CN201349121Y - Direct current input overvoltage and under-voltage protection circuit - Google Patents

Direct current input overvoltage and under-voltage protection circuit Download PDF

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Publication number
CN201349121Y
CN201349121Y CNU2008202358529U CN200820235852U CN201349121Y CN 201349121 Y CN201349121 Y CN 201349121Y CN U2008202358529 U CNU2008202358529 U CN U2008202358529U CN 200820235852 U CN200820235852 U CN 200820235852U CN 201349121 Y CN201349121 Y CN 201349121Y
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China
Prior art keywords
voltage
transistor
input
output
overvoltage
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Expired - Fee Related
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CNU2008202358529U
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Chinese (zh)
Inventor
白欣
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Shenzhen Coship Electronics Co Ltd
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Shenzhen Coship Electronics Co Ltd
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Priority to CNU2008202358529U priority Critical patent/CN201349121Y/en
Application granted granted Critical
Publication of CN201349121Y publication Critical patent/CN201349121Y/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

A direct current input overvoltage and under-voltage protection circuit comprises a first voltage and a second voltage comparators, a first transistor connected between input voltage and output voltage, and a second transistor whose collecting electrode is coupled with the grid electrode of the first transistor, wherein the base electrode of the second transistor is coupled with the output end of the second voltage comparator. When the input voltage is too high, the first voltage comparator outputs high voltage signals to lead a fourth transistor to be conducted, and the second and the first transistors are pulled to stop, and the output of the output voltage is disconnected, the base electrode of the fourth transistor is coupled with the output end of the first voltage comparator, and the collecting electrode of the fourth transistor is connected with the base electrode of the second transistor. When the input voltage is too low, the second voltage comparator outputs low voltage signals to lead the second transistor to stop, and the first transistor is pulled to stop, and the output of the output voltage is disconnected. The direct current input overvoltage and under-voltage protection circuit has the advantages of simple circuit, lower realization cost and higher reliability, which is especially suitable for the input overvoltage and under-voltage and the overvoltage control protection of a direct current input power supply or an accumulator.

