CN107888066A - A kind of inverse-excitation type switch power-supply circuit - Google Patents

A kind of inverse-excitation type switch power-supply circuit Download PDF

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Publication number
CN107888066A
CN107888066A CN201711463574.2A CN201711463574A CN107888066A CN 107888066 A CN107888066 A CN 107888066A CN 201711463574 A CN201711463574 A CN 201711463574A CN 107888066 A CN107888066 A CN 107888066A
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CN
China
Prior art keywords
circuit
input
inverse
resistance
output
Prior art date
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Pending
Application number
CN201711463574.2A
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Chinese (zh)
Inventor
易成林
丁振
赵亚峰
朱爱玲
陈凡
程琳
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Zhejiang Chint Instrument and Meter Co Ltd
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Zhejiang Chint Instrument and Meter Co Ltd
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Priority to CN201711463574.2A priority Critical patent/CN107888066A/en
Publication of CN107888066A publication Critical patent/CN107888066A/en
Pending legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/14—Arrangements for reducing ripples from dc input or output
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/36—Means for starting or stopping converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0006—Arrangements for supplying an adequate voltage to the control circuit of converters

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses a kind of inverse-excitation type switch power-supply circuit, including：Electrical energy conversion circuit, pwm control circuit, on-off circuit and switch discharge circuit；The input of on-off circuit is connected with the output end of pwm control circuit, and the output end of on-off circuit is connected with the input of electrical energy conversion circuit；The input of switch discharge circuit is connected with the output end of on-off circuit, and the output end of switch discharge circuit is connected with the input of pwm control circuit；The control signal that on-off circuit is used to be sent according to pwm control circuit controls the break-make of electrical energy conversion circuit；Switch discharge circuit is used for electricity caused by the shut-off of release-push circuit.The energy stored after on-off circuit turns off every time can be reduced, reduces the possibility that on-off circuit is generated heat due to energy storage, improves the service life of on-off circuit.

Description

A kind of inverse-excitation type switch power-supply circuit
Technical field
The present invention relates to switch power technology field, more particularly to a kind of inverse-excitation type switch power-supply circuit.
Background technology
Switching Power Supply is that the voltage of one standard is converted into the required voltage of user terminal through various forms of frameworks Or a kind of power supply of electric current, and inverse-excitation type switch power-supply is the switch using flyback high frequency transformer isolation input output loop Power supply.The switching power source chip of inverse-excitation type switch power-supply adjusts the waveform of output according to the feedback signal of voltage change, including accounts for The adjustment of empty ratio or the adjustment of frequency, and then the voltage of main output loop is ensured to opposite direction change is changed before The stability of output loop output.
In the prior art, Publication No. CN204442186U Chinese patent literature discloses a kind of reverse exciting switching voltage regulator electricity Road, including ac rectifier, electromagnetic interference filter circuit, start-up circuit, flyback on-off circuit, output rectifier and filter, Control circuit and feedback circuit.Wherein, flyback on-off circuit includes flyback transformer and power tube.In above-mentioned patent document Power tube is connected with control circuit, and repeats to cut-off to form on-off circuit under the control of control circuit, so as to control flyback Transformer cut-offs, still, because power tube and control circuit are directly connected to, therefore, when power tube is in the control of control circuit Under from unlatching be converted to shut-off when, the electric capacity integrated on power tube can not discharge, and may result in power tube heating, shorten power The generation of the problem of service life of pipe.
The content of the invention
Therefore, the technical problem to be solved in the present invention is solve electricity caused by on-off circuit shut-off of the prior art The problem of amount can not discharge, and on-off circuit may be caused to generate heat, and service life is shorter.
