CN103023289A - Indifference output power switching circuit with load protection - Google Patents

Indifference output power switching circuit with load protection Download PDF

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CN103023289A
CN103023289A CN2012105170739A CN201210517073A CN103023289A CN 103023289 A CN103023289 A CN 103023289A CN 2012105170739 A CN2012105170739 A CN 2012105170739A CN 201210517073 A CN201210517073 A CN 201210517073A CN 103023289 A CN103023289 A CN 103023289A
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circuit
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input
resistance
vmos
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CN103023289B (en
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胡家培
胡民海
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Xian Zhihai Power Technology Co Ltd
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Xian Zhihai Power Technology Co Ltd
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Abstract

The invention provides an indifference output power switching circuit with load protection. The circuit is based on a BOOST structure and comprises a pulse width modulation (PWM) control circuit, an input current sampling circuit, an output current sampling circuit, a drive signal synthesis circuit and a V Groove Metal Oxide Semiconductor (VMOS) switching circuit, wherein output ends of the input current sampling circuit and the output current sampling circuit are connected to the input end of the VMOS switching circuit through a width modulated pulse control circuit, the drive signal synthesis circuit and a VMOS switching drive circuit, and the output end of the VMOS switching circuit is connected to the load through a reverse isolation circuit, a storage filter circuit and an output protection circuit. By the aid of the circuit, the indifference directional direct current output of multiwave input can be achieved, the BOOST output can be adjusted automatically when the load shorts circuit, the limiting output is achieved and the low power consumption is guaranteed.

Description

Indifference out-put supply change-over circuit with load protection
Technical field
The present invention relates to a kind of power-switching circuit with load protection.
Background technology
In recent years, the renewable new energy resources system of the AC low-tensions such as photovoltaic generation, wind power generation, storage battery power supply, dc low-voltage power supply is widely used, and the power supplying efficiency, power supply quality, the power supply reliability that improve low pressure new energy system are imperative.
The basic employing of present power supply conversion known in this field:
1, exchange (AC) input, adopting full-wave rectifier is input AC (AC) power rectifier direct current (DC) power supply, carries out DC/DC again and is converted to direct current (DC) output.This kind solution the transfer problem of high-line input voltage AC power and small-power power.But when the input of low-voltage AC power supply and large power supply conversion, because the voltage drop of AC/DC rectification circuit is higher, and produce very high power consumption, make the power supply changeover device conversion efficiency very low.
2, direct current (DC) input is directly carried out DC/DC and is converted to direct current (DC) output.This kind solution the permanent plant powerup issue.But dependability is lower, especially at mobility equipment, often need to reconnect the equipment of input power, connects anti-situation in case electric power polarity occurs, will produce the input short accident.Therefore the higher equipment of ask for something reliability adds the directed rectification circuit of direct current at the transducer input.When the straight power supply input of low-voltage and large power supply conversion, higher because direct current is identified the voltage drop of directed rectification circuit, and produce very high power consumption, make the power supply changeover device conversion efficiency very low.
3, in order to improve low-voltage power supply efficient, to reduce line current and generally adopt boost type (BOOST) direct current (DC) supply power mode.Boost type (BOOST) direct current (DC) power supply is when output generation short trouble, and the BOOST circuit function lost efficacy when output voltage was lower than input voltage, and input power is directly to load short circuits, and large electric current (high-power) system short-circuit protection control difficulty is very large.
Describe as example being input as low pressure new forms of energy power supply take conventional rectification (identification directed) circuit, input voltage Ui=10V (AC, DC), input current Ii=20A, input power Pi=10 * 20=200W, rectification (identification is directed) circuit pressure drop Ud=2V, rectification (identification is directed) circuit consumption is: Pd=2 * 20=40W, power output Po=200-40=160W, its rectification (identification is directed) efficient is: E=160/200=0.8, this shows that conventional rectification (identification is directed) circuit is when being input as low pressure new forms of energy power supply, power consumption is very large, and efficient is very low.
Summary of the invention
The invention provides a kind of indifference out-put supply change-over circuit with load protection, solved mainly that existing low pressure new forms of energy power supply changeover device power consumption is high, efficient is low, the problem of poor reliability.
