the anode of secondary backward diode D21, the negative electrode of secondary sustained diode 22, secondary energy storage inductor L21 all is connected the plus earth of secondary sustained diode 22 with the emitter of secondary insulated gate bipolar transistor Q21; The end of the anode of the secondary first filter capacitor C21, secondary filter inductance L22 is connected with the other end of secondary energy storage inductor L21, the negativing ending grounding of the secondary first filter capacitor C21; The anode of the secondary second filter capacitor C22 is connected with the other end of secondary filter inductance L22, as voltage output end, and the negativing ending grounding of the secondary second filter capacitor C22.
The LC filter circuit of above-mentioned one-level reduction voltage circuit and secondary reduction voltage circuit output and prime current filtering circuit are formed by less loop filtering inductance and bigger electrochemical capacitor, the high-frequency inductor that one-level energy storage inductor L11 and the secondary second energy storage inductor L21 use the ferrocart core material to make, improve the anti-saturation ability of inductance, its parameter can be according to L=[(Vi-Vo) * Vo * T]/2 * K * Vi * Io obtains, wherein K is the ratio of maximum current and minimum current, is 10 in this example.One-level filter inductance L12 and secondary filter inductance L22 use the iron silica-alumina material, reduce the energy loss of circuit.Its cut-off frequency is F=1/[2 * π * (L * C)
1/2], generally when cut-off frequency is 10 times of ripple frequency of required filtering, can more efficiently reduce the switch noise of exporting.Switch operating frequency f in this example is 4kHZ, and choosing filter inductance is 10uH, and filter inductance is difficult for getting too big, and too conference causes the resonance of circuit, worsens the output quality of source current, according to 10f=1/{2 * π * [L3 * (C6+C7)/2]
1/2, the parameter that can obtain being correlated with.
As shown in Figure 1, on the output loop of one-level reduction voltage circuit 1 and secondary reduction voltage circuit 2, be loaded with 3, two feedback circuits of feedback circuit 3 respectively and adopt identical circuit structure.Feedback circuit comprises that Temperature Feedback regulating circuit 3-1, voltage sampling circuit 3-2, PWM produce circuit 3-3 and IGBT drive circuit 3-4, the auxiliary feedback regulating circuit 3-5 of output voltage.Voltage sampling circuit 3-2, PWM produce circuit 3-3 and IGBT drive circuit 3-4 is followed in series to form output voltage primary feedback regulating circuit, can guarantee the precision of reduction voltage circuit according to the duty ratio of the meticulous by-pass cock pipe of system's output voltage, electric current and variation of temperature.
Temperature Feedback regulating circuit 3-1 passes through the real time temperature of detection system inside, and the temperature of detected temperature and setting is compared, thereby judges the conducting and the shutoff of switching tube.This feedback high temperature that can give warning in advance turn-offed main circuit before system overheat, guarantee system safety.Its circuit structure comprises thermistor RT1, the first potentiometer RP1, the first operational amplifier U1, the first metal-oxide-semiconductor field effect transistor Q311 (IRF540N), the first divider resistance R311, the first pull-up resistor R312, the first feedback filtering capacitor C 311, the second feedback filtering capacitor C 312 as shown in Figure 5.Thermistor RT1 is placed on the circuit board of one-level reduction voltage circuit 1 or secondary reduction voltage circuit 2, is used for the detection system temperature.One termination of thermistor RT1+15V accessory power supply, end after the first divider resistance R311 and 311 parallel connections of the first feedback filtering capacitor C is connected the other end ground connection after the parallel connection with the other end of thermistor RT1 and the inverting input of the first operational amplifier U1; One end of the sliding end of the first potentiometer RP1 and the second feedback filtering capacitor C 312 is connected with the in-phase input end of the first operational amplifier U1, one of the first potentiometer RP1 fixing termination+15V accessory power supply, another stiff end of the first potentiometer RP1, the other end of the second feedback filtering capacitor C 312, the negative power end ground connection of the first operational amplifier U1, one termination of the positive power source terminal of the first operational amplifier U1 and the first pull-up resistor R312+15V accessory power supply, the output of the other end of the first pull-up resistor R312 and the first operational amplifier U1 is connected the source ground of the first metal-oxide-semiconductor field effect transistor Q311 with the grid of the first metal-oxide-semiconductor field effect transistor Q311.This circuit can be determined the shutoff temperature of switching tube by the resistance of setting the first potentiometer RP1.When the resistance of thermistor during greater than the set point of first potentiometer, conducting between the drain electrode of the first metal-oxide-semiconductor field effect transistor Q311 and the source electrode, this moment, triode Q341 turn-offed, thereby by IGBT drive circuit 3-4 on-off switching tube.