Therefore, the invention provides a kind of inverse-excitation type switch power-supply circuit, including：Electrical energy conversion circuit, PWM control electricity Road, on-off circuit and switch discharge circuit；The input of on-off circuit is connected with the output end of pwm control circuit, switch electricity The output end on road is connected with the input of electrical energy conversion circuit, the input of switch discharge circuit and the output end of on-off circuit It is connected, the output end of switch discharge circuit is connected with the input of pwm control circuit；On-off circuit is used to be controlled according to PWM The break-make for the control signal control electrical energy conversion circuit that circuit processed is sent；When switch discharge circuit is used for the shut-off of release-push circuit Caused electricity.
Alternatively, on-off circuit is OSFET pipes Q1；Switch discharge circuit includes：First resistor R1 and the first diode D1； First resistor R1 one end is connected with MOSFET pipes Q1 grid, and the other end is connected with the first diode D1 anode；The One diode D1 negative electrode is connected with pwm control circuit.
Alternatively, switch discharge circuit also includes：Second resistance R2, second resistance R2 one end and first resistor R1 and MOSFET pipes Q1 grid is connected, and the other end is connected with the first diode D1 negative electrode and pwm control circuit.
Alternatively, switch discharge circuit also includes：3rd resistor R3,3rd resistor R3 one end and second resistance R2, the One resistance R1 is connected with MOSFET pipes Q1 grid, 3rd resistor R3 other end ground connection.
Alternatively, electrical energy conversion circuit includes input circuit, transformer circuit and output circuit；The input of transformer circuit End is connected with the output end of input circuit and the output end of on-off circuit, the output end of transformer circuit and output circuit Input is connected；Inverse-excitation type switch power-supply circuit also includes start-up circuit, the input of start-up circuit and input circuit it is defeated Go out end to be connected, the output end of start-up circuit is connected with the input of pwm control circuit；Start-up circuit is used for when inverse-excitation type is opened When powered-down source circuit starts, powered to pwm control circuit.
Alternatively, start-up circuit includes：4th resistance R4, the first electric capacity C1 and the second electric capacity C2；The one of 4th resistance R4 End is connected with input circuit, and the other end is connected with the first electric capacity C1, the second electric capacity C2 and pwm control circuit；First electric capacity C1 and the second electric capacity C2 other end are grounded.
Alternatively, pwm control circuit includes：Preferred circuit, feedback circuit and pwm chip；The input of preferred circuit End is connected with the output end of output circuit, the output end of preferred circuit and the input of output circuit and feedback circuit it is defeated Enter end to be connected；Preferred circuit is used for the voltage of stabilizing output circuit, and the magnitude of voltage of output circuit is sent to feedback circuit； The output end of feedback circuit is connected with the input of pwm chip；Feedback circuit is used for the magnitude of voltage of output circuit is anti- It is fed to pwm chip.
Alternatively, preferred circuit includes：Reference voltage source U1, the 5th resistance R5 and the 6th resistance R6；Reference voltage source U1 The first pin be connected with feedback circuit, second pin is connected with the 6th resistance R6 and ground wire, the 3rd pin and the 6th electricity The other end and the 5th resistance R5 for hindering R6 are connected；The 5th resistance R5 other end is connected with output circuit.
Alternatively, input circuit includes ripple filter circuit, and ripple filter circuit includes：3rd electric capacity C3 and the 7th resistance R7；3rd electric capacity C3 one end is connected with fire line terminal, and the other end is connected with zero terminal；The electricity of 7th resistance R7 and the 3rd It is in parallel to hold C3.
Technical scheme provided by the invention, has the following advantages that：
1st, inverse-excitation type switch power-supply circuit provided by the invention, including：Electrical energy conversion circuit, pwm control circuit, switch electricity Road and switch discharge circuit；The input of on-off circuit is connected with the output end of pwm control circuit, the output end of on-off circuit It is connected with the input of electrical energy conversion circuit, the input of switch discharge circuit is connected with the output end of on-off circuit, opens The output end for closing discharge circuit is connected with the input of pwm control circuit；On-off circuit is used to be sent according to pwm control circuit Control signal control electrical energy conversion circuit break-make；Switch discharge circuit is used for electricity caused by the shut-off of release-push circuit Amount.By setting the switch discharge circuit being connected with on-off circuit, caused electricity after being turned off every time on on-off circuit is entered Row release, it is thus possible to reduce the energy stored after on-off circuit turns off every time, reduce on-off circuit and generated heat due to energy storage Possibility, improves the service life of on-off circuit, additionally it is possible to reduce the electricity stored on on-off circuit to on-off circuit The follow-up performance cut-off caused influence, improve the inverse-excitation type switch power-supply circuit.