Concrete technical solution of the present invention is as follows:
Should be with the indifference out-put supply change-over circuit of load protection, comprise input current sample circuit and output current sample circuit, the input of described input current sample circuit is connected with the output of input power, the input of output current sample circuit be connected input with output protection circuit and be connected, the output of input current sample circuit and output current sample circuit is all successively by the width modulation type pulse control circuit, drive signal synthesis circuit, the VMOS switch driving circuit is connected with the input of VMOS switching circuit, the input of described VMOS switching circuit also is connected with the output of input power by the afterflow inductance, and the output of VMOS switching circuit is successively by the reverse isolation circuit, the energy storage filter circuit, output protection circuit is connected with load; The output of VMOS switching circuit also is connected with the input that drives signal synthesis circuit by the afterflow voltage sampling circuit; Described width modulation type pulse control circuit, driving signal synthesis circuit, VMOS switch driving circuit and afterflow voltage sampling circuit composition control circuit;
Described afterflow inductance is arranged on the symmetrical inductance of differential mode on the input power output anode; Described VMOS switch driving circuit comprises the driver of two parallel connections, and each driver is connected with the input of two VMOS pipe groups respectively;
Described output protection circuit comprises reference voltage source, comparator A, comparator B, triode N1 and voltage-stabiliser tube Z5; The input termination BOOST VD of this output safety control circuit, the load of output termination, series connection is provided with VMOS pipe M5 and current-limiting resistance R24 on the major loop at described input and output place, wherein, the base stage of VMOS pipe M5 is connected to the negative terminal of described output through triode N1, and the base stage of triode N1 is connected to described reference voltage source; Described output is parallel with a filter capacitor and a feedback branch, is in series with successively divider resistance R14 and RC circuit on this feedback branch;
The normal phase input end of comparator A accesses this feedback branch, be connected to the anode of described output through divider resistance R14, the negative-phase input of comparator A connects reference voltage, and the output of comparator A is connected to the negative terminal of described input successively through resistance R 13, resistance R 27, the resistance R 22 of series connection;
The series arm at normal phase input end access resistance R 13, resistance R 27 and resistance R 22 places of comparator B, its access node is between resistance R 27 and resistance R 22; The negative-phase input of comparator B is connected to the negative terminal of described output through resistance R 6; The output of comparator B is connected to the base stage of triode N1.
Based on such scheme, the present invention can also do following optimization and limit and improve:
Described driving signal synthesis circuit is standard two input or gate control chips, and this control chip comprises four couples of input A1, A2, B 1, B2, C1, C2, D1, D2 and corresponding four output terminals A o, Bo, Co, Do, input A1 wherein, B1, C1, D1 is connected input A2, B2 with two outputs of width modulation type pulse control circuit, C2, D2 is connected with two outputs of afterflow voltage sampling circuit, and output terminals A o, Bo, Co, Do are connected with the input of VMOS switch driving circuit.
Described width modulation type pulse control circuit is the PWM controller of inverse-excitation type control, and two output terminals A o, Bo of PWM controller are connected to respectively the one group of input that drives signal synthesis circuit.
Described input current sample circuit comprises current sensor CS1, capacitor C 13, resistance R 21, and diode D4, current sensor CS1 connect with diode D4 and consist of a branch road, capacitor C 13, resistance R 21 respectively with this branch circuit parallel connection.
Described output current sample circuit comprises current sensor CS2, capacitor C 9 and diode D5, and current sensor CS2 connects with diode D5 and consists of a branch road, capacitor C 9 and this branch circuit parallel connection.
Described afterflow voltage sampling circuit comprises by voltage stabilizing didoe Z3, filter capacitor C11, divider resistance R3, the output sample circuit that R4 forms and by voltage stabilizing didoe Z4, filter capacitor C12, divider resistance R1, the input sampling circuit that R5 forms, the output of described output sample circuit is the node between R4 and the R3, this node is connected with an interface that drives the signal synthesis circuit input, the output of input sampling circuit is the node between R1 and the R5, and this node is connected with another interface that drives the signal synthesis circuit input.
