CN208753976U - A kind of under-voltage protecting circuit with lag function - Google Patents
A kind of under-voltage protecting circuit with lag function Download PDFInfo
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- CN208753976U CN208753976U CN201821568375.8U CN201821568375U CN208753976U CN 208753976 U CN208753976 U CN 208753976U CN 201821568375 U CN201821568375 U CN 201821568375U CN 208753976 U CN208753976 U CN 208753976U
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Abstract
The utility model discloses a kind of under-voltage protecting circuits with lag function; including capacitor C; one end of the capacitor C is grounded; the other end of capacitor C is connected with one end of one end of controllable silicon SCR, voltage-stabiliser tube Z3; the other end of controllable silicon SCR is connected with applied signal voltage Vin; one end of resistance R1 is connected on applied signal voltage Vin, the other end of resistance R1 is connected with one end of resistance R3 and the anode of hysteresis comparator L, and the other end of voltage-stabiliser tube Z3 is connected with reference voltage Vref.The utility model structure is simple; it is easy to operate; under cooperation by controllable silicon SCR and hysteresis comparator L; so that switching circuit not only can protect circuit; equipment is avoided to be damaged; and the frequent of Switching Power Supply is switched on or off when can fluctuate near under-voltage protection setting voltage to avoid the input voltage of Switching Power Supply, ensure that the overall performance of Switching Power Supply.
Description
Technical field
The utility model relates to under-voltage protecting circuit technical field more particularly to a kind of under-voltage protections with lag function
Circuit.
Background technique
The Input voltage terminal of general Switching Power Supply can all be provided with under-voltage protecting circuit, when preventing input voltage too low,
Load is damaged, still, the under-voltage protecting circuit of the Input voltage terminal of Switching Power Supply does not have sluggishness in the prior art
Function, when the input voltage of Switching Power Supply fluctuates near under-voltage protection setting voltage, end when will result in switching tube,
When and be connected, cause Switching Power Supply to be followed by continually and be switched on or off, will damage switching tube over time, or even influence to open
The overall performance in powered-down source solves above-mentioned ask with this thus it is proposed that a kind of under-voltage protecting circuit with lag function
Topic.
Utility model content
Purpose of the utility model is to solve disadvantages existing in the prior art, and the one kind proposed has sluggish function
The under-voltage protecting circuit of energy.
To achieve the goals above, the utility model adopts the technical scheme that
A kind of under-voltage protecting circuit with lag function, including one end ground connection of capacitor C, the capacitor C, capacitor C's
The other end is connected with one end of one end of controllable silicon SCR, voltage-stabiliser tube Z3, and the other end of controllable silicon SCR is connected with input signal
One end of resistance R1 is connected on voltage Vin, applied signal voltage Vin, the other end of resistance R1 is connected with one end of resistance R3
With the anode of hysteresis comparator L, the other end of voltage-stabiliser tube Z3 is connected with reference voltage Vref, is connected with electricity on reference voltage Vref
One end of R2 is hindered, the other end of resistance R2 is connected to the cathode of hysteresis comparator L, and the first foot ground connection of hysteresis comparator L is sluggish
The crus secunda of comparator L is equipped with one end of positive feedback resistor Rf, and the other end of positive feedback resistor Rf is connected to one end of R3.
Preferably, the model LM339 of the hysteresis comparator L.
Preferably, the resistance value of the resistance R1, resistance R2 and resistance R3 are respectively 5.1k Ω, 10k Ω, 5.1k Ω.
Preferably, the model of the resistance R1, resistance R2 and resistance R3 are RT7X.
Preferably, the capacitance of the capacitor C is 68pF, the model CBB61 of capacitor C.
Preferably, the model 1N4106 of the voltage-stabiliser tube Z3.
Preferably, the model MCA12m of the controllable silicon SCR.
Compared with prior art, the utility model has the beneficial effects that
(1), it is increased when Uo1 is exported, voltage-stabiliser tube Z3 breakdown conducting, the control terminal of controllable silicon SCR obtains trigger voltage, therefore
Controllable silicon SCR conducting, Uo2 voltage shorted to earth, current foldback circuit or short-circuit protection circuit will work, and stop entire power supply
The work of circuit, when the exclusion of output overvoltage phenomenon, silicon-controlled recovery off-state；
(2), when output end be low level when, due to hysteresis comparator L one end electric current very little and only nA grade, so general
It is ignored, and electric current flows to output end from the end reference voltage Vref at this time, and when output end is high level, electric current is from output end at this time
The end reference voltage Vref is flowed to, due to the effect of positive-feedback circuit Rf, there are two threshold voltage, i.e., high values by hysteresis comparator L
Voltage and low threshold voltage, in hysteresis comparator L, as long as voltage causes the amplitude of variation of applied signal voltage to be no more than lag
Voltage, it is ensured that the stabilization of output state；
The utility model structure is simple, easy to operate, under the cooperation by controllable silicon SCR and hysteresis comparator L, so that opening
Powered-down road not only can protect circuit, and equipment is avoided to be damaged, and can to avoid Switching Power Supply input voltage in under-voltage guarantor
The frequent of Switching Power Supply is switched on or off when shield setting voltage nearby fluctuates, and ensure that the overall performance of Switching Power Supply.
