CN103872890B - Switch power circuit with short circuit protective function - Google Patents

Switch power circuit with short circuit protective function Download PDF

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Publication number
CN103872890B
CN103872890B CN201410127345.3A CN201410127345A CN103872890B CN 103872890 B CN103872890 B CN 103872890B CN 201410127345 A CN201410127345 A CN 201410127345A CN 103872890 B CN103872890 B CN 103872890B
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circuit
resistance
short
switching power
constant
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CN103872890A (en
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陈建根
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Guangzhou Shiyuan Electronics Thecnology Co Ltd
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Guangzhou Shiyuan Electronics Thecnology Co Ltd
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Abstract

The invention discloses a switch power circuit with a short circuit protective function. The switch power circuit with the short circuit protective function comprises a main power switching circuit, a constant-current and constant-voltage control circuit and a short circuit protective circuit. Through the connection of control signals, the main power switching circuit controls an electric energy converting process of a resonance controller chip, power conversion is carried out on voltage signals at a power input end, and output voltage signals are reduced. The constant-current and constant-voltage control circuit is provided with a current loop and a voltage loop, and is used for monitoring voltage signals at the output voltage end of a switch power source in real time and controlling the switch power circuit to work in a constant-current and constant-voltage pattern when short circuit happens to the switch power circuit. When the short circuit happens to the switch power source and the fact that the switch power circuit enters the constant-current and constant-voltage pattern is detected, the short circuit protective circuit transmits overvoltage protective signals, controls the working state of the resonance controller chip and reduces the output voltage signals. The switch power circuit has the advantages of being low in power consumption, resistant to temperature rising, strong in load capacity and wide in application range.

Description

A kind of switching power circuit with short-circuit protection function
Technical field
A kind of the present invention relates to electronic technology field, more particularly to switching power circuit with short-circuit protection function.
Background technology
At present, Switching Power Supply has become the main flow power supply on market, with the maturing of Switching Power Supply, standardization with it is international Change, the requirement to Switching Power Supply is more harsh in the world.And as the world is to the energy and the pay attention to day by day of environmental issue, switch electricity The development in source with apply in energy saving, economize on resources and the aspect such as environmental protection is also imperative, for this purpose, famous both at home and abroad Switching Power Supply manufacturer the problems such as energy-conservation, efficiency, power consumption, environmental protection on especially pay attention to, while volume, weight to Switching Power Supply, Quality, safety, use environment, Centralized Monitoring, parallel-operation expansion etc. propose more requirements.
Currently, traditional Switching Power Supply does not consider to work as load equipment(External devices or external equipment)It is short-circuited The power consumption and problem of temperature rise of Shi Zaocheng switching power circuits.In order to solve the problem in prior art, switching power circuit is entered Row is improved, and for example, adopts self-locking manner to output short-circuit, i.e., once detection finds short circuit phenomenon, then close output voltage, so Resulted in Switching Power Supply need to reset again start could normal work, while also reducing the load capacity of Switching Power Supply;This Outward, also another kind of Switching Power Supply on output short-circuit using beat every(Self- recoverage)Mode tackling the generation of short-circuit conditions. Although the technical scheme can serve the effect of short-circuit protection to a certain extent, which is without constant current constant voltage mode of operation control The Switching Power Supply of system thus be difficult to the application of parallel-operation expansion and limit switch power supply.And pure constant current constant voltage type switch electricity Have the disadvantage during the output short-circuit of source, Switching Power Supply(About 1000 watts)The general loss for having tens watts, so as to cause the waste of the energy, And will also result in the temperature rise of power supply and exceed the requirement of safety standard, there is serious potential safety hazard, while can not expire Podomere energy, environmental requirement.
The content of the invention
The technical problem to be solved is to provide a kind of switching power circuit with short-circuit protection function, energy It is enough to be reduced or switched off output voltage signal, protection switch power circuit energy saving consumption when being short-circuited, and realize electricity The parallel function in source.
