CN205453079U - Overcurrent protection circuit of electronic switch - Google Patents
Overcurrent protection circuit of electronic switch Download PDFInfo
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- CN205453079U CN205453079U CN201521114690.XU CN201521114690U CN205453079U CN 205453079 U CN205453079 U CN 205453079U CN 201521114690 U CN201521114690 U CN 201521114690U CN 205453079 U CN205453079 U CN 205453079U
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- comparator
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Abstract
The utility model provides a pair of overcurrent protection circuit of electronic switch, its input are the electrical power unit input, output termination external load, including the control level who is used for providing overcurrent protection circuit of electronic switch working power supply, a close and open the switch tube for controlling the output anode, be used for providing the driven driver for the switch tube, the switch tube is used for playing the first resistance of metering function for control level after switching on, be used for providing offset voltage second resistance for the driver, a reference circuit for providing the datum point overflows, a voltage acquisition circuit for gathering voltage between first end of switch tube and the switch tube second end, a voltage locking circuit for comparing sample voltage and the comparison circuit that overflows the datum point with be used for preventing that the switch tube from relapseing the switch, the utility model has the characteristics of the circuit is simple, and is with low costs, and the reliability is high.
Description
Technical field
This utility model belongs to electronic device field, is specifically related to a kind of overcurrent protection circuit of electronic switch.Being applicable to heavy DC output control switch, UPS battery input controls switch.
Background technology
At present, in the output of big electric current controls, the general circuit using power resistor or the device such as Hall element and amplifier composition, detects output end current size, compares with reference signal, control switching tube as cut-off signals, carry out overcurrent protection.This circuit is because have employed the devices such as power resistor, amplifier or Hall element, and electrical resistance collection loss is relatively big, and Hall element is expensive, makes the production cost of electronic equipment improve, and circuit is relative complex simultaneously, and reliability is low.
Summary of the invention
Disadvantages described above or Improvement requirement for prior art; this utility model provides a kind of overcurrent protection circuit of electronic switch; voltage between switching tube the first end and switching tube the second end is gathered, it is judged that whether switching tube crosses stream by the voltage collection circuit being made up of resistance, electric capacity and diode.
nullThis utility model provides a kind of overcurrent protection circuit of electronic switch，Its input Vin is power-supply device input，Output end vo ut connects external loading，It is characterized in that control level RFOFF included for providing overcurrent protection circuit of electronic switch working power，For controlling the switching tube S1 of output plus terminal Vout+ start or stop，For providing the driver driven for switching tube S1，After turning on as switching tube S1, control level RFOFF is risen the first resistance R1 of metering function，For providing the second resistance R2 of bias voltage for driver，For providing the reference circuit of stream datum mark，For gathering the voltage collection circuit of voltage between switching tube S1 the first end and switching tube S1 the second end、For comparing sampled voltage and crossing the comparison circuit of stream datum mark and for the voltage lock circuit preventing switching tube S1 from repeatedly switching.
Described reference circuit includes manostat N1 and the 4th resistance R4, and first end of manostat N1 is connected with output plus terminal Vout+, and second end of manostat N1 and the 4th resistance R4 the first end are connected, and the 4th resistance R4 the second end and first resistance R1 the second end are connected.
Described voltage collection circuit includes the first diode V1, the 5th resistance R5, the 3rd resistance R3 and the first electric capacity C1, the negative electrode of the first diode V1 is connected with input anode Vin+, first diode V1 anode and the 5th resistance R5 the second end are connected, 5th resistance R5 the first end and the 3rd resistance R3 the second end are connected, 3rd resistance R3 the first end is connected with output plus terminal Vout+, first electric capacity C1 the first end is connected with output plus terminal Vout+, first electric capacity C1 the second end and the 3rd resistance R3 the second end are connected, and the 5th resistance R5 the second end and first resistance R1 the second end are connected.
Described comparison circuit includes comparator N2 and the second electric capacity C2, the inverting input of comparator N2 and the 3rd resistance R3 the second end are connected, the normal phase input end of comparator N2 is connected with manostat N1 the second end, comparator N2 octal is connected with control level RFOFF, second electric capacity C2 the second end is connected with control level RFOFF, second electric capacity C2 the first end is connected with output plus terminal Vout+, and comparator N2 the 4th foot is connected with output plus terminal Vout+.