Detailed description of the invention
Fig. 1 be the utility model proposes a kind of under-voltage protecting circuit with lag function circuit diagram.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.
Referring to Fig.1, a kind of under-voltage protecting circuit with lag function, including capacitor C, one end ground connection of capacitor C, capacitor
The other end of C is connected with one end of one end of controllable silicon SCR, voltage-stabiliser tube Z3, and the other end of controllable silicon SCR is connected with input letter
One end of resistance R1 is connected on number voltage Vin, applied signal voltage Vin, the other end of resistance R1 is connected with the one of resistance R3
The anode at end and hysteresis comparator L, the other end of voltage-stabiliser tube Z3 are connected with reference voltage Vref, are connected on reference voltage Vref
One end of resistance R2, the other end of resistance R2 are connected to the cathode of hysteresis comparator L, and the first foot of hysteresis comparator L is grounded, late
The crus secunda of stagnant comparator L is equipped with one end of positive feedback resistor Rf, and the other end of positive feedback resistor Rf is connected to one end of R3,
It is increased when Uo1 is exported, voltage-stabiliser tube Z3 breakdown conducting, the control terminal of controllable silicon SCR obtains trigger voltage, therefore controllable silicon SCR is led
Logical, Uo2 voltage shorted to earth, current foldback circuit or short-circuit protection circuit will work, and stop the work of entire power circuit,
When the exclusion of output overvoltage phenomenon, silicon-controlled recovery off-state；When output end is low level, due to the one of hysteresis comparator L
Electric current very little and only nA grades are held, so being ignored, electric current flows to output end from the end reference voltage Vref at this time, works as output end
When for high level, electric current flows to the end reference voltage Vref from output end at this time, and due to the effect of positive-feedback circuit Rf, sluggishness is relatively
There are two threshold voltage, i.e., high threshold voltage and low threshold voltages by device L, in hysteresis comparator L, as long as voltage causes input to be believed
The amplitude of variation of number voltage is no more than lagging voltage, it is ensured that the stabilization of output state；The utility model structure is simple, operation
It is convenient, under the cooperation by controllable silicon SCR and hysteresis comparator L, so that switching circuit not only can protect circuit, avoid equipment
The frequency of Switching Power Supply when being damaged, and can be fluctuated near under-voltage protection setting voltage to avoid the input voltage of Switching Power Supply
It is numerous to be switched on or off, it ensure that the overall performance of Switching Power Supply.
In the utility model, the model LM339 of hysteresis comparator L, the resistance value difference of resistance R1, resistance R2 and resistance R3
For 5.1k Ω, 10k Ω, 5.1k Ω, the model of resistance R1, resistance R2 and resistance R3 are RT7X, and the capacitance of capacitor C is 68pF,
The model 1N4106 of the model CBB61 of capacitor C, voltage-stabiliser tube Z3, the model MCA12m of controllable silicon SCR rise when Uo1 is exported
Height, voltage-stabiliser tube Z3 breakdown conducting, the control terminal of controllable silicon SCR obtains trigger voltage, therefore controllable silicon SCR is connected, Uo2 voltage pair
Ground short circuit, current foldback circuit or short-circuit protection circuit will work, and stop the work of entire power circuit, when output overvoltage is existing
As excluding, silicon-controlled recovery off-state；When output end be low level when, due to hysteresis comparator L one end electric current very little and
Only nA grades, so being ignored, electric current flows to output end from the end reference voltage Vref at this time, when output end is high level,
Electric current flows to the end reference voltage Vref from output end at this time, and due to the effect of positive-feedback circuit Rf, there are two thresholds by hysteresis comparator L
Threshold voltage, i.e., high threshold voltage and low threshold voltage, in hysteresis comparator L, as long as voltage causes the change of applied signal voltage
Change amplitude is no more than lagging voltage, it is ensured that the stabilization of output state；The utility model structure is simple, easy to operate, passes through
Under the cooperation of controllable silicon SCR and hysteresis comparator L, so that switching circuit not only can protect circuit, equipment is avoided to be damaged,
And can to avoid Switching Power Supply input voltage under-voltage protection setting voltage near fluctuate when Switching Power Supply it is frequent open or
Shutdown, ensure that the overall performance of Switching Power Supply.