For solving above technical problem, the present invention provides a kind of switching power circuit with short-circuit protection function, including:
Main power conversion circuit, by incoming control signal, controls to the electric energy transfer process of resonant controller chip System, carries out power conversion to the voltage signal of power input, reduces output voltage signal, with the protection switch when being short-circuited Power circuit;
Constant-current and constant-voltage control circuit, is provided with current loop and voltage loop, the output voltage of real-time monitoring Switching Power Supply The voltage signal at end, and control the switching power circuit when switching power circuit is short-circuited and be operated in constant current constant voltage mould Formula;
And, short-circuit protection circuit, being short-circuited and detect the switching power circuit in Switching Power Supply enters constant current During constant voltage mode, overvoltage protection signal is sent to the main power conversion circuit, control the work of the resonant controller chip State, reduces output voltage signal.
In a kind of achievable mode, the short-circuit protection circuit includes the first operational amplifier, overvoltage protection signal end With Switching Power Supply secondary feeder ear, and, by the first diode, the second diode, first resistor, second resistance, 3rd resistor, 4th resistance, the 5th resistance, the 6th resistance, the first electric capacity, the second electric capacity, the 3rd electric capacity, the 4th electric capacity and protection optocoupler transmitting The peripheral circuit of device composition;
Wherein, the protection optocoupler transmitter is sequentially connected in series with the first resistor, the first diode, and the protection light The minus earth of coupling transmitter, anode are connected with the either end of the first resistor;First diode is common cathode double two Pole pipe, an and anode of first diode is connected with the overvoltage protection signal end, first diode it is another Individual anode is connected with the anode of second diode;
One end ground connection of first electric capacity, the other end are connected with the anode of second diode;Two or two pole It is connected on the normal phase input end of first operational amplifier after the negative electrode series connection second resistance of pipe;First computing The positive power source terminal of amplifier is the Switching Power Supply secondary feeder ear;The negative power end ground connection of first operational amplifier;Institute One end ground connection of the second electric capacity is stated, the other end is connected to the Switching Power Supply secondary feeder ear;One termination of the 3rd electric capacity Ground, the other end are connected to the normal phase input end of first operational amplifier;
One end of the 3rd resistor is connected to the inverting input of first operational amplifier, electricity on the basis of the other end Pressure side;One end of 4th resistance is connected with the inverting input of first operational amplifier, other end ground connection;First fortune The output end for calculating amplifier is connected with the anode of the second diode;
One end ground connection of the 5th resistance, the other end are connected with the normal phase input end of first operational amplifier;Institute The one end for stating the 6th resistance is connected with the normal phase input end of first operational amplifier, and the other end is Current amplifier sampling end; One end ground connection of the 4th electric capacity, the other end are connected on the inverting input of first operational amplifier.
Preferably, resistance of the short-circuit protection circuit by the regulation second resistance, controlling switch power circuit are entered Enter self-locking state or self- recoverage state.
Further, the short-circuit protection circuit also includes the second operational amplifier, output voltage test side, mode of operation Control end, and, by the 7th resistance, the 8th resistance, the 9th resistance, the tenth resistance, the 11st resistance, the 12nd resistance, the tenth The peripheral circuit of three resistance, the 3rd diode, the 5th electric capacity and first crystal triode composition;
Wherein, one end of the 7th resistance is connected with the Current amplifier sampling end, and the other end is connected to described second In the output end of operational amplifier;5th resistance, the 6th resistance, the 7th resistance are constituted with the 3rd electric capacity Delay circuit;
The negative electrode of the 3rd diode is connected in the output end of second operational amplifier, anode and the described 8th One end connection of resistance;
It is connected on the reference voltage terminal after 8th resistance and the 9th resistant series;Second computing is put The normal phase input end of big device is connected on the series connection point of the 8th resistance and the 9th resistance;One end connection of the tenth resistance In the inverting input of second operational amplifier, the other end is the output voltage test side;
The emitter stage of the first crystal triode is connected with the Current amplifier sampling end, grounded collector, and base stage connects It is connected on the series connection point of the 11st resistance and the 12nd resistance;A termination after 11st resistance and the 12nd resistant series Ground, the other end are the mode of operation control end;One end ground connection after 13rd resistance is in parallel with the 5th electric capacity, the other end It is connected with the normal phase input end of second operational amplifier.
