CN204290268U - A kind of protective circuit - Google Patents
A kind of protective circuit Download PDFInfo
- Publication number
- CN204290268U CN204290268U CN201420701874.5U CN201420701874U CN204290268U CN 204290268 U CN204290268 U CN 204290268U CN 201420701874 U CN201420701874 U CN 201420701874U CN 204290268 U CN204290268 U CN 204290268U
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- voltage
- switching tube
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- power supply
- triode
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Abstract
The utility model relates to protective device technical field, particularly relates to a kind of embedded device protective circuit.Comprise power supply, in order to provide voltage, protection module, is connected between described Voltage stabilizing module and load, and is the positive pole of overvoltage and/or power output end in described electric power, under negative pole connects anti-state, controls described load and described power supply disconnects.Compared with prior art, the utility model has the advantages that: protection module carries out " preliminary examination " the voltage that power supply exports in advance, judges whether voltage is normal voltage, meet, then Voltage stabilizing module conducting if detect, do not meet if detect, then Voltage stabilizing module turns off.Effectively prevent improper voltage and connect load.Improve the fail safe of load running.
Description
Technical field
The utility model relates to protective device technical field, particularly relates to a kind of embedded device protective circuit.
Background technology
Along with improving constantly of people's living standard, the life of embedded device and people is closely bound up, and it is related to the stable sustainable development of national economy, therefore requires higher to its stability and reliability.And in actual applications, often occur because misoperation or some uncertain factors cause embedded device to burn out goods short circuit, the positive opposite ends connection error of such as power supply, or the output voltage of power supply is excessively high, all can damage embedded device, under harsh conditions, serious economic loss can be caused.
Utility model content
For the deficiencies in the prior art, the utility model provides the protective circuit being applied to embedded device, and concrete technical scheme is as follows:
A kind of protective circuit, is applied to embedded device, wherein, comprises
Power supply, in order to provide voltage;
Protection module, is connected between described power supply and load, under the voltage exported in described power supply is the positive pole of overvoltage and/or power output end, negative pole connects anti-state, controls described load and described power supply disconnects.
Preferably, described protection module comprises a testing circuit and an overvoltage crowbar;
Testing circuit comprises the first resistance and the first voltage-stabiliser tube, and described overvoltage crowbar comprises the first triode, the first switching tube, the second resistance,
One end of described first resistance connects the positive pole of described power supply, and the other end of described first resistance connects the backward end of described first voltage-stabiliser tube;
The forward end of described first voltage-stabiliser tube connects publicly, and the backward end of described first voltage-stabiliser tube forms the output of described testing circuit,
The base stage of described first triode connects the end of oppisite phase of described first voltage-stabiliser tube, and described in the collector electrode of described first triode is connected by described second resistance publicly, the emitter of described first triode connects the described positive pole of described power supply;
The input of described first switching tube connects the emitter of described first triode, and the control end of described first switching tube connects the collector electrode of described first triode, and the output of described first switching tube connects described load.
Preferably, described protection module comprises reverse connection prevention protection circuit, and described reverse connection prevention protection circuit is formed by second switch pipe;
The input of described second switch pipe connects the output of described first switching tube; The output of described second switch pipe connects described load; Described in the control end connection of described second switch pipe publicly.
Preferably, described first triode is PNP triode.
Preferably, described first switching tube is the first PMOS, and the input of described first switching tube is the source electrode of a described PMOS; The output of described first switching tube is the drain electrode of described first PMOS, and the control end of described first switching tube is the grid of described first PMOS.
Preferably, described second switch pipe is the second PMOS, and the input of described second switch pipe is the drain electrode of described 2nd PMOS; The output of described second switch pipe is the source electrode of described second PMOS, and the control end of described second switch pipe is the grid of described second PMOS.
Preferably, the Standard resistance range of described second resistance is 4.7k Ω ~ 10k Ω.
Preferably, also comprise the first electric capacity, described first electric capacity is connected between the input of described first switching tube and the control end of described first switching tube.
Preferably, described first operating state is described power supply is described load supplying; Described second operating state is form open circuit between described power supply and described load.
Compared with prior art; the utility model has the advantages that: protection module carries out " preliminary examination " the voltage that power supply exports in advance; judge whether voltage is normal voltage; meet if detect; then protection module conducting, power supply is load supplying, does not meet if detect; then protection module turns off, and power supply and load disconnect.Effectively prevent improper voltage and connect load.Improve the fail safe of load running.
Accompanying drawing explanation
Fig. 1 is square frame connection layout of the present utility model;
Fig. 2 is circuit connection diagram of the present utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail, but not as restriction of the present utility model.
As shown in Figure 1, a kind of protective circuit, is applied to embedded device, wherein, comprises
Power supply, in order to provide electric power; The voltage of 5V or 12V can be provided.