2nd, inverse-excitation type switch power-supply circuit provided by the invention, electrical energy conversion circuit include input circuit, transformer circuit And output circuit；The input of transformer circuit is connected with the output end of the output end of input circuit and on-off circuit, becomes The output end of transformer circuits is connected with the input of output circuit；Inverse-excitation type switch power-supply circuit also includes start-up circuit, opens The input of dynamic circuit is connected with the output end of input circuit, the output end of start-up circuit and the input of pwm control circuit It is connected；Start-up circuit is used for when inverse-excitation type switch power-supply circuit starts, and is powered to pwm control circuit.By set with it is defeated Enter the start-up circuit that circuit and pwm control circuit are connected, realize when the inverse-excitation type switch power-supply circuit just starts, from defeated Enter direct power taking at the signal after processing of circuit to power to pwm control circuit, solve inverse-excitation type switch power-supply circuit and just start When, transformer circuit can not power, it is necessary to the problem of external power supply to pwm control circuit, simplify circuit structure.
3rd, inverse-excitation type switch power-supply circuit provided by the invention, pwm control circuit include：Preferred circuit, feedback circuit and Pwm chip；The input of preferred circuit is connected with the output end of output circuit, output end and the output electricity of preferred circuit The input on road and the input of feedback circuit are connected；Preferred circuit is used for the voltage of stabilizing output circuit, and will output The magnitude of voltage of circuit is sent to feedback circuit；The output end of feedback circuit is connected with the input of pwm chip；Feedback electricity Road is used to the magnitude of voltage of output circuit feeding back to pwm chip.By setting preferred circuit, it is capable of stabilizing output circuit Output voltage, the performance of the inverse-excitation type switch power-supply circuit is improved, meanwhile, preferred circuit is by feedback circuit by output circuit The situation of change of magnitude of voltage feeds back to pwm chip so that pwm chip can produce opposite according to the situation of change Change, the ON time of transformer circuit is adjusted, so as to which the magnitude of voltage of output circuit is adjusted into pre-set output voltage value.
4th, inverse-excitation type switch power-supply circuit provided by the invention, input circuit include ripple filter circuit, ripple filtered electrical Road includes：3rd electric capacity C3 and the 7th resistance R7；3rd electric capacity C3 one end is connected with fire line terminal, the other end and zero line side Son is connected, and the 7th resistance R7 is in parallel with the 3rd electric capacity C3.By on the 3rd electric capacity C3 in ripple filter circuit and being combined In the 7th resistance R7 of partial pressure, the breakdown possibilities of the 3rd electric capacity C3 can be reduced, improve the 3rd electric capacity C3 service life.
Brief description of the drawings
, below will be to specific in order to illustrate more clearly of the specific embodiment of the invention or technical scheme of the prior art The required accompanying drawing used is briefly described in embodiment or description of the prior art, it should be apparent that, in describing below Accompanying drawing is some embodiments of the present invention, for those of ordinary skill in the art, before creative work is not paid Put, other accompanying drawings can also be obtained according to these accompanying drawings.
Fig. 1 is a kind of structural representation of inverse-excitation type switch power-supply circuit provided in an embodiment of the present invention；
Fig. 2 is the structural representation of electrical energy conversion circuit in a kind of inverse-excitation type switch power-supply circuit provided in an embodiment of the present invention Figure；
Fig. 3 is a kind of circuit diagram of inverse-excitation type switch power-supply circuit provided in an embodiment of the present invention；
Fig. 4 is the structural representation of pwm control circuit in a kind of inverse-excitation type switch power-supply circuit provided in an embodiment of the present invention Figure；
Description of reference numerals：
1- electrical energy conversion circuits；11- input circuits；12- transformer circuits；13- output circuits；
2-PWM control circuits；21- preferred circuits；22- feedback circuits；23-PWM control chips；
3- on-off circuits；4- switch discharge circuits；5- start-up circuits.