Described voltage lock circuit includes the second diode V5,6th resistance R6, second diode V5 anode is connected with the normal phase input end of comparator N2, and the negative electrode of the second diode V5 and the 6th resistance R6 the first end are connected, and the 6th resistance R6 the second end is connected with the outfan of comparator N2.
Described driver includes the first audion V2 and the second audion V3, first audion V2 is NPN audion and the second audion V3 is PNP triode, the colelctor electrode of the first audion V2 and second end of the first resistance R1 are connected, the base stage of the first audion V2 is connected with the outfan of comparator N2, the emitter stage of the first audion V2 and the emitter stage of the second audion V3 are connected, the base stage of the second audion V3 is connected with the outfan of comparator N2, and the colelctor electrode of the second audion V3 is connected with output plus terminal Vout+.Driver is for providing driving for switching tube S1.
First end of described first resistance R1 is connected with control level RFOFF, second resistance R2 the first end is connected with control level RFOFF, second resistance R2 the second end and the first audion V2 base stage are connected, first resistance R1 plays metering function after turning on as switching tube S1, and the second resistance R2 is for providing bias voltage for the first audion V2；The second termination output plus terminal Vout+ of first termination input the anode Vin+, switching tube S1 of switching tube S1, the emitter stage of switching tube S1 the 3rd end and the first audion V2 is connected.
Described 4th resistance R4 and manostat N1 can replace by a reference source, and described first audion V2 and the second audion V3 can replace by integrated driver.
A kind of overcurrent protection circuit of electronic switch that this utility model provides goes for heavy DC output control switch, and it is that switching tube provides protection, this kind of circuit to have circuit simply that UPS battery inputs control switch, low cost, the feature that reliability is high.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of a kind of overcurrent protection circuit of electronic switch that this utility model provides.
Detailed description of the invention
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, this utility model is further elaborated.Should be appreciated that specific embodiment described herein, only in order to explain this utility model, is not used to limit this utility model.As long as just can be mutually combined additionally, technical characteristic involved in each embodiment of this utility model disclosed below does not constitutes conflict each other.
nullAs shown in Figure 1，A kind of overcurrent protection circuit of electronic switch that this utility model provides，Its input Vin is power-supply device input，Output end vo ut connects external loading，Including control level RFOFF for providing overcurrent protection circuit of electronic switch working power，For controlling the start or stop switching tube S1 of output plus terminal Vout+，For providing the driver driven for switching tube S1，After turning on as switching tube S1, control level RFOFF is risen the first resistance R1 of metering function，For providing the second resistance R2 of bias voltage for driver，For providing the reference circuit of stream datum mark，For gathering the voltage collection circuit of voltage between switching tube S1 the first end and switching tube S1 the second end，For comparing sampled voltage and crossing the comparison circuit of stream datum mark and for the voltage lock circuit preventing switching tube S1 from repeatedly switching.
Reference circuit includes manostat N1 and the 4th resistance R4, and the anode of manostat N1 is connected with output plus terminal Vout+, and the negative electrode of manostat N1 and the 4th resistance R4 the first end are connected, and the 4th resistance R4 the second end and first resistance R1 the second end are connected.Manostat N1 and the 4th resistance R4 is used for providing stream datum mark.
Voltage collection circuit includes the first diode V1, the 5th resistance R5, the 3rd resistance R3 and the first electric capacity C1, the negative electrode of the first diode V1 is connected with input anode Vin+, first diode V1 anode and the 5th resistance R5 the second end are connected, 5th resistance R5 the first end and the 3rd resistance R3 the second end are connected, 3rd resistance R3 the first end is connected with output plus terminal Vout+, first electric capacity C1 the first end is connected with output plus terminal Vout+, first electric capacity C1 the second end and the 3rd resistance R3 the second end are connected, and the 5th resistance R5 the second end and first resistance R1 the second end are connected.First diode V1 is used for isolating input high pressure.5th resistance R5, the 3rd resistance R3 composition bleeder circuit is used for gathering switching tube S1 both end voltage, and the first electric capacity C1 prevents misoperation for filtering interfering.