Description

The overvoltage and the under-voltage protecting circuit of direct current input
Technical field
The utility model relates to a kind of input voltage protection circuit, especially relates to a kind of overvoltage and under-voltage protecting circuit of DC input voitage.
Background technology
DC low-voltage input overvoltage commonly used at present and under-voltage protecting circuit are to detect voltage by the amplifier comparator then control signal to be transferred to PWM chip realization control.As shown in Figure 1, C1, C2, C3 are filter capacitor, and U1A and U1B are operational amplifier, and its output is connected in series respectively after diode D1, the D2 of unidirectional conducting, export control signal by resistance R 1 to pwm chip.Wherein, be connected between input voltage and the ground, Chuan Jie resistance R 2 and voltage-stabiliser tube ZD1 mutually, and the C3 that is connected between resistance R 2 and voltage-stabiliser tube ZD1 common port and the ground provides range of safety operation for operational amplifier U1A; The pressurizer U2 that three ends are adjustable provides reference voltage for operational amplifier U1A.Constitute the testing circuit of a under-voltage protection by pressurizer U2, current-limiting resistance R4, resistance R 5 and R7, operational amplifier U1B and diode D1; Pressurizer U2, resistance R 4, resistance R 3, resistance R 6, operational amplifier U1A and diode D2 constitute the circuit that overvoltage detects, and the detection pin that outputs control signals to pwm chip through resistance R 1 comes on-off switching tube to realize circuit protection.
Foregoing circuit needs the support of the pwm chip protection of rear end, has taken pwm chip to rear end defencive function utilization, makes and realizes that cost is higher; And front-end protection part and the unseparated mode in rear end exist circuit complexity, failure rate and get rid of the defective that difficulty increases.
The utility model content
The utility model is to propose a kind of overvoltage and under-voltage protecting circuit of DC input voitage, to simplify circuit, improves the reliability of circuit.
For solving technical problem of the present utility model, the utility model discloses a kind of overvoltage and under-voltage protecting circuit of direct current input, comprising:
Positive input terminal all connects first, second voltage comparator of the pressurizer that reference voltage is provided respectively by divider resistance connection input voltage, negative input end;
Be connected the first transistor between input voltage and the output voltage;
Collector electrode couples the transistor seconds of the first transistor grid, and the base stage of transistor seconds couples the output of second voltage comparator; When input voltage was too high, the first voltage comparator output HIGH voltage signal made the 4th transistor turns, and pulling second, the first transistor end and the output of disconnection output voltage;
Base stage couples the 4th transistor of the first voltage comparator output, and the 4th transistor collector connects the base stage of transistor seconds; Cross when low when input voltage, the second voltage comparator output LOW voltage signal ends transistor seconds, the pulling the first transistor by and disconnect the output of output voltage.
Preferably, the overvoltage and the under-voltage protecting circuit of described direct current input also comprise: base stage receives the 3rd transistor of external control signal, its grounded emitter, and collector electrode connects the base stage of transistor seconds.
Preferably, the first transistor is the MOS transistor of P raceway groove, and second, third and the 4th transistor are the triode of NPN type.
Preferably, the grid of the first transistor serial connection current-limiting resistance; Second, third is connected current-limiting resistance and pull down resistor respectively with the 4th transistorized base stage.
Preferably, be connected in series second voltage-stabiliser tube between the grid of the first transistor and the input voltage, and the protective resistance in parallel with second voltage-stabiliser tube.
Preferably, the overvoltage and the under-voltage protecting circuit of described direct current input also comprise: be serially connected in the filter capacitor between input voltage and the ground; Be serially connected in the filter capacitor between output voltage and the ground.
Compared with prior art, the utlity model has following beneficial effect:
The utility model especially is fit to be applied to direct-current input power supplying or storage battery input overvoltage/undervoltage and the protection that detects from the overcurrent of back-end system, overheated, fault, emergent etc. or the mistake pressure-controlled of external circuit handoff functionality; can be used in the power supply input front end separately and realize its claimed function; and do not need the support of rear end control chip protection, thereby it is simple and realize the advantage of the low and higher reliability of cost to have a circuit.
Description of drawings
Fig. 1 is the structural representation of existing direct current input overvoltage and under-voltage protecting circuit;
Fig. 2 is the direct current input overvoltage that the utility model proposes and the structural representation of under-voltage protecting circuit.
Embodiment
The utility model is independent with the defencive function of direct current importation, and the switching tube turn-off protection that utilizes driving power front end importation to increase is used for direct-current input power supplying or storage battery input overvoltage/undervoltage and detects protection; And external control signal can reach the power supply that cuts off input from the control of the overcurrent of back-end system, overheated, fault, detection such as emergent and external circuit handoff functionality, and protection rear end equipment or input power supply switch purpose.