The invention has the advantages that:
Indifference out-put supply change-over circuit with load protection provided by the invention has XC/DC expansion (XC) shape, nonpolarity, many waveforms, the input of broadband power supply; DC (direct current) output, the advantages such as auto polarity identification orientation, high conversion efficiency, High Power Factor, high reliability, high power density, low cost.
Added output protection circuit can guarantee that BOOST output adjusts automatically when load short circuits, current limliting output still guarantees low-power consumption simultaneously.
Description of drawings
Fig. 1 is schematic block circuit diagram of the present invention;
Fig. 2 is electrical block diagram of the present invention;
Fig. 3 is automatic orientation BOOST electric current flow graph when the positive half cycle of Ui (M1, M2, M3, M4) PWM conducting;
Fig. 4 is automatic orientation BOOST electric current flow graph when the positive half cycle of Ui (M3, M4) PWM conducting afterflow;
Fig. 5 is that input power is the monocycle oscillogram of Ac when sinusoidal wave.
Fig. 6 is the structural representation of output protection circuit of the present invention.
Embodiment
Should be with the indifference out-put supply change-over circuit of load protection, comprise input current sample circuit and output current sample circuit, the input of described input current sample circuit is connected with the output of input power, the input of output current sample circuit is connected with the input of load, the output of input current sample circuit and output current sample circuit is all successively by the width modulation type pulse control circuit, drive signal synthesis circuit, the VMOS switch driving circuit is connected with the input of VMOS switching circuit, the input of described VMOS switching circuit also is connected with the output of input power by the afterflow inductance, and the output of VMOS switching circuit is successively by the reverse isolation circuit, the energy storage filter circuit is connected with load; The output of VMOS switching circuit also is connected with the input that drives signal synthesis circuit by the afterflow voltage sampling circuit; Described width modulation type pulse control circuit, driving signal synthesis circuit, VMOS switch driving circuit and afterflow voltage sampling circuit composition control circuit; Described afterflow inductance is arranged on the symmetrical inductance of differential mode on the input power output anode; Described VMOS switch driving circuit comprises the driver of two parallel connections, and each driver is connected with the input of two VMOS pipe groups respectively.
Driving signal synthesis circuit is standard two input or gate control chips, and this control chip comprises four couples of input A1, A2, B1, B2, C1, C2, D1, D2 and corresponding four output terminals A o, Bo, Co, Do, input A1 wherein, B1, C1, D1 is connected input A2, B2 with two outputs of width modulation type pulse control circuit, C2, D2 is connected with two outputs of afterflow voltage sampling circuit, and output terminals A o, Bo, Co, Do are connected with the input of VMOS switch driving circuit.
The width modulation type pulse control circuit is the PWM controller of inverse-excitation type control, and two output terminals A o, Bo of PWM controller are connected to respectively the one group of input that drives signal synthesis circuit.
The input current sample circuit comprises current sensor CS1, capacitor C 13, resistance R 21, and diode D4, current sensor CS1 connect with diode D4 and consist of a branch road, capacitor C 13, resistance R 21 respectively with this branch circuit parallel connection.
The output current sample circuit comprises current sensor CS2, capacitor C 9 and diode D5, and current sensor CS2 connects with diode D5 and consists of a branch road, capacitor C 9 and this branch circuit parallel connection.
The afterflow voltage sampling circuit comprises by voltage stabilizing didoe Z3, filter capacitor C11, divider resistance R3, the output sample circuit that R4 forms and by voltage stabilizing didoe Z4, filter capacitor C12, divider resistance R1, the input sampling circuit that R5 forms, the output of described output sample circuit is the node between R4 and the R3, this node is connected with an interface that drives the signal synthesis circuit input, the output of input sampling circuit is the node between R1 and the R5, and this node is connected with another interface that drives the signal synthesis circuit input.