Voltage sampling circuit 3-2 is converted to current signal to output voltage signal by the Hall voltage transducer, comprises first resistance R 321, second resistance R 322, Hall voltage transducer U2 (VSM025A).One end of first resistance R 321 is connected with the voltage output end of one-level reduction voltage circuit or secondary reduction voltage circuit, the other end of first resistance R 321 is connected with 1 pin of Hall voltage transducer U2, the 2 pin ground connection of Hall voltage transducer U2,4 pin of Hall voltage transducer U2 connect+and 15V accessory power supply, 5 pin connect-the 15V accessory power supply, 3 pin of Hall voltage transducer U2 are connected with an end of second resistance R 322, the other end ground connection of second resistance R 322.
PWM produces circuit 3-3 and by accurate voltage-stabiliser tube the current signal of voltage sample unit output is converted into Transistor-Transistor Logic level information, is input in the pulse-width modulator, and by the triode output pwm signal, realizes that the automatic voltage regulation of circuit is regulated.PWM produces circuit 3-3 and comprises accurate voltage-stabiliser tube U3 (TL431CLP), pulse width modulator SG3525AN, fuse F1, first capacitor C 331, second capacitor C 332, the 3rd capacitor C 333, the first electrochemical capacitor C334, the 3rd resistance R 331, the 4th resistance R 332, the 5th resistance R 333, the 6th resistance R 334, the 7th resistance R 335, the 8th resistance R 336, the 9th resistance R 337, the tenth resistance R the 338, the 11 resistance R 339.1 pin of accurate voltage-stabiliser tube U3 is connected with 3 pin of Hall voltage transducer U2 by fuse F1,3 pin of accurate voltage-stabiliser tube U3 are connected with an end of the 3rd resistance R 331, an end of the 4th resistance R 332 and an end of first capacitor C 331, another termination+15V accessory power supply of the 3rd resistance R 331, the other end ground connection of 2 pin of accurate voltage-stabiliser tube U3 and first capacitor C 331; 16 pin of pulse width modulator SG3525AN are connected with an end of the 6th resistance R 334, one end of the other end of the other end of the 6th resistance R 334, the 4th resistance R 332, the 5th resistance R 333 all is connected with 2 pin of pulse width modulator SG3525AN, the other end ground connection of the 5th resistance R 333; 6 pin of pulse width modulator SG3525AN are connected with an end of the 7th resistance R 335, the other end ground connection of the 7th resistance R 335; 7 pin of pulse width modulator SG3525AN are connected with an end of the 8th resistance R 336, and an end of the other end of the 8th resistance R 336, second capacitor C 332 is connected with 5 pin of pulse width modulator SG3525AN; 1 pin of pulse width modulator SG3525AN is connected with an end of the 9th resistance R 337, one end of the other end of the 9th resistance R 337 and the 3rd capacitor C 333 is connected with 9 pin of pulse width modulator SG3525AN, the other end ground connection of 12 pin of pulse width modulator SG3525AN, the other end of second capacitor C 332, the 3rd capacitor C 333; 13 and 15 pin of pulse width modulator SG3525AN connect+the 15V accessory power supply, 14 pin of pulse width modulator SG3525AN are connected with an end of the tenth resistance R 338,8 pin of pulse width modulator SG3525AN are connected with the positive pole of the first electrochemical capacitor C334,10 pin of pulse width modulator SG3525AN are connected with an end of the 11 resistance R 339, the other end ground connection of the negative pole of the first electrochemical capacitor C334, the 11 resistance R 339.