Working principle: increasing when Uo1 is exported, and voltage-stabiliser tube Z3 breakdown conducting, the control terminal of controllable silicon SCR obtains triggering electricity
Pressure, therefore controllable silicon SCR is connected, Uo2 voltage shorted to earth, current foldback circuit or short-circuit protection circuit will work, and stop
The work of entire power circuit, when the exclusion of output overvoltage phenomenon, silicon-controlled recovery off-state；When output end is low level,
Due to hysteresis comparator L one end electric current very little and only nA grades, so ignored, electric current is from the end reference voltage Vref at this time
Output end is flowed to, when output end is high level, electric current flows to the end reference voltage Vref from output end at this time, due to positive and negative feed
The effect of road Rf, there are two threshold voltage, i.e., high threshold voltage and low threshold voltages by hysteresis comparator L, in hysteresis comparator L
In, as long as voltage causes the amplitude of variation of applied signal voltage to be no more than lagging voltage, it is ensured that the stabilization of output state, leads to
It crosses under the cooperation of controllable silicon SCR and hysteresis comparator L, so that switching circuit not only can protect circuit, equipment is avoided to be damaged
It is bad, and can be to avoid the frequent unlatching of input voltage Switching Power Supply when fluctuation near under-voltage protection setting voltage of Switching Power Supply
Or shutdown, it ensure that the overall performance of Switching Power Supply.
The preferable specific embodiment of the above, only the utility model, but the protection scope of the utility model is not
It is confined to this, anyone skilled in the art is within the technical scope disclosed by the utility model, practical according to this
Novel technical solution and its utility model design are subject to equivalent substitution or change, should all cover the protection model in the utility model
Within enclosing.
Claims (7)
1. a kind of under-voltage protecting circuit with lag function, including capacitor C, which is characterized in that a termination of the capacitor C
The other end on ground, capacitor C is connected with one end of one end of controllable silicon SCR, voltage-stabiliser tube Z3, the other end connection of controllable silicon SCR
There is applied signal voltage Vin, one end of resistance R1 is connected on applied signal voltage Vin, the other end of resistance R1 is connected with electricity
One end of R3 and the anode of hysteresis comparator L are hindered, the other end of voltage-stabiliser tube Z3 is connected with reference voltage Vref, reference voltage Vref
On be connected with one end of resistance R2, the other end of resistance R2 is connected to the cathode of hysteresis comparator L, the first of hysteresis comparator L
Foot ground connection, the crus secunda of hysteresis comparator L are equipped with one end of positive feedback resistor Rf, and the other end of positive feedback resistor Rf is connected to
One end of R3.
2. a kind of under-voltage protecting circuit with lag function according to claim 1, which is characterized in that the sluggishness ratio
Model LM339 compared with device L.
3. a kind of under-voltage protecting circuit with lag function according to claim 1, which is characterized in that the resistance
The resistance value of R1, resistance R2 and resistance R3 are respectively 5.1k Ω, 10k Ω, 5.1k Ω.
4. a kind of under-voltage protecting circuit with lag function according to claim 1, which is characterized in that the resistance
The model of R1, resistance R2 and resistance R3 are RT7X.
5. a kind of under-voltage protecting circuit with lag function according to claim 1, which is characterized in that the capacitor C
Capacitance be 68pF, the model CBB61 of capacitor C.
6. a kind of under-voltage protecting circuit with lag function according to claim 1, which is characterized in that the voltage-stabiliser tube
The model 1N4106 of Z3.
7. a kind of under-voltage protecting circuit with lag function according to claim 1, which is characterized in that described silicon-controlled
The model MCA12m of SCR.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821568375.8U CN208753976U (en) | 2018-09-25 | 2018-09-25 | A kind of under-voltage protecting circuit with lag function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821568375.8U CN208753976U (en) | 2018-09-25 | 2018-09-25 | A kind of under-voltage protecting circuit with lag function |
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| Publication Number | Publication Date |
|---|---|
| CN208753976U true CN208753976U (en) | 2019-04-16 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201821568375.8U Active CN208753976U (en) | 2018-09-25 | 2018-09-25 | A kind of under-voltage protecting circuit with lag function |
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| CN (1) | CN208753976U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112653098A (en) * | 2020-12-24 | 2021-04-13 | 潍柴动力股份有限公司 | Battery output undervoltage protection circuit |
| CN113849438A (en) * | 2021-09-27 | 2021-12-28 | 浙江华创视讯科技有限公司 | Protection circuit, method of protecting circuit, storage medium, and electronic apparatus |
-
2018
- 2018-09-25 CN CN201821568375.8U patent/CN208753976U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112653098A (en) * | 2020-12-24 | 2021-04-13 | 潍柴动力股份有限公司 | Battery output undervoltage protection circuit |
| CN113849438A (en) * | 2021-09-27 | 2021-12-28 | 浙江华创视讯科技有限公司 | Protection circuit, method of protecting circuit, storage medium, and electronic apparatus |
| CN113849438B (en) * | 2021-09-27 | 2024-03-08 | 浙江华创视讯科技有限公司 | Protection circuit, method of protecting circuit, storage medium, and electronic device |
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