Below the function of each Important Circuit is described:
Afterflow inductance: utilize inductance characteristic that input power is boosted;
VMOS switching circuit: VMOS switching circuit conduction period, have electric current to pass through in the afterflow inductance; VMOS switching circuit blocking interval, the freewheeling circuit conducting makes electric current continuation conducting in the afterflow inductance, produces high pressure, and the energy storage filter circuit is charged, and by the energy storage filter circuit load is powered after the charging;
Energy storage filter circuit: VMOS switching circuit blocking interval charging and to load supplying;
VMOS switch driving circuit: VMOS switching signal and the VMOS afterflow signal that drives the signal synthesis circuit generation amplified processing;
Drive signal synthesis circuit: the PWM width modulation type pulse signal of width modulation type pulse control circuit generation, alternating current-direct current signal, both positive and negative polarity signal or afterflow signal and the power supply signal of voltage sampling circuit input are synthesized, generate composite signal (comprising polarity, interchange, direct current, accent bandwidth signals); Then automatically distribute according to composite signal, divide into VMOS switching signal and VMOS afterflow signal;
The width modulation type pulse control circuit: the current sampling signal according to input sampling circuit and/or the input of output sample circuit generates PWM width modulation type pulse signal;
The afterflow voltage sampling circuit: the current signal to VMOS switching circuit and freewheeling circuit is sampled, and produces alternating current-direct current signal, both positive and negative polarity signal or afterflow signal, and above-mentioned signal is inputed to the driving signal synthesis circuit;
The input current sample circuit: input is sampled through the electric current of afterflow inductance to input power, generates sampled signal and sampled signal is offered the width modulation type pulse control circuit and process;
Below in conjunction with accompanying drawing the present invention is described in detail:
IC1 (UCC28084 or other similar device), for the standard both-end is alternately exported the PWM controller, PWM transfers wide output by device 1 end (OC) control, output alternative P WM waveform P1, P2.
R1, R5, C12, Z4 detect shaping to afterflow waveform PA, form waveform P3.Wherein, voltage-stabiliser tube Z4 keeps the voltage stabilization of P3, and capacitor C 12 is in order to filtering, so that can make P3 continue high level when high level appears in PA.
R4, R3, C11, Z3 detect shaping to afterflow waveform PB, form waveform P4.Wherein, voltage-stabiliser tube Z3 keeps the voltage stabilization of P4, and capacitor C 11 is in order to filtering, so that can make P4 continue high level when high level appears in PB.
IC2 (CD4071 or other similar device) is standard 2 inputs or door, wherein: and Ao=A1+A2, Bo=B1+B2, Co=C1+C2, Do=D1+D2, carry out the synthetic rear staggered output pwm waveform that forms of logic to P1, P2, P3, P4.
IC3, IC4 (IR442 or other similar device) are standard drive, wherein: Ao=Ai, Bo=Bi, VMOS is carried out the high speed large driven current density, improve conversion efficiency to reduce VMOS switch power consumption.
CS1, CS2, D4, D5, R21, C13 form current sense, discriminating, testing circuit, the current waveform that the high-end VMOS of power supply passes through when automatically detecting PWM and opening.Super its circuit has very low power consumption simultaneously, adopts current sense coefficient ﹤ 100, controlling of sampling voltage ﹤ 0.5V, and control power consumption Pe ﹤ 0.5 * IO * 0.01=0.005 * IO (IO is On current) is when IO is 20A: Pe ﹤ 0.05 * 20=0.1W.
C7, C8, C9 are mainly used in further eliminating noise (burst pulse).
L1, D3, C14 form the LDC of BOOST booster circuit, in order to adapt to the asymmetry of input power, such as unipolarity direct current, unipolarity square wave, unipolarity triangular wave etc., L1 adopts the differential mode symmetrical expression, also can be only inductance be set as L1 at anode or the negative terminal of input circuit.
Ao port and the Bo port of pwm control circuit (IC1) are alternately exported control signal P1, P2, and total the maintenance blanking time (corresponding to the high level of PA waveform) that is used for afterflow between P1, the P2.P3, P4 are by the PA in the input circuit, PB waveform dividing potential drop gained.The input port of P1, P2, P3, P4 access triggering signal combiner circuit (IC2), carry out foregoing or logical operation after, drive through switch driver IC3, IC4 respectively again triggering signal added to respectively two VMOS switching circuit groups (M1, M2; M3, M4), D3 has two inputs, is connected to respectively anode and the negative terminal of input circuit, and forward current charges to C14 through reverse isolation circuit D3.
