CN208257383U - A kind of self-locking over-voltage over-current protection circuit - Google Patents
A kind of self-locking over-voltage over-current protection circuit Download PDFInfo
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- CN208257383U CN208257383U CN201820755482.5U CN201820755482U CN208257383U CN 208257383 U CN208257383 U CN 208257383U CN 201820755482 U CN201820755482 U CN 201820755482U CN 208257383 U CN208257383 U CN 208257383U
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Abstract
A kind of self-locking over-voltage over-current protection circuit, including with phase hysteresis voltage comparator, input terminal is respectively with output voltage/electric current signal by protection circuit test point and reference voltageURef is connected, and output end is respectively at bi-directional voltage stabilizing pipeD ZIt is connected with the end S of synchronous rs flip-flop.It is synchronousRSTriggerREnd ground connection, output are connect by the first triode by the subsequent conditioning circuit of protection circuit.When normal by the output of protection circuit test point, the cut-off of the first triode is worked normally by protection circuit；Conversely, when by protection circuit test point output overvoltage or overcurrent when, the first triode ON, protection starting.Simultaneously becauseRSTrigger has holding effect, even if detection signal reduces and is less than the lower threshold value of hysteresis voltage comparator, rest-set flip-flop output is still high level, to realize the self-locking of pulse blocking signal.
Description
Technical field
The utility model relates to a kind of over-voltage over-current protection circuit, especially a kind of self-locking over-voltage over-current protection circuit.
Background technique
For Switching Power Supply, if blocking driving signal in circuit malfunctions, after failure vanishes, open immediately
Driving signal is put, can not necessarily be played a protective role to circuit.Due to blocking driving signal, circuit will stop working, and examine
The signal measured does not reflect failure, and circuit will appear starting and stopping repeatedly, so for the catastrophe failures such as short circuit, at this time
It is necessary to protect circuit using self-locking.
Utility model content
In view of this, the utility model is intended to provide a kind of self-locking over-voltage over-current protection circuit.
To achieve the above object, the utility model uses following technical scheme:
A kind of self-locking over-voltage over-current protection circuit, including with phase hysteresis voltage comparator, output end respectively with it is two-way
The end S of voltage-stabiliser tube and synchronous rs flip-flop is connected, the end R of synchronous rs flip-flop ground connection, its output of synchronous rs flip-flop and the
The base stage of one triode connects.
It includes circuit test point, and circuit test point passes through the non-inverting input terminal of resistance R1 and same phase hysteresis voltage comparator
It is connected.
The reverse input end of the same phase hysteresis voltage comparator is successively connect with resistance R2, Voltage Reference end.
The output end of the same phase hysteresis voltage comparator connects through resistance R3 and bi-directional voltage stabilizing pipe and resistance R5 respectively
It connects, the both ends of resistance R5 are connect with the non-inverting input terminal of same phase hysteresis voltage comparator, output end respectively.
The output end of the same phase hysteresis voltage comparator is successively connected with the end S of resistance R3, synchronous rs flip-flop.
The asynchronous resetting end CLR of the synchronous rs flip-flop is connected to the collector of the second triode, and+12V power supply is through electricity
Resistance R6, R7 and key S is connected in the collector and base stage of the second triode respectively.
Synchronous rs flip-flop output is connected by resistance R4 with the base stage of the first triode.
The collector of first triode connects by the subsequent conditioning circuit of protection circuit.
By adopting the above technical scheme, following technical effect has been obtained: when normal by the output of protection circuit test point, warp
After crossing hysteresis voltage comparator, output is-UZ(low level), the end S of rest-set flip-flop is low level at this time, rest-set flip-flop
Output is also low level, and the cut-off of the first triode is worked normally by the subsequent conditioning circuit of protection circuit.When monitoring for protection point exported
When pressure or overcurrent, after hysteresis voltage comparator, output is+UZ(high level), the end S of rest-set flip-flop is high electricity at this time
Flat, the output of rest-set flip-flop is high level, and the first triode ON protects circuit start.Since rest-set flip-flop has holding effect,
Even if detecting signal to reduce and be less than UT-When, rest-set flip-flop output is still high level, to realize oneself of pulse blocking signal
Lock.
