CN208955639U - A kind of input over under-voltage protection circuit - Google Patents
A kind of input over under-voltage protection circuit Download PDFInfo
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- CN208955639U CN208955639U CN201821442922.8U CN201821442922U CN208955639U CN 208955639 U CN208955639 U CN 208955639U CN 201821442922 U CN201821442922 U CN 201821442922U CN 208955639 U CN208955639 U CN 208955639U
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Abstract
The utility model discloses a kind of input over under-voltage protection circuits, including first resistor R1, second resistance R2,3rd resistor R3, the 4th resistance R4, capacitor C1, zener diode ZD1, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the 9th resistance R9, the tenth resistance R10, the first triode Q1 and the second triode Q2；The base stage of first triode Q1 is separately connected the other end, one end of the 9th resistance R9 and one end of the tenth resistance R10 of the 4th resistance R4, the collector of first triode Q1 is separately connected base stage, one end of the 5th resistance R5 and one end of the 6th resistance R6 of the second triode Q2, the other end of 5th resistance R5 is separately connected the other end and power supply VCC of the tenth resistance R10, and the other end of the 6th resistance R6 is separately connected one end of the emitter of the first triode Q1, the emitter of the second triode Q2 and the 8th resistance R8.The utility model circuit is simple, is quick on the draw.
Description
Technical field
The utility model relates to driving power technical fields, and in particular to a kind of input over under-voltage protection circuit is applied
In LED illumination driving.
Background technique
Existing over-voltage, under-voltage protecting circuit and overcurrent protection circuit generally use operational amplifier to constitute comparator,
Its working principle is that: when input voltage is lower than setting overvoltage/undervoltage value, output is closed, output electric current is minimum setting value；When defeated
When entering voltage and being increased to setting recovery value, exports and automatic restore normal.
The setting of existing over-voltage, under-voltage protecting circuit and overcurrent protection circuit is generally complex, required electronics member
The quantity of part is more, and manufacturing cost is higher, at the same it is existing in over-voltage, under-voltage protecting circuit and overcurrent circuit there is also
React the problems such as insensitive, protection is unreliable.
Utility model content
In view of this, the utility model proposes a kind of input overvoltage/undervoltage guarantors in order to solve the above problem in the prior art
Protection circuit.
The utility model is solved the above problems by following technological means:
A kind of input over under-voltage protection circuit, including first resistor R1, second resistance R2,3rd resistor R3, the 4th resistance
R4, capacitor C1 and zener diode ZD1；One end of first resistor R1 connects input voltage Vbus, the other end of first resistor R1
It is separately connected the cathode of zener diode ZD1 and one end of second resistance R2, the anode of zener diode ZD1 is separately connected third
One end of resistance R3, one end of capacitor C1 and the 4th resistance R4 one end, the other end of 3rd resistor R3 be separately connected second electricity
Hinder the other end of R2 and the other end of capacitor C1, the other end ground connection of capacitor C1；
It further include the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the 9th resistance R9, the tenth resistance
R10, the first triode Q1 and the second triode Q2；The base stage of first triode Q1 be separately connected the 4th resistance R4 the other end,
One end of 9th resistance R9 and one end of the tenth resistance R10, the collector of the first triode Q1 are separately connected the second triode Q2
Base stage, one end of the 5th resistance R5 and one end of the 6th resistance R6, the other end of the 5th resistance R5 is separately connected the tenth resistance
The other end and power supply VCC, the other end of the 6th resistance R6 of R10 is separately connected the emitter of the first triode Q1, the two or three pole
One end of the emitter of pipe Q2 and the 8th resistance R8, the other end of the 8th resistance R8 are separately connected the current collection of the second triode Q2
Pole, the other end of the 9th resistance R9 and the 7th resistance R7 one end, the 7th resistance R7 the other end connection IC foot DIM.
Further, the first triode Q1 and the second triode Q2 is NPN type.
Compared with prior art, the beneficial effects of the utility model include at least:
1), circuit is simple, and electronic component is few, and manufacturing cost is low, practical.
2) it, is quick on the draw, securely and reliably.
3) it, can solve the problem of lamp during under-voltage restart does not flash.