IGBT drive circuit 3-4 is input to the break-make of controlling IGBT in the IGBT chip for driving to the pwm signal that PWM produces circuit 3-3 output by the IGBT chip for driving.IGBT drive circuit 3-4 comprises IGBT chip for driving M57959, triode Q341, the first diode D341, the second diode D342, the second electrochemical capacitor C341, the 3rd electrochemical capacitor C342, the 12 resistance R the 341, the 13 resistance R the 342, the 14 resistance R 343.The negative electrode of the anode of the first diode D341 and the second diode D342 is connected with 1 pin of IGBT chip for driving M57959, the negative electrode of the first diode D341 is connected with the collector electrode of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2, the anode of the second diode D342,6 pin of the negative pole of the second electrochemical capacitor C341 and IGBT chip for driving M57959 connect-the 10V accessory power supply, and the emitter of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2 is connected and ground connection with the negative pole anodal and the 3rd electrochemical capacitor C342 of the second electrochemical capacitor C341; 4 pin of the positive pole of the 3rd electrochemical capacitor C342 and IGBT chip for driving M57959 connect+the 15V accessory power supply, 5 pin of IGBT chip for driving M57959 are connected with an end of the 12 resistance R 341, and the other end of the 12 resistance R 341 is connected with the base stage of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2; 13 pin of IGBT chip for driving M57959 are connected with an end of the collector electrode of triode Q341 and the 13 resistance R 342, another termination+15V accessory power supply of the 13 resistance R 342, the base stage of triode Q341 is connected with the other end of the tenth resistance R 338, the grounded emitter of triode Q341; 14 pin of IGBT chip for driving M57959 are connected with an end of the 14 resistance R 343, another termination+15V accessory power supply of the 14 resistance R 343.
The voltage stabilizing value of accurate voltage-stabiliser tube U3 (TL431CLP) is 2.495V in this example, and the 1 pin input current of Hall voltage transducer U2 (VSM025A) equates that with the output current value of 3 pin promptly Vo/R7=2.495/R8 can determine relevant parameter according to this equation.When the input voltage of accurate voltage-stabiliser tube U3 (TL431CLP) is not its voltage stabilizing value, conducting between 2 pin of accurate voltage-stabiliser tube U3 (TL431CLP) and 3 pin, make the 14 pin output LOW voltages of pulse width modulator SG3525AN this moment by the adjusting of pulse width modulator SG3525AN, triode Q341 works in cut-off state, thereby by IGBT drive circuit 3-4 on-off switching tube.
When output voltage primary feedback regulating circuit breaks down, can utilize output voltage to assist feedback regulating circuit 3-5 on-off switching tube, thereby avoid the damage of switching tube.As shown in Figure 7, the auxiliary feedback regulating circuit 3-5 of output voltage comprises optocoupler U4 (PC817), the second potentiometer RP2, the second operational amplifier U5, the second metal-oxide-semiconductor field effect transistor Q351 (IRF540N), the 4th capacitor C 351, the 5th capacitor C the 352, the 15 resistance R the 351, the 16 resistance R the 352, the 17 resistance R the 353, the 18 resistance R 354.1 pin of optocoupler U4 is connected with 1 pin of Hall voltage transducer U2,2 pin are connected with 2 pin of Hall voltage transducer U2,3 pin of optocoupler U4 are connected with an end of the 16 resistance R 352,4 pin are connected another termination+15V accessory power supply of the 15 resistance R 351 with an end of the 15 resistance R 351; The other end of the 16 resistance R 352, one end of the 17 resistance R 353, one end of the 5th capacitor C 352 is connected with the in-phase input end of the second operational amplifier U5, one end of the 4th capacitor C 351, the sliding end of the second potentiometer RP2 is connected with the inverting input of the second operational amplifier U5, one end of the grid of the second metal-oxide-semiconductor field effect transistor Q351 and the 18 resistance R 354 is connected with the output of the second operational amplifier U7, the positive power source terminal of the second operational amplifier U5, the other end of the 18 resistance R 354, one of the second potentiometer RP2 fixing termination+15V accessory power supply, another stiff end ground connection of the other end of the 4th capacitor C 351 and the second potentiometer RP2; The drain electrode of the second metal-oxide-semiconductor field effect transistor Q351 is connected with the base stage of triode Q341, the source ground of the other end of the other end of the 17 resistance R 353, the 5th capacitor C 352, the negative power end of the second operational amplifier U7, the second metal-oxide-semiconductor field effect transistor Q351.When output voltage primary feedback regulating circuit causes opening circuit because of breaking down, cause conducting between 4 pin of optocoupler U4 and 3 pin, after the voltage of importing the second operational amplifier U5 in-phase input end is drawn high, cause conducting between the drain electrode of the second metal-oxide-semiconductor field effect transistor Q351 and the source electrode, this moment, triode Q341 turn-offed, thereby by IGBT drive circuit 3-4 on-off switching tube.