Embodiment
Technical scheme is clearly and completely described below in conjunction with accompanying drawing, it is clear that described implementation Example is part of the embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the present invention, ordinary skill The every other embodiment that personnel are obtained under the premise of creative work is not made, belongs to the scope of protection of the invention.
In the description of the invention, it is necessary to which explanation, unless otherwise clearly defined and limited, term " connected ", " connects Connect " it should be interpreted broadly, for example, it may be being fixedly connected or being detachably connected, or it is integrally connected；It can be machine Tool connects or electrical connection；Can be joined directly together, can also be indirectly connected by intermediary, can also be two The connection of element internal, can be wireless connection or wired connection.For the ordinary skill in the art, The concrete meaning of above-mentioned term in the present invention can be understood with concrete condition.In addition, term " first ", " second " etc. are only used for retouching Purpose is stated, and it is not intended that instruction or hint relative importance.
As long as in addition, technical characteristic involved in invention described below different embodiments non-structure each other It is be combined with each other into conflict can.
A kind of inverse-excitation type switch power-supply circuit is present embodiments provided, as shown in figure 1, including：Electrical energy conversion circuit 1, PWM Control circuit 2, on-off circuit 3 and switch discharge circuit 4；The output end phase of the input of on-off circuit 3 and pwm control circuit 2 Connection, the output end of on-off circuit 3 are connected with the input of electrical energy conversion circuit 1, and the input of switch discharge circuit 4 is with opening The output end on powered-down road 3 is connected, and the output end of switch discharge circuit 4 is connected with the input of pwm control circuit 2；Switch The control signal that circuit 3 is used to be sent according to pwm control circuit 2 controls the break-make of electrical energy conversion circuit 1；Switch discharge circuit 4 Caused electricity is turned off for release-push circuit 3.
Inverse-excitation type switch power-supply circuit in the present embodiment, by setting the switch discharge being connected with on-off circuit 3 electricity Road 4, caused electricity after being turned off every time on on-off circuit 3 is discharged, it is thus possible to after reducing each shut-off of on-off circuit 3 The energy of storage, reduce the possibility that on-off circuit 3 is generated heat due to energy storage, improve the service life of on-off circuit 3, this Outside, additionally it is possible to reduce the electricity that is stored on on-off circuit 3 it is follow-up on on-off circuit 3 cut-off caused influence, it is anti-to improve this The performance of excitation type switch power-supply circuit.
In the present embodiment, as shown in Fig. 2 electrical energy conversion circuit 1 includes：Input circuit 11, transformer circuit 12 and defeated Go out circuit 13；The input of transformer circuit 12 is connected with the output end of input circuit 11 and the output end of on-off circuit 3, The output end of transformer circuit 12 is connected with the input of output circuit 13.In the present embodiment, input circuit 11 includes：Peace Full protection circuit, shaping circuit and filter circuit, the input of safety protective circuit are connected with input power, safeguard protection electricity The output end on road is connected with the input of shaping circuit；The output end of shaping circuit is connected with the input of filter circuit； The output end of filter circuit is connected with transformer circuit 12.
In a particular embodiment, safety protective circuit can be fusible link, gas-discharge tube (Gas Discharge Tube, GDT), transient voltage suppressor (TransientVoltage Suppressor, TVS), EMI FILTER, One or more in thermistor or piezo-resistance etc., specifically, the set-up mode of safety protective circuit can be according to reality The demand of border application scenarios determines.