Comparison circuit includes comparator N2, the second electric capacity C2, the inverting input of comparator N2 and the 3rd resistance R3 the second end are connected, the normal phase input end of comparator N2 is connected with manostat N1 the second end, comparator N2 octal is connected with control level RFOFF, second electric capacity C2 the second end is connected with control level RFOFF, second electric capacity C2 the first end is connected with output plus terminal Vout+, comparator N2 the 4th foot is connected with output plus terminal Vout+, and sampled voltage is used for the power filter for comparator N2 with the comparison of flow point benchmark excessively, the second electric capacity C2 for comparing by comparator N2.
Voltage lock circuit includes the second diode V5,6th resistance R6, second diode V5 anode is connected with the normal phase input end of comparator N2, the negative electrode of the second diode V5 and the 6th resistance R6 the first end are connected, 6th resistance R6 the second end is connected with the outfan of comparator N2, and voltage lock circuit switchs repeatedly for circuit is locked from switching tube S1.
Driver includes the first audion V2 and the second audion V3, first audion V2 is NPN audion and the second audion V3 is PNP triode, the colelctor electrode of the first audion V2 and second end of the first resistance R1 are connected, the base stage of the first audion V2 is connected with the outfan of comparator N2, the emitter stage of the first audion V2 and the emitter stage of the second audion V3 are connected, the base stage of the second audion V3 is connected with the outfan of comparator N2, and the colelctor electrode of the second audion V3 is connected with output plus terminal Vout+.Driver is for providing driving for switching tube S1.
First end of the first resistance R1 is connected with control level RFOFF.Second resistance R2 the first end is connected with control level RFOFF, and second resistance R2 the second end and the first audion V2 base stage are connected.First resistance R1 plays metering function after turning on as switching tube S1, and the second resistance R2 is for providing bias voltage for the first audion V2；Control level RFOFF is for providing the working power of circuit.
The second termination output plus terminal Vout+ of first termination input the anode Vin+, switching tube S1 of switching tube S1, the emitter stage of switching tube S1 the 3rd end and the first audion V2 is connected, and switching tube S1 is for controlling to export the start or stop of Vout.
Wherein the 4th resistance R4 and manostat N1 can replace by other a reference source.First audion V2 and the second audion V3 can replace by integrated driver.Manostat N1 can use TL431, the anode that the first end is TL431 of manostat, the negative electrode that the second end is TL431 of manostat.
Operation principle is as follows: during normal work, RF0FF send high level (+12V), the 3 foot voltages of comparator N2 are set up voltage time by the 4th resistance R4 and manostat N1 and are set up fast than the 5th resistance R5, the first electric capacity C1 on 2 feet of comparator N2 and the 3rd resistance R3,1 foot of comparator N2 sets high, the open collector of the second audion V3.Control level RFOFF signal delivers to the first audion V2, the first audion V2 conducting, now switching tube S1 conducting through the first resistance R1, the second resistance R2.First diode V1 conducting after switching tube S1 conducting.Assuming that the first diode V1 is ideal diode, the 2 foot voltages of comparator N2 are (Vin-Vout) × R3 (R3+R5), if R3 (R3+R5) is k, the 2 foot voltages of comparator N2 are reduced to (Vin-Vout) × k.If the voltage of switching tube S1 the first end and switching tube S1 the second end reduces to Vs, then having, the 2 foot voltages of comparator N2 are VS × k.
If there is big electric current, then switching tube S1 both end voltage can rise, and the 2 foot voltages of comparator N2 are VS × k, rise the most therewith.When the 2 foot voltages of comparator N2 are increased beyond the threshold value of 3 feet settings of comparator N2, comparator N2 overturns the second audion V3 conducting and is closed by switching tube S1, simultaneously by the second diode V5, comparator N2 is remained rollover states by the lock circuit of the 6th resistance R6 composition, switching tube S1 remains closedown, thus prevents switching tube S1 from repeatedly switching and cause switching tube S1 to damage.
During normal switching-off, RF0FF send low level (0V), and all circuit lose power supply and reset.
After having served as flowing Failure elimination, RF0FF send high level (+12V) again, and circuit restarts work.
Those skilled in the art is easy to understand; the foregoing is only preferred embodiment of the present utility model; not in order to limit this utility model; all any amendment, equivalent and improvement etc. made within spirit of the present utility model and principle, within should be included in protection domain of the present utility model.