Protection module, is connected between described power supply and a load, is the positive pole of overvoltage and/or power output end in described electric power, under negative pole connects anti-state, controls described load and described power supply disconnects.
In the utility model, protection module carries out " preliminary examination " the voltage that power supply exports in advance, judges whether the voltage that power supply exports is normal voltage, meets, then protection module conducting if detect, and does not meet if detect, then protection module turns off.Effectively prevent improper voltage and connect load.Improve the fail safe of load running.
As further preferred embodiment, as shown in Figure 2, described protection module comprises overvoltage crowbar and testing circuit;
Described testing circuit comprises the first resistance R1 and the first voltage-stabiliser tube D1, and one end of described first resistance R1 connects the positive pole of described power supply, and the other end of described first resistance R1 connects the backward end of described first voltage-stabiliser tube D1; The forward end of described first voltage-stabiliser tube D1 connects publicly, and the backward end of described first voltage-stabiliser tube D1 forms the output of institute's testing circuit.The output voltage of testing circuit is adjustable-voltage.For providing voltage for the base stage of the first triode Q1.
Described overvoltage crowbar comprises the first triode Q1, the first switching tube K1, the second resistance R2, and the first triode Q1 adopts PNP triode.
The base stage of described first triode Q1 connects the backward end of described first voltage-stabiliser tube D1, and described in the collector electrode of described first triode Q1 is connected by described second resistance R2 publicly, the emitter of described first triode Q1 connects the described positive pole of described power supply; The Standard resistance range of described second resistance R2 is 4.7k Ω ~ 10k Ω.
The input of described first switching tube K1 connects the emitter of described first triode Q1, control end connects the collector electrode of described first triode Q1, output connects described load, and described first electric capacity C1 is connected between the input of described first switch and the control end of described first switching tube K1.
When the voltage that power supply exports is normal value, the emitter junction conducting of the first triode Q1, collector junction ends, first triode Q1 is in cut-off state, the then current collection very low level of the first triode Q1, the control end of the first switching tube K1 is low level, the first switching tube K1 conducting, and power supply is to load normal power supply; When electric power output voltage is outlier, the emitter junction conducting of the first triode Q1, collector junction conducting, the then current collection very high level of the first triode Q1, the control end of the first switching tube K1 is high level, and the first switching tube K1 disconnects, and the improper voltage that power supply exports cannot export load to.Thus achieve over-voltage protection function.Wherein the second resistance R2 is pull down resistor, in order to when normal power supply, makes the control end of the first switching tube K1 be in low level state.
As further preferred embodiment, as shown in Figure 2, described protection module comprises reverse-connection preventing circuit, and described reverse connection prevention protection circuit is formed by second switch pipe K2;
The input of described second switch pipe K2 connects the output of described first switching tube K1;
The output of described second switch pipe K2 connects described load, described in the control end connection of described second switch pipe K2 publicly.
When the situation of reversal connection (both positive and negative polarity of power supply connects instead) has appearred in power output end, the control end of second switch pipe K2 has been in and has connect high level, and second switch pipe K2 is in the state of shutoff, and power supply cannot be powered.Anti-reverse function is achieved by second switch pipe K2.
As further preferred embodiment, described first switching tube K1 is the first PMOS, and the input of described first switching tube K1 is the source electrode of a described PMOS; The output of described first switching tube K1 is the drain electrode of described first PMOS, and the control end of described first switching tube K1 is the grid of described first PMOS.
As further preferred embodiment, described second switch pipe K2 is that the second PMOS is formed, and the input of described second switch pipe K2 is the drain electrode of described 2nd PMOS; The output of described second switch pipe K2 is the source electrode of described second PMOS, and the control end of described second switch pipe K2 is the grid of described second PMOS.
As further preferred embodiment, also comprise the first electric capacity C1, the capacitance of the first electric capacity C1 is 0.1UF.Described first electric capacity C1 is connected between the input of described first switching tube K1 and the control end of described first switching tube K1.In order to slow down the ON time of the first switching tube K1, make described first switching tube K1 export a steady voltage, prevent due to voltage spikes and ringing.
The foregoing is only the utility model preferred embodiment; not thereby execution mode of the present utility model and protection range is limited; to those skilled in the art; should recognize and all should be included in the scheme that equivalent replacement done by all utilization the utility model specifications and diagramatic content and apparent change obtain in protection range of the present utility model.
Claims (8)
1. a protective circuit, is applied to embedded device, it is characterized in that, comprises
Power supply, in order to provide voltage;
Protection module, is connected between described power supply and a load, under the voltage exported in described power supply is the positive pole of overvoltage and/or power output end, negative pole connects anti-state, controls described load and described power supply disconnects.