In a particular embodiment, shaping circuit can be anti-reverse diode, half-wave rectifier bridge or full-wave rectification bridge, have Body, when input power is direct current, shaping circuit can not connect, take over control reversal connection diode or connect full-wave rectification bridge, when When input power is alternating current, shaping circuit can be half-wave rectifier bridge or full-wave rectification bridge.In a particular embodiment, filter Circuit includes ripple filter circuit, and/or differential mode filter circuit, and/or common mode filtering circuit, specifically, differential mode filter circuit Can be filter capacitor, common mode filtering circuit can be common-mode filter.In a particular embodiment, as shown in figure 3, ripple filters Circuit includes：3rd electric capacity C3 and the 7th resistance R7；3rd electric capacity C3 one end is connected with fire line terminal, the other end and zero line Terminal is connected, and the 7th resistance R7 is in parallel with the 3rd electric capacity C3, and specifically, the 3rd electric capacity C3 can be one or more series connection Electric capacity, when the 3rd electric capacity C3 is the electric capacity of multiple series connection, the 7th resistance R7 and the 3rd electric capacity C3 is correspondingly arranged, i.e., and each 3rd Electric capacity C3 both ends are parallel with the 7th resistance R7.Partial pressure is used for by parallel connection on the 3rd electric capacity C3 in ripple filter circuit 7th resistance R7, the breakdown possibilities of the 3rd electric capacity C3 can be reduced, improve the 3rd electric capacity C3 service life.
In the present embodiment, as shown in figure 4, pwm control circuit 2 includes：Preferred circuit 21, feedback circuit 22 and PWM controls Coremaking piece 23；The input of preferred circuit 21 is connected with the output end of output circuit 13, the output end of preferred circuit 21 with it is defeated The input of the input and feedback circuit 22 that go out circuit 13 is connected；Preferred circuit 21 is used for the electricity of stabilizing output circuit 13 Pressure, and the magnitude of voltage of output circuit 13 is sent to feedback circuit 22；The output end of feedback circuit 22 and pwm chip 23 Input is connected；Feedback circuit 22 is used to the magnitude of voltage of output circuit 13 feeding back to pwm chip 23.
Inverse-excitation type switch power-supply circuit in the present embodiment, being capable of stabilizing output circuit 13 by setting preferred circuit 21 Output voltage, improve the performance of the inverse-excitation type switch power-supply circuit, meanwhile, preferred circuit 21 will be exported by feedback circuit 22 The situation of change of the magnitude of voltage of circuit 13 feeds back to pwm chip 23 so that pwm chip 23 can be according to the change feelings Condition produces opposite change, adjusts the ON time of transformer circuit 12, so as to which the magnitude of voltage of output circuit 13 is adjusted For pre-set output voltage value.
In a particular embodiment, as shown in figure 3, preferred circuit 21 includes：Reference voltage source U1, the 5th resistance R5 and the 6th Resistance R6；Reference voltage source U1 the first pin is connected with feedback circuit 22, second pin and the 6th resistance R6 and ground wire phase Connection, the 3rd pin are connected with the 6th resistance R6 other end and the 5th resistance R5；The 5th resistance R5 other end with it is defeated Go out circuit 13 to be connected.
In a particular embodiment, as shown in figure 3, feedback circuit 22 includes：Resistance R8, resistance R9, optocoupler U3 and electric capacity C4； Resistance R8 one end is connected with output circuit 13, and the resistance R8 other end is connected with the first pin of resistance R9 and optocoupler； The resistance R9 other end is connected with the second pin of optocoupler and reference voltage source U1 the first pin；Electric capacity C4 one end with 8th pin of pwm chip 23 and optocoupler U3 the 3rd pin are connected, electric capacity C4 other end ground connection；Optocoupler U3's 4th pin is grounded.In the present embodiment, optocoupler U3 the first pin, the anode of light emitting diode in optocoupler U3 is referred to；Optocoupler U3 second pin, refer to the negative electrode of light emitting diode in optocoupler U3；Optocoupler U3 the 3rd pin, refer to photosensitive three in optocoupler U3 The colelctor electrode of level pipe；Optocoupler U3 the 4th pin, refer to the emitter stage of photosensitive triode in optocoupler U3.By setting the feedback electric Road 22 so that when the voltage rise in output circuit 13, the electric current for flowing through optocoupler U3 increases, and the 8th of pwm chip 23 the Voltage at pin reduces, and the output duty cycle of pwm chip 23 reduces, i.e., the ON time of transformer circuit 12 shortens, So as to make the magnitude of voltage of output circuit 13 reduce, realize the magnitude of voltage of output circuit 13 being adjusted to pre-set output voltage value.