M1 alternation in parallel with M2, M3 alternation in parallel with M4 (each VMOS switch itself has diode in parallel with it).
Just lower negative on the positive half cycle of waveform or input direct-current are at input AC, when one of the control signal P1 of pwm control circuit (IC1) output and P2 are in high level, this XC/DC automatic orientation BOOST circuit is in the PWM conducting state, electric current from anode flow through successively first group of VMOS switching circuit group (M1, M2), second group of VMOS switching circuit group (M3, M4), then flows back to negative terminal in input circuit; Because D3 plays the reverse isolation effect, the energy storage on the C14 can reverse flow not be fed back into the loop.
As the control signal P1 of pwm control circuit (IC1) output, when P2 is low level, then there is not triggering signal on M1, the M2, therefore M1, not conducting of M2, but because the existence of afterflow inductance L 1, and the diode among M3, the M4 can form the conducting loop of certainly holding to the input circuit negative terminal, thereby the afterflow that produces because of the afterflow inductance in the circuit is charged to C14 through D3 from the anode of input circuit, and via load, second group of VMOS switching circuit group (M3, M4) of output loop, then flow back to negative terminal simultaneously.In fact, in case there is above-mentioned afterflow in the circuit, namely PA is that high level, PB are low level, thereby so that P1, P2, P3, P4 carry out or logical operation after produce triggering signal, make M3, M4 conducting, because the resistance of M3, M4 is very little, therefore, the power consumption that produces in the afterflow process is still very little.And the output itself of boosting can reduce line loss.Such as, Ui=10 (V), the rear Uo=50 (V) that boosts is then according to P=U 2/ R as can be known, line loss only is original 1/5.
Illustrate low-power consumption of the present invention: adopt R in the circuit DS=0.001 Ω low on-resistance N raceway groove VMOS pipe, the staggered conducting of M1, M2 during PWM opens, VMOS conducting resistance R DS=0.001 Ω, the two-tube paralleling and interleaving conducting of M3, M4, VMOS conducting resistance R DS=0.001 Ω/2=0.0005 Ω, if still input the 20A electric current, then conducting voltage is: U1=0.001 * 20=0.02V, U2=0.0005 * 20=0.01V, identify directed power consumption and be: Pe=20 * (0.02+0.01)=0.6W; End shutoff at PWM blocking interval M1, M2, the two-tube paralleling and interleaving conducting of M3, M4 afterflow, VMOS conducting resistance R DS=0.001 Ω/2=0.0005 Ω, if the 20A freewheel current, then conducting voltage is: U2=0.0005 * 20=0.01V, identify directed power consumption and be: Pe=20 * 0.01=0.2W.Compare to the power consumption of the rectification identification directional circuit 40W of prior art, XC/DC of the present invention automatically identifies directed BOOST circuit power consumption and significantly reduces.
If reverse isolation circuit D3 also adopts synchronous VMOS switching circuit (synchronous waveform of its triggering signal and PA and PB), then can utilize the little characteristic of VMOS switching circuit resistance further to reduce line loss.Especially the raising of conversion efficiency is more remarkable when BOOST output is low.
The VMOS switch is under the triggering signal effect, can realize forward or backwards conducting according to institute's making alive polarity, based on this characteristic, be negative lower timing at input AC at waveform negative half period or input direct-current, the course of work of this XC/DC automatic orientation BOOST circuit and above-mentioned conducting, afterflow Principle of Process are identical, and because first group of VMOS switching circuit group (M1, M2) adopts the symmetric circuit structure with second group of VMOS switching circuit group (M3, M4), be completely reversibility in the VMOS conducting of Ui negative half period and afterflow.Such as, as the control signal P1 of pwm control circuit (IC1) output, when P2 is low level, then do not have triggering signal on M3, the M4, so M3, not conducting of M4, and realize the afterflow process by first group of VMOS switching circuit group (M1, M2).
As seen, this BOOST circuit can be finished the automatic identification of bipolar power supply (exchanging just profound ripple, square wave, triangular wave, AC power frequency, intermediate frequency, low frequency, ultralow frequency) directed automatically; And directed to the automatic identification of unipolarity power supply (direct current, direct current square wave, direct current triangular wave etc.), exchanging bipolar power supply and direct current unipolarity power supply can be regardless of positive and negative any access.