2. protective circuit according to claim 1, is characterized in that, described protection module comprises a testing circuit and an overvoltage crowbar;
Testing circuit comprises the first resistance and the first voltage-stabiliser tube, and described overvoltage crowbar comprises the first triode, the first switching tube, the second resistance,
One end of described first resistance connects the positive pole of described power supply, and the other end of described first resistance connects the backward end of described first voltage-stabiliser tube;
The forward end of described first voltage-stabiliser tube connects publicly, and the backward end of described first voltage-stabiliser tube forms the output of described testing circuit,
The base stage of described first triode connects the end of oppisite phase of described first voltage-stabiliser tube, and described in the collector electrode of described first triode is connected by described second resistance publicly, the emitter of described first triode connects the described positive pole of described power supply;
The input of described first switching tube connects the emitter of described first triode, and the control end of described first switching tube connects the collector electrode of described first triode, and the output of described first switching tube connects described load.
3. protective circuit according to claim 2, is characterized in that, described protection module comprises reverse connection prevention protection circuit, and described reverse connection prevention protection circuit is formed by second switch pipe;
The input of described second switch pipe connects the output of described first switching tube; The output of described second switch pipe connects described load; Described in the control end connection of described second switch pipe publicly.
4. protective circuit according to claim 2, is characterized in that, described first triode is PNP triode.
5. protective circuit according to claim 2, is characterized in that, described first switching tube is the first PMOS, and the input of described first switching tube is the source electrode of a described PMOS; The output of described first switching tube is the drain electrode of described first PMOS, and the control end of described first switching tube is the grid of described first PMOS.
6. protective circuit according to claim 3, is characterized in that, described second switch pipe is the second PMOS, and the input of described second switch pipe is the drain electrode of described 2nd PMOS; The output of described second switch pipe is the source electrode of described second PMOS, and the control end of described second switch pipe is the grid of described second PMOS.
7. protective circuit according to claim 2, is characterized in that, the Standard resistance range of described second resistance is 4.7k Ω ~ 10k Ω.
8. protective circuit according to claim 2, is characterized in that, also comprises the first electric capacity, and described first electric capacity is connected between the input of described first switching tube and the control end of described first switching tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420701874.5U CN204290268U (en) | 2014-11-20 | 2014-11-20 | A kind of protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420701874.5U CN204290268U (en) | 2014-11-20 | 2014-11-20 | A kind of protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204290268U true CN204290268U (en) | 2015-04-22 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420701874.5U Expired - Fee Related CN204290268U (en) | 2014-11-20 | 2014-11-20 | A kind of protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204290268U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106229962A (en) * | 2016-08-11 | 2016-12-14 | 上海能埔电子有限公司 | A kind of power source reverse connection protection circuit |
| CN107749611A (en) * | 2017-11-16 | 2018-03-02 | 盈帜科技（常州）有限公司 | A kind of overvoltage crowbar |
| CN110474291A (en) * | 2019-09-20 | 2019-11-19 | 国网天津市电力公司 | A kind of distribution automation equipment power supply overvoltage protection device |
| CN111313364A (en) * | 2019-11-29 | 2020-06-19 | 南通同洲电子有限责任公司 | Overvoltage protection device and overvoltage protection method |
| CN112098739A (en) * | 2020-05-27 | 2020-12-18 | 深圳天邦达科技有限公司 | Battery package short-circuit protection test circuit, circuit board and test equipment |
-
2014
- 2014-11-20 CN CN201420701874.5U patent/CN204290268U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106229962A (en) * | 2016-08-11 | 2016-12-14 | 上海能埔电子有限公司 | A kind of power source reverse connection protection circuit |
| CN106229962B (en) * | 2016-08-11 | 2018-10-30 | 上海能埔电子有限公司 | A kind of power source reverse connection protection circuit |
| CN107749611A (en) * | 2017-11-16 | 2018-03-02 | 盈帜科技（常州）有限公司 | A kind of overvoltage crowbar |
| CN110474291A (en) * | 2019-09-20 | 2019-11-19 | 国网天津市电力公司 | A kind of distribution automation equipment power supply overvoltage protection device |
| CN111313364A (en) * | 2019-11-29 | 2020-06-19 | 南通同洲电子有限责任公司 | Overvoltage protection device and overvoltage protection method |
| CN112098739A (en) * | 2020-05-27 | 2020-12-18 | 深圳天邦达科技有限公司 | Battery package short-circuit protection test circuit, circuit board and test equipment |
| CN112098739B (en) * | 2020-05-27 | 2024-02-23 | 深圳天邦达科技有限公司 | Battery pack short-circuit protection test circuit, circuit board and test equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150422 Termination date: 20181120 |