In the present embodiment, as shown in figure 3, on-off circuit 3 is MOSFET pipe Q1, in a particular embodiment, MOSFET pipes Q1 grid is connected with the 4th pin of pwm chip 23, MOSFET pipes Q1 drain electrode and the primary of transformer circuit 12 Winding is connected, MOSFET pipes Q1 source ground.
In the present embodiment, as shown in figure 3, switch discharge circuit 4 includes：First resistor R1 and the first diode D1；The One resistance R1 one end is connected with MOSFET pipes Q1 grid, and the other end is connected with the first diode D1 anode；First Diode D1 negative electrode is connected with pwm control circuit 2, specifically, the first diode D1 negative electrode and pwm chip 23 4th pin is connected, when first resistor R1 is used to discharge MOSFET pipes Q1 shut-offs, the integrated electricity on MOSFET pipes Q1 grid Hold, prevent MOSFET pipes Q1 from generating heat, meanwhile, MOSFET pipes Q1 is exported normal square wave；First diode D1 is anti-reverse two Pole pipe.In a particular embodiment, switch discharge circuit 4 also includes：Second resistance R2 and 3rd resistor R3；The one of second resistance R2 End is connected with first resistor R1 and MOSFET pipe Q1 grid, the other end and the first diode D1 negative electrode and PWM control Circuit 2 is connected；3rd resistor R3 one end is connected with second resistance R2, first resistor R1 and MOSFET pipe Q1 grid, 3rd resistor R3 other end ground connection, specifically, the second resistance R2 other end and the first diode D1 negative electrode and PWM control 4th pin of coremaking piece 23 is connected, and second resistance R2 and 3rd resistor R3 are used to aid in first resistor R1 release MOSFET pipes Integrated capacitance on Q1 grid, meanwhile, when MOSFET pipes Q1 is in the conduction state, second resistance R2 can also play current limliting Effect, for reducing the excessive possibility for causing MOSFET pipes Q1 breakdown of the electric current on MOSFET pipes Q1.
In an alternate embodiment of the invention, as shown in Figure 2 and Figure 4, inverse-excitation type switch power-supply circuit also includes start-up circuit 5, opens The input of dynamic circuit 5 is connected with the output end of input circuit 11, and the output end of start-up circuit 5 is defeated with pwm control circuit 2 Enter end to be connected；Start-up circuit 5 is used for when inverse-excitation type switch power-supply circuit starts, and is powered to pwm control circuit 2.
Inverse-excitation type switch power-supply circuit in the present embodiment, by setting and input circuit 11 and the phase of pwm control circuit 2 The start-up circuit 5 of connection, realize when the inverse-excitation type switch power-supply circuit just starts, at the signal after the processing of input circuit 11 Direct power taking is powered to pwm control circuit 2, and when solving inverse-excitation type switch power-supply circuit and just starting, transformer circuit 12 can not Powered to pwm control circuit 2, it is necessary to the problem of external power supply, simplify circuit structure.And work as the inverse-excitation type switch power-supply circuit After startup, then powered by the armature winding bio-occlusion pwm control circuit 2 in transformer circuit 12.