Show as Fig. 2.Circuit of the present utility model comprises: be connected the filter capacitor C1 between input voltage vin and the ground (GND), be connected the filter capacitor C2 between output voltage V out and the ground; Be connected the first transistor Q1 of the P raceway groove between input voltage vin and the output voltage V out, the grid of this first transistor Q1 connects driving resistor R12, and be connected the second voltage-stabiliser tube ZD2 that is used to limit the first transistor Q1 gate source voltage between grid and the input voltage vin, and the protective resistance R1 that prevents that the first transistor Q1 from misleading of being used in parallel with the second voltage-stabiliser tube ZD2; Adopt first, second voltage comparator U1A and the U1B of homophase operational amplifier, the positive input terminal of the first voltage comparator U1A connects the common port of divider resistance R3 and R6, the negative input end of the first voltage comparator U1A connects the adjustable pressurizer U2 of three ends, and this pressurizer U2 is connected with input voltage vin by current-limiting resistance R4, and the positive input terminal of the second voltage comparator U1B connects the common port of divider resistance R5 and R7, and the negative input end of the second voltage comparator U1B connects pressurizer U2; The output of the second voltage comparator U1B is by the collector electrode of base stage and the 3rd, the 4th transistor Q3 and the Q4 of current-limiting circuit R10 connection transistor seconds Q2, and the collector electrode of transistor seconds Q2 connects the grid of the first transistor Q1 by resistance R 12; The output of the first voltage comparator U1A connects the base stage of the 4th transistor Q4 by current-limiting circuit R8; In addition, second, third is NPN type triode with the 4th transistor Q2, Q3 and Q4, and the equal ground connection of its emitter, and base stage meets pull down resistor R9, R13 and R11 respectively.
In addition, the circuit of utility model also comprises: be connected between input voltage vin and ground (GND) the first voltage-stabiliser tube ZD1 and the resistance R 2 of serial connection mutually, and the common port of the first voltage-stabiliser tube ZD1 and resistance R 2 is connected the power supply VCC end of the first voltage comparator U1A, and also is connected a filter capacitor C3 between the power supply VCC of the first voltage comparator U1A and the ground; The first voltage-stabiliser tube ZD1, resistance R 2 and filter capacitor C3 provide the trouble free service voltage range for the first voltage-stabiliser tube ZD1.
Operation principle of the present utility model is as follows:
1, when input voltage vin is in normal range (NR), the 3rd, the 4th transistor Q3, not conducting of Q4, the Q2 conducting, the grid of the first transistor Q1 is low level and conducting, the first transistor Q1 so input voltage vin is flowed through and output voltage V out.
2; when input voltage vin is on the low side; the voltage (reference voltage that provides for pressurizer U2) of voltage and its negative input end that is divided to the positive input terminal of the second voltage comparator U1B by divider resistance R5 and R7 is compared; the voltage of positive input terminal is lower than the voltage of negative input end; so reverse voltage signal (low-potential signal of the output of second voltage comparator U1B output; such as being-voltage signal of 12V) to transistor seconds Q2; make not conducting of transistor seconds Q2; and the grid of the first transistor Q1 is a high level; then not conducting of the first transistor Q1; thereby cut off input voltage vin to the path between the output voltage V out, reached the under-voltage protection purpose.Therefore, resistance R 4, pressurizer U2, divider resistance R5 and R7, the second voltage comparator U1B, resistance R 10, transistor seconds Q2 and the first transistor Q1 constitute under-voltage detection protective circuit.
3, when input voltage vin is too high, by comparing to the voltage of the positive input terminal of the first voltage comparator U1A and the voltage of its negative input end (reference voltage that provides for pressurizer U2) after divider resistance R3 and the R6 dividing potential drop, the voltage of positive input terminal is higher than the voltage of negative input end, so forward voltage signal (high potential signal of the output of first voltage comparator U1A output, such as being+voltage signal of 12V) to the 4th transistor Q4, make the 4th transistor Q4 conducting, the base voltage that further makes transistor seconds Q2 is dragged down and is made not conducting of transistor seconds Q2; Because not conducting of transistor seconds Q2 makes not conducting of the first transistor Q1, thereby has cut off input voltage vin to the path between the output voltage V out, reaches the purpose of overvoltage protection.Therefore, resistance R 4, pressurizer U2, divider resistance R3 and R6, the first voltage comparator U1A, resistance R 8, the 4th transistor Q4, transistor seconds Q2 and the first transistor Q1 constitute under-voltage detection protective circuit.
And, the base stage of the 3rd transistor Q3 receives external control signal by current-limiting resistance R11, when external control signal passes through the overcurrent from the rear end equipment system, overheated, fault, the emergent grade detected generation forward voltage signal, or when realizing the control forward voltage signal of another power supply input circuit handoff functionality, drive the 3rd transistor Q3, when the 3rd transistor Q3 conducting, the base voltage of transistor seconds Q2 is dragged down, make not conducting of transistor seconds Q2, then not conducting of the first transistor Q1, thus input voltage vin cut off to the path between the output voltage V out.
To sum up, the utility model especially is fit to be applied to direct-current input power supplying or battery input overvoltage/undervoltage and from back-end system The protection that overcurrent, overheated, fault, emergent etc. detects or the mistake pressure-controlled of external circuit handoff functionality can be used in separately electricity The source input front end is realized its claimed function, and does not need the support of rear end control chip protection, thereby it is simple to have a circuit With the advantage of realization cost than low and higher reliability.