After three reduction voltage circuits that are made of one-level reduction voltage circuit, diode D, secondary reduction voltage circuit and two feedback circuits can being connected in parallel on prime current filtering circuit in the practical application, article three, reduction voltage circuit is realized autonomous current-sharing buck functionality respectively, the parallel redundancy of sort circuit guaranteed system still can be reliably under situation about being partially damaged, work safely.
In sum, the utility model utilizes the multichannel feedback network that reduction voltage circuit is realized from main regulation, utilizes the continuous step-down of two-stage to break through the excessive barrier of pressure reduction, utilizes multi-channel parallel current-sharing step-down to improve the stability of circuit, facts have proved that effect is fine.
Claims (1)
1. a Switching Power Supply reduction voltage circuit is characterized in that this circuit comprises prime current filtering circuit, one-level reduction voltage circuit, diode D, secondary reduction voltage circuit and two feedback circuits; One end of prime current filtering circuit is connected with the positive pole of DC input voitage, and the end after one-level reduction voltage circuit and the feedback circuit parallel connection is connected with the other end of prime current filtering circuit, and the other end after the parallel connection is connected with the anode of diode D; End after secondary reduction voltage circuit and another feedback circuit parallel connection is connected with the negative electrode of diode D, and the other end is as voltage output end; Physical circuit is as follows:
Prime current filtering circuit comprises prime filter inductance L41, the first filter capacitor C41, the second filter capacitor C42, the 3rd filter capacitor C43; The end of filter inductance L41 is connected with the positive pole of DC input voitage, negativing ending grounding after the prime first filter capacitor C41, the prime second filter capacitor C42 and prime the 3rd filter capacitor C43 series connection, the anode after the series connection is connected with the other end of prime filter inductance L41;
The one-level reduction voltage circuit comprises one-level insulated gate bipolar transistor Q11, one-level backward diode D11, one-level sustained diode 12, one-level energy storage inductor L11, one-level filter inductance L12, the one-level first filter capacitor C11, the one-level second filter capacitor C12, one-level the 3rd filter capacitor C13, one-level the 4th filter capacitor C14; The negative electrode of one-level backward diode D11 is connected with the collector electrode of one-level insulated gate bipolar transistor Q11 and the other end of prime filter inductance L41, the end of the anode of one-level backward diode D11, the negative electrode of one-level sustained diode 12, one-level energy storage inductor L11 all is connected the plus earth of one-level sustained diode 12 with the emitter of one-level insulated gate bipolar transistor Q11; Anode after the one-level first filter capacitor C11 and the one-level second filter capacitor C12 series connection is connected the negativing ending grounding after the series connection with the other end of one-level energy storage inductor L11 and the end of one-level filter inductance L12; Anode after one-level the 3rd filter capacitor C13 and one-level the 4th filter capacitor C14 series connection is connected the negativing ending grounding after the series connection with the other end of one-level filter inductance L12 and the anode of diode D;
The secondary reduction voltage circuit comprises secondary insulated gate bipolar transistor Q21, secondary backward diode D21, secondary sustained diode 22, secondary energy storage inductor L21, secondary filter inductance L22, the secondary first filter capacitor C21, the secondary second filter capacitor C22; The negative electrode of secondary backward diode D21 is connected with the collector electrode of secondary insulated gate bipolar transistor Q21 and the negative electrode of diode D connects, the end of the anode of secondary backward diode D21, the negative electrode of secondary sustained diode 22, secondary energy storage inductor L21 all is connected the plus earth of secondary sustained diode 22 with the emitter of secondary insulated gate bipolar transistor Q21; The end of the anode of the secondary first filter capacitor C21, secondary filter inductance L22 is connected with the other end of secondary energy storage inductor L21, the negativing ending grounding of the secondary first filter capacitor C21; The anode of the secondary second filter capacitor C22 is connected with the other end of secondary filter inductance L22, as voltage output end, and the negativing ending grounding of the secondary second filter capacitor C22;