In a particular embodiment, as shown in figure 3, start-up circuit 5 includes：4th resistance R4, the first electric capacity C1 and the second electricity Hold C2；4th resistance R4 one end is connected with input circuit 11, and the other end and the first electric capacity C1, the second electric capacity C2 and PWM are controlled Circuit 2 processed is connected；First electric capacity C1 and the second electric capacity C2 other end are grounded, specifically, the 4th resistance R4 one end with The 3rd electric capacity C3 in ripple filter circuit is connected, the 4th resistance R4 other end and the first electric capacity C1, the second electric capacity C2 and The second pin of pwm chip 23 is connected.
Obviously, above-described embodiment is only intended to clearly illustrate example, and is not the restriction to embodiment.It is right For those of ordinary skill in the art, can also make on the basis of the above description it is other it is various forms of change or Change.There is no necessity and possibility to exhaust all the enbodiments.And the obvious change thus extended out or Among changing still in protection scope of the present invention.

Claims (9)

  1. A kind of 1. inverse-excitation type switch power-supply circuit, it is characterised in that including：Electrical energy conversion circuit (1), pwm control circuit (2), On-off circuit (3) and switch discharge circuit (4)；
    The input of the on-off circuit (3) is connected with the output end of the pwm control circuit (2), the on-off circuit (3) Output end be connected with the input of the electrical energy conversion circuit (1)；The input of the switch discharge circuit (4) with it is described The output end of on-off circuit (3) is connected, and the output end of the switch discharge circuit (4) is defeated with the pwm control circuit (2) Enter end to be connected；
    The control signal that the on-off circuit (3) is used to be sent according to the pwm control circuit (2) controls the electric energy to change electricity The break-make on road (1)；The switch discharge circuit (4) is used to discharge electricity caused by the on-off circuit (3) shut-off.
  2. 2. inverse-excitation type switch power-supply circuit according to claim 1, it is characterised in that
    The on-off circuit (3) is MOSFET pipes Q1；The switch discharge circuit (4) includes：First resistor R1 and the one or two pole Pipe D1；
    One end of the first resistor R1 is connected with the grid of the MOSFET pipes Q1, the other end and the first diode D1 Anode be connected；
    The negative electrode of the first diode D1 is connected with the pwm control circuit (2).
  3. 3. inverse-excitation type switch power-supply circuit according to claim 2, it is characterised in that the switch discharge circuit (4) is also Including：
    Second resistance R2, one end of the second resistance R2 are connected with the first resistor R1 and the MOSFET pipes Q1 grid Connect, the other end is connected with the negative electrode and the pwm control circuit (2) of the first diode D1.
  4. 4. inverse-excitation type switch power-supply circuit according to claim 3, it is characterised in that the switch discharge circuit (4) is also Including：
    3rd resistor R3, one end of the 3rd resistor R3 and the second resistance R2, the first resistor R1 and described MOSFET pipes Q1 grid is connected, the other end ground connection of the 3rd resistor R3.
  5. 5. according to the inverse-excitation type switch power-supply circuit described in claim any one of 1-4, it is characterised in that
    The electrical energy conversion circuit (1) includes input circuit (11), transformer circuit (12) and output circuit (13)；
    The input of the transformer circuit (12) and the output end of the input circuit (11) and the on-off circuit (3) Output end is connected, and the output end of the transformer circuit (12) is connected with the input of the output circuit (13)；
    The inverse-excitation type switch power-supply circuit also includes start-up circuit (5), input and the input of the start-up circuit (5) The output end of circuit (11) is connected, the output end and the input phase of the pwm control circuit (2) of the start-up circuit (5) Connection；The start-up circuit (5) is used for when the inverse-excitation type switch power-supply circuit starts, and is supplied to the pwm control circuit (2) Electricity.
  6. 6. inverse-excitation type switch power-supply circuit according to claim 5, it is characterised in that
    The start-up circuit (5) includes：4th resistance R4, the first electric capacity C1 and the second electric capacity C2；
    One end of the 4th resistance R4 is connected with the input circuit (11), the other end and the first electric capacity C1, described Second electric capacity C2 is connected with the pwm control circuit (2)；
    The first electric capacity C1 and the second electric capacity C2 other end are grounded.