A kind of switching power circuit with short-circuit protection function that the present invention is provided, has the advantages that:Pass through Main power conversion circuit is set, the electric energy transfer process of resonant controller chip therein is controlled by incoming control signal System, carries out power conversion to the voltage signal of power input, reduces output voltage signal, with the protection switch when being short-circuited Power circuit;Constant current constant voltage pattern is operated in by arranging the constant-current and constant-voltage control circuit control switching power circuit, is improved The load capacity of switching power circuit;By arranging short-circuit protection circuit to drive main power conversion circuit when being short-circuited, Reduce output voltage signal, protection switch power circuit simultaneously realizes the parallel function of switching power circuit.Therefore, the present invention is provided Switching power circuit on the basis of short-circuit protection is realized, while solving power consumption that output short-circuit brings and temperature rise is asked Topic, the load capacity for enhancing switching power circuit and the scope of application for having widened switching power circuit.
Description of the drawings
Fig. 1 is the structural representation of the first embodiment of the switching power circuit with short-circuit protection function that the present invention is provided Figure.
Fig. 2 is a kind of physical circuit schematic diagram of the short-circuit protection circuit that first embodiment of the invention is provided.
Fig. 3 is another physical circuit schematic diagram that the present invention provides the short-circuit protection circuit that second embodiment is provided.
Fig. 4 is a kind of circuit theory diagrams of the constant-current and constant-voltage control circuit that second embodiment of the invention is provided.
Fig. 5 is a kind of complete circuit schematic diagram of the switching power circuit that second embodiment of the invention is provided.
Fig. 6 is the partial circuit schematic diagram of the main power conversion circuit that second embodiment of the invention is provided.
Specific embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation is described.
Referring to Fig. 1, it is the knot of the first embodiment of the switching power circuit with short-circuit protection function that the present invention is provided Structure schematic diagram.
Specifically, the described switching power circuit with short-circuit protection function, including:
Main power conversion circuit 100, by incoming control signal, is carried out to the electric energy transfer process of resonant controller chip Control, carries out power conversion to the voltage signal of power input, reduces output voltage signal, opened with protecting when being short-circuited Powered-down source circuit;
Constant-current and constant-voltage control circuit 200, is provided with current loop and voltage loop, the output electricity of real-time monitoring Switching Power Supply The voltage signal of pressure side, and control the switching power circuit when switching power circuit is short-circuited and be operated in constant current constant voltage mould Formula;
And, short-circuit protection circuit 300, being short-circuited and detect the switching power circuit in Switching Power Supply enters permanent During stream constant voltage mode, overvoltage protection signal is sent to the main power conversion circuit 100, control the resonant controller chip Working condition, reduces output voltage signal.
In the present embodiment, described short-circuit protection circuit 300 can be realized using various implementations.
Referring to Fig. 2, it is a kind of physical circuit schematic diagram of the short-circuit protection circuit that first embodiment of the invention is provided.
In a kind of achievable mode, the short-circuit protection circuit 300 includes the first operational amplifier U1, overvoltage protection letter Number end OVP and Switching Power Supply secondary feeder ear VDD, and, by the first diode D1, the second diode D2, first resistor R1, the Two resistance R2,3rd resistor R3, the 4th resistance R4, the 5th resistance R5, the 6th resistance R6, the first electric capacity C1, the second electric capacity C2, The peripheral circuit of three electric capacity C3, the 4th electric capacity C4 and protection optocoupler transmitter PC2A compositions.
Wherein, the protection optocoupler transmitter PC2A is sequentially connected in series with first resistor R1, the first diode D1, and institute State the minus earth of protection optocoupler transmitter PC2A, anode to be connected with the either end of first resistor R1;One or two pole Pipe D1 is common-cathode dual-diode, and an anode of the first diode D1 is connected with the overvoltage protection signal end OVP, Another anode of the first diode D1 is connected with the anode of the second diode D2.
One end ground connection of the first electric capacity C1, the other end are connected with the anode of the second diode D2;Described second It is connected on the in-phase input end of the first operational amplifier U1 after negative electrode series connection second resistance R2 of diode D2;Institute The positive power source terminal for stating the first operational amplifier U1 is the Switching Power Supply secondary feeder ear VDD;The first operational amplifier U1 Negative power end ground connection;One end ground connection of the second electric capacity C2, the other end are connected to the Switching Power Supply secondary feeder ear VDD;One end ground connection of the 3rd electric capacity C3, the other end are connected to the normal phase input end of the first operational amplifier U1.