Detailed description of the invention
It, below will be to required in embodiment description in order to illustrate more clearly of the technical scheme in the embodiment of the utility model
Attached drawing to be used is briefly described, it should be apparent that, the accompanying drawings in the following description is only some realities of the utility model
Example is applied, it for those of ordinary skill in the art, without creative efforts, can also be according to these attached drawings
Obtain other attached drawings.
Fig. 1 is the circuit diagram of the utility model input over under-voltage protection circuit.
Specific embodiment
To keep the above objects, features, and advantages of the utility model more obvious and easy to understand, below in conjunction with attached drawing and
The technical solution of the utility model is described in detail in specific embodiment.It should be pointed out that described embodiment is only
It is only the utility model a part of the embodiment, instead of all the embodiments, based on the embodiments of the present invention, this field
Those of ordinary skill's every other embodiment obtained without making creative work, belongs to the utility model
The range of protection.
As shown in Figure 1, the utility model provides a kind of input over under-voltage protection circuit, including first resistor R1, the second electricity
Hinder R2,3rd resistor R3, the 4th resistance R4, capacitor C1 and zener diode ZD1；One end of first resistor R1 connects input voltage
Vbus, the other end of first resistor R1 are separately connected the cathode of zener diode ZD1 and one end of second resistance R2, two pole of pressure stabilizing
The anode of pipe ZD1 is separately connected one end of one end of 3rd resistor R3, one end of capacitor C1 and the 4th resistance R4,3rd resistor R3
The other end be separately connected the other end of second resistance R2 and the other end of capacitor C1, the other end ground connection of capacitor C1；
It further include the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the 9th resistance R9, the tenth resistance
R10, the first triode Q1 and the second triode Q2；The base stage of first triode Q1 be separately connected the 4th resistance R4 the other end,
One end of 9th resistance R9 and one end of the tenth resistance R10, the collector of the first triode Q1 are separately connected the second triode Q2
Base stage, one end of the 5th resistance R5 and one end of the 6th resistance R6, the other end of the 5th resistance R5 is separately connected the tenth resistance
The other end and power supply VCC, the other end of the 6th resistance R6 of R10 is separately connected the emitter of the first triode Q1, the two or three pole
One end of the emitter of pipe Q2 and the 8th resistance R8, the other end of the 8th resistance R8 are separately connected the current collection of the second triode Q2
Pole, the other end of the 9th resistance R9 and the 7th resistance R7 one end, the 7th resistance R7 the other end connection IC foot DIM.
Specifically, the first triode Q1 and the second triode Q2 is NPN type.
The input over under-voltage protection circuit working principle of the utility model is as follows:
1, initial power-on: situation is connected in the first triode Q1 and the second triode Q2, may be due to the difference of supply voltage
And result is different, is divided by first resistor R1 and second resistance R2, if initial voltage is greater than 12.7V, the first triode Q1
Conducting, the second triode Q2 shutdown, exports always at this time as high level, if initial voltage is less than 8.6V, (parameter in figure) by
Vbus × (R3+R4)/(R3+R4+R7+R9)=0.7V is calculated, then the first triode Q1 is turned off, and the second triode Q2 is led
It is logical, it exports as low level.So in overvoltage crowbar, so that it may upper voltage limit is set by 12.7V, in under-voltage protection electricity
Lu Zhong, so that it may set lower voltage limit for 8.6V, be determined by using, low level be exported to the DIM of IC at this time, to control electricity
Source output electric current is the minimum value of setting.
2, it (wants one to be less than 8.6V under normal operating conditions or is greater than 12.7V), analyze under-voltage circuit conditions: circuit is big
It is worked normally in 12.7V, if in the case of certain, appearance is under-voltage, and the second triode Q2 is still off, at this time due to 3rd resistor
The circuit of R3, the 4th resistance R4, the 9th resistance R9, the 7th resistance R7 composition, so that Qa1 is constantly on, when VDD < 8.6V,
(Vbe < 0.7V) is connected insufficient for Qa1, the second triode Q2 is connected at this time, exports low level.That is, under-voltage protection
Low voltage value be 8.6V.After voltage recovery, since the second triode Q2 is constantly on, so the 9th right voltage of resistance R9 is always
Almost 0, when VDD is greater than 12.7V, the voltage of 0.7V is generated by voltage-stabiliser tube, so that the first triode Q1 is connected again,
Second triode Q2 shutdown, exports as height.