After debugging, if necessary to reset, key S can be made to connect, then the second triode ON, to make asynchronous
Clear terminal CLR is effective, so that rest-set flip-flop be made to reset.
Detailed description of the invention
Fig. 1 is the circuit diagram of the utility model
Fig. 2 is the transmission characteristic of same phase hysteresis voltage comparator
Specific embodiment
The utility model is further elaborated in the following with reference to the drawings and specific embodiments.
A kind of self-locking over-voltage over-current protection circuit, including with phase hysteresis voltage comparator 1, output end respectively with it is two-way
The end S of voltage-stabiliser tube 2 and synchronous rs flip-flop 3 is connected, the end R of synchronous rs flip-flop ground connection, its output of synchronous rs flip-flop 3 with
The base stage of first triode 4 connects.
It includes circuit test point 5, and circuit test point 5 passes through the same phase of resistance R16 and same phase hysteresis voltage comparator 1
Input terminal is connected.
The reverse input end of the same phase hysteresis voltage comparator 1 is successively connect with resistance R27, Voltage Reference end 9.
The output end of the same phase hysteresis voltage comparator 1 connects through resistance R38 and bi-directional voltage stabilizing pipe 2 and resistance R5 respectively
It connects, the both ends of resistance R510 are connect with the non-inverting input terminal of same phase hysteresis voltage comparator 1, output end respectively.
The output end of the same phase hysteresis voltage comparator 1 is successively connected with the end S of resistance R38, synchronous rs flip-flop.
The asynchronous resetting end CLR of the synchronous rs flip-flop 3 is connected to the collector of the second triode 11 ,+12V power supply
It is connected in the collector and base stage of the second triode 11 respectively through resistance R6, R7 and key S.
Wherein, the output of synchronous rs flip-flop 3 is connected by resistance R4 with the base stage of the first triode 4, the first triode 4
Collector connects by the subsequent conditioning circuit 12 of protection circuit.
Specifically, self-locking over-voltage over-current protection circuit, including with phase hysteresis voltage comparator, output voltage/electric current letter
Number be connected by resistance R1 with the non-inverting input terminal of comparator by protection circuit test point, reference voltage UrefThrough resistance R2 with
The reverse input end of comparator is connected, and output end is respectively through resistance R3 and bi-directional voltage stabilizing pipe DZ, by resistance R4 and comparator
Non-inverting input terminal be connected, be connected with the end S of synchronous rs flip-flop.The end R of synchronous rs flip-flop is grounded.Power supply (+12V) warp
Resistance R6, R7 and key S are connected in the collector and base stage of the second triode, the asynchronous resetting end CLR connection of rest-set flip-flop respectively
In the collector of the second triode.Synchronous rs flip-flop output is connected by resistance R8 with the base stage of the first triode, switching tube
Q1Collector connect by the subsequent conditioning circuit of protection circuit, emitter ground connection.
In the present embodiment, rest-set flip-flop is that high level triggering is effective, QnFor the initial state of trigger output, Qn+1For trigger
The next state of output, state characteristic table are as shown in the table.
| CP | R | S | Qn+1 | Explanation |
| 0 | X | X | Qn | It keeps |
| 1 | 0 | 0 | Qn | It keeps |
| 1 | 0 | 1 | 1 | Set 1 |
| 1 | 1 | 0 | 0 | Set 0 |
| 1 | 1 | 1 | It is indefinite | Do not allow |
In the present embodiment, two threshold values with phase hysteresis loop comparator are respectively as follows: The threshold band of comparatorIt, can in order to improve the anti-interference ability of comparator
By adjusting feedback resistance R5 and input resistance R1, and to meet R1< < R5。
If the original state of rest-set flip-flop is 0, gradually increase when by the output voltage/electric current of protection circuit less than hysteresis electricity
Press the upper threshold value U of comparatorT+When, comparator output is-UZ(low level), the end S of rest-set flip-flop is low level at this time, therefore RS is touched
The output of hair device is also low level, and the cut-off of the first triode is worked normally by the subsequent conditioning circuit of protection circuit.