One end of 3rd resistor R3 is connected to the inverting input of the first operational amplifier U1, and the other end is base Quasi- voltage end REF;One end of 4th resistance R4 is connected with the inverting input of the first operational amplifier U1, another termination Ground;The output end of the first operational amplifier U1 is connected with the anode of the second diode D2;When being embodied as, it is preferable that institute State voltage on the basis of the voltage signal of reference voltage terminal REF access 5V.
One end ground connection of the 5th resistance R5, the other end are connected with the normal phase input end of the first operational amplifier U1 Connect;One end of the 6th resistance R6 is connected with the normal phase input end of the first operational amplifier U1, and the other end is put for electric current Big sampling end IS;One end ground connection of the 4th electric capacity C4, the other end are connected to the anti-phase defeated of the first operational amplifier U1 Enter on end.
Further, when being embodied as, resistance of the short-circuit protection circuit 300 by regulation second resistance R2, Controlling switch power circuit enters self-locking state or self- recoverage state.When the resistance of second resistance R2 is larger, short-circuit protection electricity Road 300 launches into lock-out state when short circuit is detected;When the resistance of second resistance R2 is less, short-circuit protection circuit 300 Self- recoverage mode of operation, i.e. intermittent start is entered when being short-circuited(Hiccup)To obtain self-healing purpose.
In second embodiment of the invention, the basic composition of switching power circuit and circuit theory with first embodiment phase Together.The present embodiment with the difference of first embodiment is:On the basis of first embodiment, short-circuit protection circuit is done further Improvement, with the power consumption that solves to bring during switching power circuit output short-circuit and problem of temperature rise, and improve switching power circuit Load capacity, and realize the simultaneously machine design of multiple switch power supply.
Referring to Fig. 3, it is another the physical circuit principle for the short-circuit protection circuit that the present invention provides second embodiment offer Figure.
As shown in figure 3, on the basis of first embodiment, further, the short-circuit protection circuit 300 also includes second Operational amplifier U2, output voltage test side V-CT, mode of operation control end MODE, and, by the 7th resistance R7, the 8th resistance R8, the 9th resistance R9, the tenth resistance R10, the 11st resistance R11, the 12nd resistance R12, the 13rd resistance R13, the three or two pole The peripheral circuit of pipe D3, the 5th electric capacity C5 and first crystal triode Q1 compositions.
Wherein, one end of the 7th resistance R7 is connected with the Current amplifier sampling end IS, and the other end is connected to described In the output end of the second operational amplifier U2;The 5th resistance R5, the 6th resistance R6, the 7th resistance R7 with it is described 3rd electric capacity C3 constitutes delay circuit.
The negative electrode of the 3rd diode D3 is connected in the output end of the second operational amplifier U2, anode with it is described One end connection of the 8th resistance R8.
The 8th resistance R8 is connected on the reference voltage terminal REF after being connected with the 9th resistance R9;Described The normal phase input end of two operational amplifier U2 is connected on the series connection point of the 8th resistance R8 and the 9th resistance R9;Described tenth One end of resistance R10 is connected to the inverting input of the second operational amplifier U2, and the other end is detected for the output voltage End V-CT.
The emitter stage of the first crystal triode Q1 is connected with the Current amplifier sampling end IS, grounded collector, base Pole is connected on the series connection point of the 11st resistance R11 and the 12nd resistance R12;The 11st resistance R11 and the 12nd resistance One end ground connection after R12 series connection, the other end is mode of operation control end MODE;The 13rd resistance R13 is electric with the 5th One end ground connection after appearance C5 is in parallel, the other end are connected with the normal phase input end of the second operational amplifier U2.
When being embodied as, when switching power circuit is short-circuited, mode of operation control end MODE exports high level, Control the first crystal triode Q1 and enter cut-off state, so as to controlling switch power circuit enters constant current mode.
Further, the constant-current and constant-voltage control circuit that the present embodiment is provided also includes current amplification circuit, and described Current amplification circuit is sequentially connected with the current loop, the voltage loop.Preferably, the constant-current and constant-voltage control circuit is also Including the overvoltage crowbar being connected with the voltage loop.
Referring to Fig. 4, it is a kind of circuit theory diagrams of the constant-current and constant-voltage control circuit that second embodiment of the invention is provided.