Feedback circuit comprises that Temperature Feedback regulating circuit, voltage sampling circuit, PWM produce circuit, IGBT drive circuit, the auxiliary feedback regulating circuit of output voltage;
Described Temperature Feedback regulating circuit comprises thermistor RT1, the first potentiometer RP1, the first operational amplifier U1, the first metal-oxide-semiconductor field effect transistor Q311, the first divider resistance R311, the first pull-up resistor R312, the first feedback filtering capacitor C 311, the second feedback filtering capacitor C 312; Thermistor RT1 is placed on the circuit board of one-level reduction voltage circuit 1 or secondary reduction voltage circuit 2, one termination of thermistor RT1+15V accessory power supply, end after the first divider resistance R311 and 311 parallel connections of the first feedback filtering capacitor C is connected the other end ground connection after the parallel connection with the other end of thermistor RT1 and the inverting input of the first operational amplifier U1; One end of the sliding end of the first potentiometer RP1 and the second feedback filtering capacitor C 312 is connected with the in-phase input end of the first operational amplifier U1, one of the first potentiometer RP1 fixing termination+15V accessory power supply, another stiff end of the first potentiometer RP1, the other end of the second feedback filtering capacitor C 312, the negative power end ground connection of the first operational amplifier U1, one termination of the positive power source terminal of the first operational amplifier U1 and the first pull-up resistor R312+15V accessory power supply, the output of the other end of the first pull-up resistor R312 and the first operational amplifier U1 is connected the source ground of the first metal-oxide-semiconductor field effect transistor Q311 with the grid of the first metal-oxide-semiconductor field effect transistor Q311;
Described voltage sampling circuit comprises first resistance R 321, second resistance R 322, Hall voltage transducer U2; One end of first resistance R 321 is connected with the voltage output end of one-level reduction voltage circuit or secondary reduction voltage circuit, the other end of first resistance R 321 is connected with 1 pin of Hall voltage transducer U2, the 2 pin ground connection of Hall voltage transducer U2,4 pin of Hall voltage transducer U2 connect+and 15V accessory power supply, 5 pin connect-the 15V accessory power supply, 3 pin of Hall voltage transducer U2 are connected with an end of second resistance R 322, the other end ground connection of second resistance R 322;
Described PWM produces circuit and comprises accurate voltage-stabiliser tube U3, pulse width modulator SG3525AN, fuse F1, first capacitor C 331, second capacitor C 332, the 3rd capacitor C 333, the first electrochemical capacitor C334, the 3rd resistance R 331, the 4th resistance R 332, the 5th resistance R 333, the 6th resistance R 334, the 7th resistance R 335, the 8th resistance R 336, the 9th resistance R 337, the tenth resistance R the 338, the 11 resistance R 339; 1 pin of accurate voltage-stabiliser tube U3 is connected with 3 pin of Hall voltage transducer U2 by fuse F1,3 pin of accurate voltage-stabiliser tube U3 are connected with an end of the 3rd resistance R 331, an end of the 4th resistance R 332 and an end of first capacitor C 331, another termination+15V accessory power supply of the 3rd resistance R 331, the other end ground connection of 2 pin of accurate voltage-stabiliser tube U3 and first capacitor C 331; 16 pin of pulse width modulator SG3525AN are connected with an end of the 6th resistance R 334, one end of the other end of the other end of the 6th resistance R 334, the 4th resistance R 332, the 5th resistance R 333 all is connected with 2 pin of pulse width modulator SG3525AN, the other end ground connection of the 5th resistance R 333; 6 pin of pulse width modulator SG3525AN are connected with an end of the 7th resistance R 335, the other end ground connection of the 7th resistance R 335; 7 pin of pulse width modulator SG3525AN are connected with an end of the 8th resistance R 336, and an end of the other end of the 8th resistance R 336, second capacitor C 332 is connected with 5 pin of pulse width modulator SG3525AN; 1 pin of pulse width modulator SG3525AN is connected with an end of the 9th resistance R 337, one end of the other end of the 9th resistance R 337 and the 3rd capacitor C 333 is connected with 9 pin of pulse width modulator SG3525AN, the other end ground connection of 12 pin of pulse width modulator SG3525AN, the other end of second capacitor C 332, the 3rd capacitor C 333; 13 and 15 pin of pulse width modulator SG3525AN connect+the 15V accessory power supply, 14 pin of pulse width modulator SG3525AN are connected with an end of the tenth resistance R 338,8 pin of pulse width modulator SG3525AN are connected with the positive pole of the first electrochemical capacitor C334,10 pin of pulse width modulator SG3525AN are connected with an end of the 11 resistance R 339, the other end ground connection of the negative pole of the first electrochemical capacitor C334, the 11 resistance R 339;