  7. 7. inverse-excitation type switch power-supply circuit according to claim 6, it is characterised in that
    The pwm control circuit (2) includes：Preferred circuit (21), feedback circuit (22) and pwm chip (23)；
    The input of the preferred circuit (21) is connected with the output end of the output circuit (13), the preferred circuit (21) Output end be connected with the input of the output circuit (13) and the input of the feedback circuit (22)；The standard Circuit (21) is used for the voltage for stablizing the output circuit (13), and the magnitude of voltage of the output circuit (13) is sent to described Feedback circuit (22)；
    The output end of the feedback circuit (22) is connected with the input of the pwm chip (23)；The feedback circuit (22) it is used to the magnitude of voltage of the output circuit (13) feeding back to the pwm chip (23).
  8. 8. inverse-excitation type switch power-supply circuit according to claim 7, it is characterised in that
    The preferred circuit (21) includes：Reference voltage source U1, the 5th resistance R5 and the 6th resistance R6；
    The first pin of the reference voltage source U1 is connected with the feedback circuit (22), second pin and the 6th resistance R6 is connected with ground wire, and the 3rd pin is connected with the other end of the 6th resistance R6 and the 5th resistance R5；
    The other end of the 5th resistance R5 is connected with the output circuit (13).
  9. 9. inverse-excitation type switch power-supply circuit according to claim 8, it is characterised in that
    The input circuit (11) includes ripple filter circuit, and the ripple filter circuit includes：The electricity of 3rd electric capacity C3 and the 7th Hinder R7；
    One end of the 3rd electric capacity C3 is connected with fire line terminal, and the other end is connected with zero terminal；7th resistance R7 is in parallel with the 3rd electric capacity C3.
CN201711463574.2A 2017-12-28 2017-12-28 A kind of inverse-excitation type switch power-supply circuit Pending CN107888066A (en)

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CN201711463574.2A CN107888066A (en) 2017-12-28 2017-12-28 A kind of inverse-excitation type switch power-supply circuit

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Application Number Priority Date Filing Date Title
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040032754A1 (en) * 2002-08-19 2004-02-19 Jian Yang Multiple output power supply having soft start protection for load over-current or short circuit conditions
CN203071821U (en) * 2012-12-26 2013-07-17 昂宝电子（上海）有限公司 Flyback switch power supply circuit
CN203289341U (en) * 2013-01-07 2013-11-13 昂宝电子（上海）有限公司 Flyback switch power supply circuit
CN104184331A (en) * 2014-08-11 2014-12-03 苏州汇川技术有限公司 Flyback switching power supply
CN204156745U (en) * 2014-08-19 2015-02-11 千江（上海）信息科技有限公司 Inverse-excitation type multi-output switch power source
CN204392106U (en) * 2015-02-06 2015-06-10 深圳市新港源技术有限公司 Switching power supply
CN207638553U (en) * 2017-12-28 2018-07-20 浙江正泰仪器仪表有限责任公司 A kind of inverse-excitation type switch power-supply circuit

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040032754A1 (en) * 2002-08-19 2004-02-19 Jian Yang Multiple output power supply having soft start protection for load over-current or short circuit conditions
CN203071821U (en) * 2012-12-26 2013-07-17 昂宝电子（上海）有限公司 Flyback switch power supply circuit
CN203289341U (en) * 2013-01-07 2013-11-13 昂宝电子（上海）有限公司 Flyback switch power supply circuit
CN104184331A (en) * 2014-08-11 2014-12-03 苏州汇川技术有限公司 Flyback switching power supply
CN204156745U (en) * 2014-08-19 2015-02-11 千江（上海）信息科技有限公司 Inverse-excitation type multi-output switch power source
CN204392106U (en) * 2015-02-06 2015-06-10 深圳市新港源技术有限公司 Switching power supply
CN207638553U (en) * 2017-12-28 2018-07-20 浙江正泰仪器仪表有限责任公司 A kind of inverse-excitation type switch power-supply circuit

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