When being embodied as, constant-current and constant-voltage control circuit is provided with resistance R14~R40, diode D4~D9, electric capacity C6~C22, Operational amplifier U3~U6, and the feedback optocoupler transmitter PC1A of current loop and voltage loop and former limit.Constant current constant voltage control Circuit processed combines peripheral circuit, also plays a part of a kind of short-circuit protection, and over-pressed signal protection end OVP is connected with short-circuit protection circuit Connecing, by controlling the resistance value of second resistance R2, controlling self-locking pattern to be operated in when its resistance value is larger, resistance value is compared with hourly worker Make in self- recoverage pattern.
Referring to Fig. 5, it is a kind of complete circuit schematic diagram of the switching power circuit that second embodiment of the invention is provided.
The basic functional principle of the switching power circuit provided by the present embodiment is:When switching power circuit output occur it is short Lu Shi, current sample end-IS locate the gathered amplified circuit of current sampling signal, current loop and enter constant current mode, then work Operation mode control end MODE exports high level, causes first crystal triode Q1 to enter cut-off state;Now, when output voltage is examined Survey the detected output voltages for obtaining of end V-CT and be less than the reference voltage accessed by the positive input of the second operational amplifier U2 When, cause the output signal of the second operational amplifier U2 to overturn, i.e., the output end of the second operational amplifier U2 is high level signal, Jing after the delay circuit constituted by the 5th resistance R5, the 6th resistance R6, the 7th resistance R7 and the 3rd electric capacity C3 enters line delay, letter Number being sent to the first operation amplifier comparator U1 is compared;Signal Jing after relatively is defeated from the first operational amplifier U1 output ends Go out, then feed back to the control of former limit after the first diode D1, first resistor R1 and protection optocoupler transmitter PC2A are processed Chip, i.e., in described resonant controller chip, so as to controlling switch power circuit cuts out output voltage signal, protection switch power supply Circuit.
When being embodied as, according to above circuit operation principle, when switching power circuit enters guard mode, it is necessary to meet with Lower three conditions:First, switching power circuit enters constant current mode, i.e. first crystal triode Q1 cut-offs;Second, output voltage The voltage signal detected by test side V-CT is less than reference voltage(Reference voltage value can be designed as needed, it is preferable that adopt With voltage on the basis of the voltage signal of 5V);3rd, switching power circuit enters the time of constant current mode, more than delay circuit Time delay.
Referring to Fig. 6, it is the partial circuit schematic diagram of the main power conversion circuit that second embodiment of the invention is provided.
Specifically, the main power conversion circuit 100 includes:Sent for accessing the protection optocoupler transmitter PC2A Control signal, and control the protection optocoupler receiver that the resonant controller chip U7 closes output voltage when being short-circuited PC2B.Therefore, the control signal for being sent from protection optocoupler transmitter PC2A can be by set by main power conversion circuit 100 Protection optocoupler receiver pc 2B is received, so as to reach the purpose of the output voltage values of controlling switch power circuit, according to opening Whether powered-down source circuit is short-circuited and controls whether to close electric power output voltage.When being embodied as, the resonant controller core Piece U7 is provided with postpones signal end DELAY, and is connected with the protection optocoupler receiver by the postpones signal end, accesses by institute State the control signal sent by short-circuit protection circuit.
Therefore, the switching power circuit provided by second embodiment of the invention by circuit parameter, including current sample Signal, output voltage, RC time constants progressively compare process, control resonant controller chip by protecting optocoupler transmitter Postpones signal end DELAY input signal, so as to reach controlling switch power circuit when short circuit is detected enter self-locking mode Formula or self- recoverage pattern, and reach the purpose of short-circuit protection.
This kind of circuit design can solve the power supply power consumption caused by short circuit and temperature rise in the purpose for reaching short-circuit protection Problem, and overcome traditional switch power circuit realize a kind of short-circuit protection of pattern, load capacity difference and narrow application range Defect.And as switching power circuit remains constant current constant voltage function, therefore can easily realize N+1 parallel-operation expansions; And neatly different loads is powered according to the demand of client, therefore reduce to PCB(Printed circuit board (PCB))Change plate Number of times;As circuit design is more flexible, taking up room for design cost and pcb board is reduced, therefore greatly strengthen switch The practicality of power circuit.