Claims (9)
1. an overcurrent protection circuit of electronic switch, its input is power-supply device input, output termination external loading, it is characterized in that the control level included for providing overcurrent protection circuit of electronic switch working power, for controlling the switching tube of output plus terminal start or stop, for providing the driver driven for switching tube, after turning on when switching tube, control level is risen the first resistance of metering function, for providing the second resistance of bias voltage for driver, for providing the reference circuit of stream datum mark, for gathering the voltage collection circuit of voltage between switching tube the first end and switching tube the second end, for comparing sampled voltage and crossing the comparison circuit of stream datum mark and for the voltage lock circuit preventing switching tube from repeatedly switching.
2. a kind of overcurrent protection circuit of electronic switch as claimed in claim 1; it is characterized in that described reference circuit includes manostat and the 4th resistance; first end of manostat is connected with output plus terminal; second end of manostat and the 4th resistance the first end are connected, and the 4th resistance the second end and first resistance the second end are connected.
3. a kind of overcurrent protection circuit of electronic switch as claimed in claim 1, it is characterized in that described voltage collection circuit includes the first diode, 5th resistance, 3rd resistance and the first electric capacity, the negative electrode of the first diode is connected with input anode, first diode anode and the 5th resistance the second end are connected, 5th resistance the first end and the 3rd resistance the second end are connected, 3rd resistance the first end is connected with output plus terminal, first electric capacity the first end is connected with output plus terminal, first electric capacity the second end and the 3rd resistance the second end are connected, 5th resistance the second end and first resistance the second end are connected.
4. a kind of overcurrent protection circuit of electronic switch as claimed in claim 1; it is characterized in that described comparison circuit includes comparator and the second electric capacity; the inverting input of comparator and the 3rd resistance the second end are connected; the normal phase input end of comparator is connected with manostat the second end; comparator octal is connected with control level; second electric capacity the second end is connected with control level, and second electric capacity the first end is connected with output plus terminal, and comparator the 4th foot is connected with output plus terminal.
5. a kind of overcurrent protection circuit of electronic switch as claimed in claim 1; it is characterized in that described voltage lock circuit includes the second diode; 6th resistance; second diode anode is connected with the normal phase input end of comparator; the negative electrode of the second diode and the 6th resistance the first end are connected, and the 6th resistance the second end is connected with the outfan of comparator.
6. a kind of overcurrent protection circuit of electronic switch as claimed in claim 1; it is characterized in that described driver includes the first audion and the second audion; first audion is NPN audion and the second audion is PNP triode; the colelctor electrode of the first audion and the second end of the first resistance are connected; the base stage of the first audion is connected with the outfan of comparator; the emitter stage of the first audion and the emitter stage of the second audion are connected; the base stage of the second audion is connected with the outfan of comparator, and the colelctor electrode of the second audion is connected with output plus terminal.
7. a kind of overcurrent protection circuit of electronic switch as claimed in claim 1; it is characterized in that the first end of described first resistance is connected with control level; second resistance the first end is connected with control level; second resistance the second end and the first transistor base are connected; first resistance plays metering function after turning on when switching tube, and the second resistance is for providing bias voltage for the first audion；First termination input anode of switching tube, the second termination output plus terminal of switching tube, the emitter stage of switching tube the 3rd end and the first audion is connected.
8. a kind of overcurrent protection circuit of electronic switch as claimed in claim 2, it is characterised in that described 4th resistance and manostat can replace by a reference source.
9. a kind of overcurrent protection circuit of electronic switch as claimed in claim 6, it is characterised in that described first audion and the second audion can replace by integrated driver.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521114690.XU CN205453079U (en) | 2015-12-30 | 2015-12-30 | Overcurrent protection circuit of electronic switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521114690.XU CN205453079U (en) | 2015-12-30 | 2015-12-30 | Overcurrent protection circuit of electronic switch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205453079U true CN205453079U (en) | 2016-08-10 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201521114690.XU Expired - Fee Related CN205453079U (en) | 2015-12-30 | 2015-12-30 | Overcurrent protection circuit of electronic switch |
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| Country | Link |
|---|---|
| CN (1) | CN205453079U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115377937A (en) * | 2022-10-24 | 2022-11-22 | 浙江富特科技股份有限公司 | Electronic fuse structure, power supply device comprising same and working method of power supply device |
-
2015
- 2015-12-30 CN CN201521114690.XU patent/CN205453079U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115377937A (en) * | 2022-10-24 | 2022-11-22 | 浙江富特科技股份有限公司 | Electronic fuse structure, power supply device comprising same and working method of power supply device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20160810 |