In addition, the output safety control circuit that adds before load comprises reference voltage source, comparator A, comparator B, triode N1 and voltage-stabiliser tube Z5; The input termination BOOST VD of this output safety control circuit, the load of output termination, series connection is provided with VMOS pipe M5 and current-limiting resistance R24 on the major loop at described input and output place, wherein, the base stage of VMOS pipe M5 is connected to the negative terminal of described output through triode N1, and the base stage of triode N1 is connected to described reference voltage source; Described output is parallel with a filter capacitor and a feedback branch, is in series with successively divider resistance R14 and RC circuit on this feedback branch;
The normal phase input end of comparator A accesses this feedback branch, be connected to the anode of described output through divider resistance R14, the negative-phase input of comparator A connects reference voltage, and the output of comparator A is connected to the negative terminal of described input successively through resistance R 13, resistance R 27, the resistance R 22 of series connection;
The series arm at normal phase input end access resistance R 13, resistance R 27 and resistance R 22 places of comparator B, its access node is between resistance R 27 and resistance R 22; The negative-phase input of comparator B is connected to the negative terminal of described output through resistance R 6; The output of comparator B is connected to the base stage of triode N1.
Between the drain electrode of the base stage of VMOS pipe M5 and triode N1, draw a branch road to the source electrode that VMOS manages M5, be provided with voltage-stabiliser tube Z1 on this branch road.
Described reference voltage is by providing with the source-series 2.5V voltage-stabiliser tube of described reference voltage.
The access node of the normal phase input end of comparator B also is connected to the negative terminal of described output by filter capacitor.
Comparator A and comparator B consist of a two encapsulation comparator.
The preferred LH2903 of this pair encapsulation comparator, LM2903 or other similar device.
IC5 is standard high-speed comparator circuit (dual comparator), and comparator B, N1, M5 form constant-current control circuit.B-terminal voltage V3=0V, the B+ terminal voltage is:
V2=R22×V1/(R22+R27)-Us
In the following formula, Us=Is * Rs=Is * R24
V1 voltage is controlled by comparator A, A-terminal voltage VR=2.5V, and the A+ terminal voltage is:
VL=UL×R7/(R7+R14)=RL×Is。
1, current-limited startup
During circuit start (powering on), VL ﹤ 2.5V, comparator A output is low, then R13 access dividing potential drop.
Wherein: R13 ﹤ ﹤ R25, R13 ﹤ ﹤ R27, VR=2.5V;
V1≈VR×R13/(R13+R25)=2.5×R13/(R13+R25)
V2=R22×V1/(R22+R27)-Us=R22×(2.5×R13/(R13+R25))/(R22+R27)-Us
=2.5×R22×R13/((R13+R25)(R22+R27))-Is×Rs
If: c1=2.5 * R22 * R13/ ((R13+R25) (R22+R27))
That is: V2=c1-Rs * Is
When V2=c1-Rs * Is<=0, comparator B, N1, the output of M5 current limliting, cut-off current is: Is=c1/Rs.
Can guarantee that namely BOOST output starts with current limliting (Is=c1/Rs).
VL=UL×R7/(R7+R14)=RL×Is=c1×RL/Rs
Therefore, only need the corresponding resistance of configuration, so that during BOOST load impedance less (short circuit), VL ﹤ 2.5V is operated under the safe limited current state.Such as, according to Is=c1/Rs, Is is set between routine value 1/4-1/10.
2, operating conventional current limliting
Comparator A output high (open circuit) when BOOST load impedance fault-free VL>=2.5V, R13 disengaging dividing potential drop then, V2=2.5 * R22/ (R22+R27+R25)-Us;
If: c2=2.5 * R22/ (R22+R27+R25)
That is: V2=c2-Rs * IL
When V2=c2-Rs * IL<=0, comparator B, N1, the output of M5 current limliting, cut-off current is: IL=c2/Rs,
Can guarantee that namely BOOST output works with current limliting (IL=c2/Rs).