It should be noted that Fig. 6 only depicts the delay with protection optocoupler receiver pc 2B and resonant controller chip U7 Signal end DELAY(Pin 2)Connection and relative electronic components, and feedback light coupling receiver PC1B and its and resonant controller The catenation principle figure of chip U7.When being embodied as, resonant controller chip U7 is necessarily also provided with peripheral circuit by other pins, With the output voltage of controlling switch power circuit.Preferably, the resonant controller chip U7 can adopt model L6599ADTR Chip realized.
Preferably, switching power circuit provided in an embodiment of the present invention can be applicable to PWM(Pulse Width Modulation, pulsewidth modulation)In control chip.
The above is the preferred embodiment of the present invention, it is noted that for those skilled in the art For, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications are also considered as Protection scope of the present invention.

Claims (9)

1. a kind of switching power circuit with short-circuit protection function, it is characterised in that include:
Main power conversion circuit, by incoming control signal, is controlled to the electric energy transfer process of resonant controller chip, right The voltage signal of power input carries out power conversion, reduces output voltage signal, with the protection switch power supply when being short-circuited Circuit;
Constant-current and constant-voltage control circuit, is provided with current loop and voltage loop, the output voltage terminal of real-time monitoring Switching Power Supply Voltage signal, and control the switching power circuit when switching power circuit is short-circuited and be operated in constant current constant voltage pattern;
And, short-circuit protection circuit, being short-circuited and detect the switching power circuit in Switching Power Supply enters constant current constant voltage During pattern, overvoltage protection signal is sent to the main power conversion circuit, controls the working condition of the resonant controller chip, Reduce output voltage signal;
The short-circuit protection circuit includes the first operational amplifier, overvoltage protection signal end and Switching Power Supply secondary feeder ear, with And, by the first diode, the second diode, first resistor, second resistance, 3rd resistor, the 4th resistance, the 5th resistance, the 6th The peripheral circuit of resistance, the first electric capacity, the second electric capacity, the 3rd electric capacity, the 4th electric capacity and protection optocoupler transmitter composition;
Wherein, the protection optocoupler transmitter is sequentially connected in series with the first resistor, the first diode, and the protection optocoupler is sent out The minus earth of emitter, anode are connected with the either end of the first resistor;First diode is common-cathode dual-diode, And an anode of first diode is connected with the overvoltage protection signal end, another anode of first diode It is connected with the anode of second diode;
One end ground connection of first electric capacity, the other end are connected with the anode of second diode;Second diode It is connected on the normal phase input end of first operational amplifier after the negative electrode series connection second resistance;First operation amplifier The positive power source terminal of device is the Switching Power Supply secondary feeder ear;The negative power end ground connection of first operational amplifier;Described One end ground connection of two electric capacity, the other end are connected to the Switching Power Supply secondary feeder ear;One end ground connection of the 3rd electric capacity, separately One end is connected to the normal phase input end of first operational amplifier;
One end of the 3rd resistor is connected to the inverting input of first operational amplifier, voltage on the basis of the other end End;One end of 4th resistance is connected with the inverting input of first operational amplifier, other end ground connection;First computing The output end of amplifier is connected with the anode of the second diode;
One end ground connection of the 5th resistance, the other end are connected with the normal phase input end of first operational amplifier;Described One end of six resistance is connected with the normal phase input end of first operational amplifier, and the other end is Current amplifier sampling end;It is described One end ground connection of the 4th electric capacity, the other end are connected on the inverting input of first operational amplifier.
2. the switching power circuit of short-circuit protection function is carried as claimed in claim 1, it is characterised in that the short-circuit protection Resistance of the circuit by the regulation second resistance, controlling switch power circuit enter self-locking state or self- recoverage state.
3. the switching power circuit of short-circuit protection function is carried as claimed in claim 1, it is characterised in that the short-circuit protection Circuit also includes the second operational amplifier, output voltage test side, mode of operation control end, and, by the 7th resistance, the 8th electric Resistance, the 9th resistance, the tenth resistance, the 11st resistance, the 12nd resistance, the 13rd resistance, the 3rd diode, the 5th electric capacity and The peripheral circuit of one transistor composition;
Wherein, one end of the 7th resistance is connected with the Current amplifier sampling end, and the other end is connected to second computing In the output end of amplifier;5th resistance, the 6th resistance, the 7th resistance constitute time delay with the 3rd electric capacity Circuit;
The negative electrode of the 3rd diode is connected in the output end of second operational amplifier, anode and the 8th resistance One end connection;
It is connected on the reference voltage terminal after 8th resistance and the 9th resistant series;Second operational amplifier Normal phase input end be connected on the series connection point of the 8th resistance and the 9th resistance;One end of tenth resistance is connected to institute The inverting input of the second operational amplifier is stated, the other end is the output voltage test side;
The emitter stage of the first crystal triode is connected with the Current amplifier sampling end, and grounded collector, base stage are connected to On the series connection point of the 11st resistance and the 12nd resistance;One end ground connection after 11st resistance and the 12nd resistant series, The other end is the mode of operation control end;After 13rd resistance is in parallel with the 5th electric capacity one end ground connection, the other end with The normal phase input end connection of second operational amplifier.