Described IGBT drive circuit comprises IGBT chip for driving M57959, triode Q341, the first diode D341, the second diode D342, the second electrochemical capacitor C341, the 3rd electrochemical capacitor C342, the 12 resistance R the 341, the 13 resistance R the 342, the 14 resistance R 343; The negative electrode of the anode of the first diode D341 and the second diode D342 is connected with 1 pin of IGBT chip for driving M57959, the negative electrode of the first diode D341 is connected with the collector electrode of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2, the anode of the second diode D342,6 pin of the negative pole of the second electrochemical capacitor C341 and IGBT chip for driving M57959 connect-the 10V accessory power supply, and the emitter of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2 is connected and ground connection with the negative pole anodal and the 3rd electrochemical capacitor C342 of the second electrochemical capacitor C341; 4 pin of the positive pole of the 3rd electrochemical capacitor C342 and IGBT chip for driving M57959 connect+the 15V accessory power supply, 5 pin of IGBT chip for driving M57959 are connected with an end of the 12 resistance R 341, and the other end of the 12 resistance R 341 is connected with the base stage of one-level insulated gate bipolar transistor Q1 or secondary insulated gate bipolar transistor Q2; 13 pin of IGBT chip for driving M57959 are connected with an end of the collector electrode of triode Q341 and the 13 resistance R 342, another termination+15V accessory power supply of the 13 resistance R 342, the base stage of triode Q341 is connected with the other end of the tenth resistance R 338, the grounded emitter of triode Q341; 14 pin of IGBT chip for driving M57959 are connected with an end of the 14 resistance R 343, another termination+15V accessory power supply of the 14 resistance R 343;
The auxiliary feedback regulating circuit of described output voltage comprises optocoupler U4, the second potentiometer RP2, the second operational amplifier U5, the second metal-oxide-semiconductor field effect transistor Q351, the 4th capacitor C 351, the 5th capacitor C the 352, the 15 resistance R the 351, the 16 resistance R the 352, the 17 resistance R the 353, the 18 resistance R 354; 1 pin of optocoupler U4 is connected with 1 pin of Hall voltage transducer U2,2 pin are connected with 2 pin of Hall voltage transducer U2,3 pin of optocoupler U4 are connected with an end of the 16 resistance R 352,4 pin are connected another termination+15V accessory power supply of the 15 resistance R 351 with an end of the 15 resistance R 351; The other end of the 16 resistance R 352, one end of the 17 resistance R 353, one end of the 5th capacitor C 352 is connected with the in-phase input end of the second operational amplifier U5, one end of the 4th capacitor C 351, the sliding end of the second potentiometer RP2 is connected with the inverting input of the second operational amplifier U5, one end of the grid of the second metal-oxide-semiconductor field effect transistor Q351 and the 18 resistance R 354 is connected with the output of the second operational amplifier U7, the positive power source terminal of the second operational amplifier U5, the other end of the 18 resistance R 354, one of the second potentiometer RP2 fixing termination+15V accessory power supply, another stiff end ground connection of the other end of the 4th capacitor C 351 and the second potentiometer RP2; The drain electrode of the second metal-oxide-semiconductor field effect transistor Q351 is connected with the base stage of triode Q341, the source ground of the other end of the other end of the 17 resistance R 353, the 5th capacitor C 352, the negative power end of the second operational amplifier U7, the second metal-oxide-semiconductor field effect transistor Q351.
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| CN2010201549136U CN201623630U (en) | 2010-04-09 | 2010-04-09 | Voltage-reducing circuit of switch power supply |
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| CN2010201549136U CN201623630U (en) | 2010-04-09 | 2010-04-09 | Voltage-reducing circuit of switch power supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101795065A (en) * | 2010-04-09 | 2010-08-04 | 杭州电子科技大学 | Voltage reduction circuits of high power switching power supply |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101795065A (en) * | 2010-04-09 | 2010-08-04 | 杭州电子科技大学 | Voltage reduction circuits of high power switching power supply |
| CN101795065B (en) * | 2010-04-09 | 2012-06-06 | 杭州电子科技大学 | Voltage reduction circuits of high power switching power supply |
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