When by the output voltage/electric current of protection circuit gradually increase and be greater than hysteresis voltage comparator upper threshold value UT+When,
Its output voltage is+UZ(high level), the end S of rest-set flip-flop is high level at this time, and the output of rest-set flip-flop is high level, first
Triode ON, transistor collector voltage are pulled low, and the subsequent conditioning circuit of circuit is protected not work, and protect circuit start.By
There is holding effect in rest-set flip-flop, even if reducing and comparing less than hysteresis voltage when by the output voltage/electric current of protection circuit
The lower threshold value U of deviceT-When, rest-set flip-flop output is still high level, to realize the self-locking of pulse blocking signal.
Claims (8)
1. a kind of self-locking over-voltage over-current protection circuit, which is characterized in that including same phase hysteresis voltage comparator (1), output
End is connected with the end S of bi-directional voltage stabilizing pipe (2) and synchronous rs flip-flop (3) respectively, the end the R ground connection of synchronous rs flip-flop, synchronous
Its output of rest-set flip-flop (3) is connect with the base stage of the first triode (4).
2. a kind of self-locking over-voltage over-current protection circuit according to claim 1, which is characterized in that it includes circuit detection
Point (5), circuit test point (5) are connected by resistance R1 (6) with the non-inverting input terminal of same phase hysteresis voltage comparator (1).
3. a kind of self-locking over-voltage over-current protection circuit according to claim 1, which is characterized in that the same phase hysteresis electricity
The reverse input end of pressure comparator (1) is successively connect with resistance R2 (7), Voltage Reference end (9).
4. according to claim 1 to a kind of 3 one of them described self-locking over-voltage over-current protection circuit, which is characterized in that institute
The output end for stating same phase hysteresis voltage comparator (1) is connect through resistance R3 (8) with bi-directional voltage stabilizing pipe (2) and resistance R5 respectively,
The both ends of resistance R5 (10) are connect with the non-inverting input terminal of same phase hysteresis voltage comparator (1), output end respectively.
5. a kind of self-locking over-voltage over-current protection circuit according to claim 4, which is characterized in that the same phase hysteresis electricity
The output end of pressure comparator (1) is successively connected with the end S of resistance R3 (8), synchronous rs flip-flop.
6. a kind of self-locking over-voltage over-current protection circuit according to claim 4, which is characterized in that the synchronous RS triggering
The asynchronous resetting end CLR of device (3) is connected to the collector of the second triode (11), and+12V power supply is through resistance R6, R7 and key S points
It is not connected in the collector and base stage of the second triode (11).
7. a kind of self-locking over-voltage over-current protection circuit according to claim 5 or 6, which is characterized in that synchronous RS triggering
Device (3) output is connected by resistance R4 with the base stage of the first triode (4).
8. a kind of self-locking over-voltage over-current protection circuit according to claim 7, which is characterized in that the first triode (4)
Collector connect by the subsequent conditioning circuit (12) of protection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820755482.5U CN208257383U (en) | 2018-05-21 | 2018-05-21 | A kind of self-locking over-voltage over-current protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820755482.5U CN208257383U (en) | 2018-05-21 | 2018-05-21 | A kind of self-locking over-voltage over-current protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN208257383U true CN208257383U (en) | 2018-12-18 |
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ID=66480931
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820755482.5U Expired - Fee Related CN208257383U (en) | 2018-05-21 | 2018-05-21 | A kind of self-locking over-voltage over-current protection circuit |
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| Country | Link |
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| CN (1) | CN208257383U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109856435A (en) * | 2019-01-11 | 2019-06-07 | 深圳赛意法微电子有限公司 | The high pressure monitoring and protecting device of state latching circuit and the application circuit |
| CN110456141A (en) * | 2019-08-28 | 2019-11-15 | 安徽贵博新能科技有限公司 | A kind of flash over-current detection circuit and its method |
-
2018
- 2018-05-21 CN CN201820755482.5U patent/CN208257383U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109856435A (en) * | 2019-01-11 | 2019-06-07 | 深圳赛意法微电子有限公司 | The high pressure monitoring and protecting device of state latching circuit and the application circuit |
| CN109856435B (en) * | 2019-01-11 | 2021-07-06 | 深圳赛意法微电子有限公司 | State latch circuit and high-voltage monitoring protection device applying same |
| CN110456141A (en) * | 2019-08-28 | 2019-11-15 | 安徽贵博新能科技有限公司 | A kind of flash over-current detection circuit and its method |
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| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| 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: 20181218 Termination date: 20190521 |