Therefore, only need the corresponding resistance of configuration, make IL greater than running current, and VMOS is limited in the safe range of electric current, power.Usually, IL is set between 1.1 times to 1.5 times of conventional value.
3, the low-power consumption of normal operation
During BOOST output normal operation, output current is less than IL, and comparator (A, B) is exported high (open circuit), and P raceway groove VMOS (M5) is operated in ultralow conducting resistance (R DS=0.005 Ω) under the state.
For example: power output 200W output voltage 50V, then output current is: Io=200/50=4A,
The upper pressure drop of VMOS (M5) is: 4 * 0.005=0.02,
VMOS (M5) control power consumption is: Pe=0.02 * 4=0.08W, can find out that the control power consumption when normally moving is very low.
4, short-circuit protection
If if the fault such as output short-circuit occurs in the BOOST circuit working process, cause VL ﹤ 2.5V, then comparator A output is low, make comparator B, N1, M5 current limliting output (referring to aforementioned the 1st kind of situation), circuit reenters clean boot (Is) state, behind Failure elimination, BOOST recovers normal output automatically.
Above-described embodiment is most preferred embodiment of the present invention, adopts this staggered PWM control mode to make M1, the M2 conducting that interlocks, and each VMOS switch frequency is 1/2 channel frequency, and the VMOS switch is being worked than under the low switching frequency, significantly reduces the switch power consumption; Correspondingly, the operating frequency of L, C device is 2 times of VMOS pipe frequencies in the circuit, and higher circuit work frequency has reduced the requirement to inductance in the lc circuit (L) amount and electric capacity (C), has reduced cost and technology difficulty.In fact, based on the basic principle of conducting of the present invention, afterflow, can consider that also each VMOS switching circuit group only adopts a VMOS switch, also is enough to embody technique effect of the present invention.Such as only keeping M1, M3, equally also can be just lower when negative on the positive half cycle of waveform or input direct-current are at input AC, realize the conducting loop by M1, M3, realize continuous current circuit by M3; Be negative lower timing at input AC at waveform negative half period or input direct-current, realize the conducting loop by M1, M3, realize continuous current circuit by M1.Certainly, under this scheme, also can attempt allowing the operating frequency of each VMOS switch reduce by half, but this just need to increase afterflow inductance, storage capacitor exponentially, satisfying the requirement of afterflow, thereby cause that cost is higher, the components and parts volume is large, power density reduces.

Claims (6)

1. indifference out-put supply change-over circuit with load protection, it is characterized in that: comprise input current sample circuit and output current sample circuit, the input of described input current sample circuit is connected with the output of input power, the input of output current sample circuit be connected input with output protection circuit and be connected, the output of input current sample circuit and output current sample circuit is all successively by the width modulation type pulse control circuit, drive signal synthesis circuit, the VMOS switch driving circuit is connected with the input of VMOS switching circuit, the input of described VMOS switching circuit also is connected with the output of input power by the afterflow inductance, and the output of VMOS switching circuit is successively by the reverse isolation circuit, the energy storage filter circuit, output protection circuit is connected with load; The output of VMOS switching circuit also is connected with the input that drives signal synthesis circuit by the afterflow voltage sampling circuit; Described width modulation type pulse control circuit, driving signal synthesis circuit, VMOS switch driving circuit and afterflow voltage sampling circuit composition control circuit;
Described afterflow inductance is arranged on the symmetrical inductance of differential mode on the input power output anode; Described VMOS switch driving circuit comprises the driver of two parallel connections, and each driver is connected with the input of two VMOS pipe groups respectively;
Described output protection circuit comprises reference voltage source, comparator A, comparator B, triode N1 and voltage-stabiliser tube Z5; The input termination BOOST VD of this output safety control circuit, the load of output termination, series connection is provided with VMOS pipe M5 and current-limiting resistance R24 on the major loop at described input and output place, wherein, the base stage of VMOS pipe M5 is connected to the negative terminal of described output through triode N1, and the base stage of triode N1 is connected to described reference voltage source; Described output is parallel with a filter capacitor and a feedback branch, is in series with successively divider resistance R14 and RC circuit on this feedback branch;
The normal phase input end of comparator A accesses this feedback branch, be connected to the anode of described output through divider resistance R14, the negative-phase input of comparator A connects reference voltage, and the output of comparator A is connected to the negative terminal of described input successively through resistance R 13, resistance R 27, the resistance R 22 of series connection;
The series arm at normal phase input end access resistance R 13, resistance R 27 and resistance R 22 places of comparator B, its access node is between resistance R 27 and resistance R 22; The negative-phase input of comparator B is connected to the negative terminal of described output through resistance R 6; The output of comparator B is connected to the base stage of triode N1.