4. the switching power circuit of short-circuit protection function is carried as claimed in claim 3, it is characterised in that the main power becomes Changing circuit includes:For accessing the control signal sent by the protection optocoupler transmitter, and control when being short-circuited described Resonant controller chip closes the protection optocoupler receiver of output voltage.
5. the switching power circuit with short-circuit protection function as described in claim 3 or 4, it is characterised in that when switch electricity When source circuit is short-circuited, the mode of operation control end exports high level, controls the first crystal triode and enters cut-off State, so as to controlling switch power circuit enters constant current mode.
6. the switching power circuit of short-circuit protection function is carried as claimed in claim 5, it is characterised in that the resonance control Device chip is provided with postpones signal end, and is connected with the protection optocoupler receiver by the postpones signal end, accesses by described The control signal sent by short-circuit protection circuit.
7. the switching power circuit of short-circuit protection function is carried as claimed in claim 6, it is characterised in that the constant current constant voltage Control circuit also includes current amplification circuit, and the current amplification circuit is with the current loop, the voltage loop successively Connection.
8. the switching power circuit of short-circuit protection function is carried as claimed in claim 7, it is characterised in that the constant current constant voltage Control circuit also includes the overvoltage crowbar being connected with the voltage loop.
9. the switching power circuit of short-circuit protection function is carried as claimed in claim 8, it is characterised in that the resonance control Chip of the device chip for model L6599ADTR.
CN201410127345.3A 2014-03-31 2014-03-31 Switch power circuit with short circuit protective function Active CN103872890B (en)

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FR3083397B1 (en) * 2018-06-28 2020-08-21 Valeo Equip Electr Moteur SWITCH AND SWITCH ARM CONTROL SYSTEM
CN112994430B (en) * 2021-02-26 2022-03-22 西安微电子技术研究所 Multi-mode combined short-circuit protection circuit and working method and application thereof
CN117460122B (en) * 2023-12-21 2024-04-30 厦门普为光电科技有限公司 Lighting device with fault detection and self-locking control functions

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CN1564421A (en) * 2004-03-17 2005-01-12 毛锦铭 Charger for lithium cell
CN201821141U (en) * 2010-10-18 2011-05-04 李彬斌 Charger device with direct current voltage reduction and conversion function
CN202210884U (en) * 2011-08-26 2012-05-02 上海新华电子设备有限公司 Multi-path constant current driving power supply for LED illumination
CN202424283U (en) * 2012-02-09 2012-09-05 广州市君盘实业有限公司 Charger based on single-chip three-end TOP22X integrated chip
CN202586463U (en) * 2012-04-16 2012-12-05 无锡市威德盛电子有限公司 Nickel-cadmium charger control circuit
CN103442501A (en) * 2013-09-12 2013-12-11 江华 Forced constant flow source dimming LED (Light Emitting Diode) lamp

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1564421A (en) * 2004-03-17 2005-01-12 毛锦铭 Charger for lithium cell
CN201821141U (en) * 2010-10-18 2011-05-04 李彬斌 Charger device with direct current voltage reduction and conversion function
CN202210884U (en) * 2011-08-26 2012-05-02 上海新华电子设备有限公司 Multi-path constant current driving power supply for LED illumination
CN202424283U (en) * 2012-02-09 2012-09-05 广州市君盘实业有限公司 Charger based on single-chip three-end TOP22X integrated chip
CN202586463U (en) * 2012-04-16 2012-12-05 无锡市威德盛电子有限公司 Nickel-cadmium charger control circuit
CN103442501A (en) * 2013-09-12 2013-12-11 江华 Forced constant flow source dimming LED (Light Emitting Diode) lamp

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