3, therefore, under under-voltage application, the voltage protection range that may be implemented is<8.6V, and opening range is>12.7V, together
Sample, it is achieved that normal work < 8.6V is opened, is greater than 12.7V and ends in overvoltage protection, and it is lower opposite that logical AND is under-voltage.
Tenth resistance R10 does not flash for lamp during under-voltage restart.
4, pass through the resistance value of the 9th resistance R9 of adjusting, thus it is possible to vary the lower limit value of protection passes through and adjusts voltage-stabiliser tube, Ke Yigai
Become the upper limit value of protection.
5, upper limit value are as follows: Vd1+0.7V.
6, lower limit value is 0.7 × (R3+R4+R9+R7)/(R3+R4)=V.
7, in this circuit, retarding window are as follows: 8.6V-12.7V.
8, to the use of foregoing circuit, the control signal of metal-oxide-semiconductor can be will be output as, can also be turned by optocoupler level
It changes, is input to MCU and carries out voltage detecting judgement.
Compared with prior art, the beneficial effects of the utility model include at least:
1), circuit is simple, and electronic component is few, and manufacturing cost is low, practical.
2) it, is quick on the draw, securely and reliably.
3) it, can solve the problem of lamp during under-voltage restart does not flash.
Above-described embodiments merely represent several embodiments of the utility model, the description thereof is more specific and detailed,
But it should not be understood as limiting the scope of the patent of the utility model.It should be pointed out that for the common of this field
For technical staff, without departing from the concept of the premise utility, various modifications and improvements can be made, these all belong to
In the protection scope of the utility model.Therefore, the scope of protection shall be subject to the appended claims for the utility model patent.
Claims (2)
1. a kind of input over under-voltage protection circuit, which is characterized in that including first resistor R1, second resistance R2,3rd resistor R3,
4th resistance R4, capacitor C1 and zener diode ZD1；One end of first resistor R1 connects input voltage Vbus, first resistor R1
The other end be separately connected the cathode of zener diode ZD1 and one end of second resistance R2, the anode of zener diode ZD1 is respectively
One end, one end of capacitor C1 and one end of the 4th resistance R4 of 3rd resistor R3 are connected, the other end of 3rd resistor R3 connects respectively
Connect the other end of second resistance R2 and the other end of capacitor C1, the other end ground connection of capacitor C1；
Further include the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the 9th resistance R9, the tenth resistance R10,
First triode Q1 and the second triode Q2；The base stage of first triode Q1 is separately connected the other end of the 4th resistance R4, the 9th
One end of one end of resistance R9 and the tenth resistance R10, the collector of the first triode Q1 are separately connected the base of the second triode Q2
Pole, one end of the 5th resistance R5 and the 6th resistance R6 one end, the other end of the 5th resistance R5 is separately connected the tenth resistance R10's
The other end and power supply VCC, the other end of the 6th resistance R6 are separately connected the emitter of the first triode Q1, the second triode Q2
One end of emitter and the 8th resistance R8, the other end of the 8th resistance R8 are separately connected the collector of the second triode Q2, the 9th
One end of the other end of resistance R9 and the 7th resistance R7, the foot DIM of the other end connection IC of the 7th resistance R7.
2. input over under-voltage protection circuit according to claim 1, which is characterized in that the first triode Q1 and the two or three pole
Pipe Q2 is NPN type.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821442922.8U CN208955639U (en) | 2018-09-04 | 2018-09-04 | A kind of input over under-voltage protection circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821442922.8U CN208955639U (en) | 2018-09-04 | 2018-09-04 | A kind of input over under-voltage protection circuit |
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| Publication Number | Publication Date |
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| CN208955639U true CN208955639U (en) | 2019-06-07 |
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| CN201821442922.8U Active CN208955639U (en) | 2018-09-04 | 2018-09-04 | A kind of input over under-voltage protection circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112542818A (en) * | 2019-09-23 | 2021-03-23 | 中车株洲电力机车研究所有限公司 | Input undervoltage protection circuit and power panel comprising same |
-
2018
- 2018-09-04 CN CN201821442922.8U patent/CN208955639U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112542818A (en) * | 2019-09-23 | 2021-03-23 | 中车株洲电力机车研究所有限公司 | Input undervoltage protection circuit and power panel comprising same |
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