2. the indifference out-put supply change-over circuit with load protection according to claim 1; it is characterized in that: described driving signal synthesis circuit is standard two input or gate control chips; this control chip comprises four couples of input A1, A2, B1; B2; C1, C2, D1; D2 and corresponding four output terminals A o; Bo; Co; Do; input A1 wherein, B1, C1; D1 is connected with two outputs of width modulation type pulse control circuit; input A2, B2, C2; D2 is connected output terminals A o with two outputs of afterflow voltage sampling circuit; Bo; Co; Do is connected with the input of VMOS switch driving circuit.
3. the indifference out-put supply change-over circuit with load protection according to claim 2; it is characterized in that: described width modulation type pulse control circuit is the PWM controller of inverse-excitation type control, and two output terminals A o, Bo of PWM controller are connected to respectively the one group of input that drives signal synthesis circuit.
4. the indifference out-put supply change-over circuit with load protection according to claim 3; it is characterized in that: described input current sample circuit comprises current sensor CS1, capacitor C 13, resistance R 21; diode D4; current sensor CS1 connects with diode D4 and consists of a branch road, capacitor C 13, resistance R 21 respectively with this branch circuit parallel connection.
5. the indifference out-put supply change-over circuit with load protection according to claim 4; it is characterized in that: described output current sample circuit comprises current sensor CS2, capacitor C 9 and diode D5; current sensor CS2 connects with diode D5 and consists of a branch road, capacitor C 9 and this branch circuit parallel connection.
6. the indifference out-put supply change-over circuit with load protection according to claim 5; it is characterized in that: described afterflow voltage sampling circuit comprises by voltage stabilizing didoe Z3; filter capacitor C11; divider resistance R3; the output sample circuit that R4 forms and by voltage stabilizing didoe Z4; filter capacitor C12; divider resistance R1; the input sampling circuit that R5 forms; the output of described output sample circuit is the node between R4 and the R3; this node is connected with an interface that drives the signal synthesis circuit input, and the output of input sampling circuit is the node between R1 and the R5, and this node is connected with another interface that drives the signal synthesis circuit input.
CN201210517073.9A 2012-11-30 2012-11-30 With the indifference out-put supply change-over circuit of load protection Expired - Fee Related CN103023289B (en)

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Publication number Priority date Publication date Assignee Title
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CN2728096Y (en) * 2004-09-20 2005-09-21 赵树林 FET automotive alternator voltage regulator with multiple protective functions
CN101056068A (en) * 2005-09-12 2007-10-17 快捷半导体有限公司 VRMS and rectified current sense full-bridge synchronous-rectification integrated with PFC
CN101672931A (en) * 2009-09-24 2010-03-17 重庆大学 Unipolar trapezoidal pulse current control method and device of inductive load
CN101713969A (en) * 2009-11-19 2010-05-26 杭州电子科技大学 Anti-clamp circuit of electric skylight

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2466848Y (en) * 2001-01-15 2001-12-19 广东南方通信集团公司 Rectifying module for switching supply unit
CN2728096Y (en) * 2004-09-20 2005-09-21 赵树林 FET automotive alternator voltage regulator with multiple protective functions
CN101056068A (en) * 2005-09-12 2007-10-17 快捷半导体有限公司 VRMS and rectified current sense full-bridge synchronous-rectification integrated with PFC
CN101672931A (en) * 2009-09-24 2010-03-17 重庆大学 Unipolar trapezoidal pulse current control method and device of inductive load
CN101713969A (en) * 2009-11-19 2010-05-26 杭州电子科技大学 Anti-clamp circuit of electric skylight

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