Claims (7)

1, a kind of overvoltage and under-voltage protecting circuit of direct current input comprise: positive input terminal all connects first, second voltage comparator (U1A and U1B) of the pressurizer (U2) that reference voltage is provided respectively by divider resistance connection input voltage (Vin), negative input end; It is characterized in that, also comprise:
Be connected the first transistor (Q1) between input voltage (Vin) and the output voltage (Vout);
Collector electrode couples the transistor seconds (Q2) of the first transistor (Q1) grid, and the base stage of transistor seconds (Q2) couples the output of second voltage comparator (U1B); When input voltage (Vin) was too high, first voltage comparator (U1A) output HIGH voltage signal made the 4th transistor (Q4) conducting, and pulling second, the first transistor (Q2 and Q1) end and the output of disconnection output voltage (Vout);
Base stage couples the 4th transistor (Q4) of first voltage comparator (U1A) output, and the 4th transistor (Q4) collector electrode connects the base stage of transistor seconds (Q2); Cross when low when input voltage (Vin), second voltage comparator (U1B) output LOW voltage signal ends transistor seconds (Q2), pulling the first transistor (Q1) by and disconnect the output of output voltage (Vout).
2, according to the overvoltage and the under-voltage protecting circuit of the described direct current input of claim 1, it is characterized in that, also comprise: base stage receives the 3rd transistor (Q3) of external control signal, its grounded emitter, and collector electrode connects the base stage of transistor seconds (Q2).
3, according to the overvoltage and the under-voltage protecting circuit of the described direct current input of claim 2, it is characterized in that the first transistor (Q1) is the MOS transistor of P raceway groove, second, third and the 4th transistor (Q2, Q3 and Q4) are the triode of NPN type.
4, according to the overvoltage and the under-voltage protecting circuit of the described direct current input of claim 3, it is characterized in that the grid serial connection current-limiting resistance (R12) of the first transistor (Q1); Second, third base stage with the 4th transistor (Q2, Q3 and Q4) is connected current-limiting resistance (R10, R11 and R8) and pull down resistor (R9, R13 and R11) respectively.
5, overvoltage and the under-voltage protecting circuit of importing according to the described direct current of claim 1; it is characterized in that; be connected in series second voltage-stabiliser tube (ZD2) between the grid of the first transistor (Q1) and the input voltage (Vin), and the protective resistance (R1) in parallel with second voltage-stabiliser tube (ZD2).
6, according to the overvoltage and the under-voltage protecting circuit of the described direct current input of claim 1, it is characterized in that, also comprise: be serially connected in the filter capacitor (C1) between input voltage (Vin) and the ground.
7, according to the overvoltage and the under-voltage protecting circuit of the described direct current input of claim 1, it is characterized in that, also comprise: be serially connected in the filter capacitor (C2) between output voltage (Vout) and the ground.
CNU2008202358529U 2008-12-29 2008-12-29 Direct current input overvoltage and under-voltage protection circuit Expired - Fee Related CN201349121Y (en)

Priority Applications (1)

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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNU2008202358529U CN201349121Y (en) 2008-12-29 2008-12-29 Direct current input overvoltage and under-voltage protection circuit

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Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012079220A1 (en) * 2010-12-14 2012-06-21 Nokia Corporation Method and apparatus for providing under voltage protection for lifepo4 battery
CN102608371A (en) * 2012-04-13 2012-07-25 中达电通股份有限公司 Storage battery detecting device and undervoltage protection method thereof
CN102801138A (en) * 2011-05-25 2012-11-28 海洋王照明科技股份有限公司 Light-emitting diode (LED) over current protection circuit and light fitting
CN102801135A (en) * 2012-08-20 2012-11-28 深圳市大乘科技有限公司 Low-voltage and under-voltage shoot-through over-voltage protective current limiting circuit
CN103080759A (en) * 2010-09-10 2013-05-01 三菱电机株式会社 Overvoltage detecting device for energy storage module
CN103606900A (en) * 2013-10-22 2014-02-26 徐州市恒源电器有限公司 Lithium battery charging protection circuit
CN104466901A (en) * 2013-09-25 2015-03-25 深圳市海洋王照明工程有限公司 Low-voltage protection circuit
CN104505807A (en) * 2014-12-10 2015-04-08 无锡必创传感科技有限公司 Automobile sensor protection circuit
CN104577963A (en) * 2014-08-13 2015-04-29 浪潮电子信息产业股份有限公司 Method for designing input power protective circuit of server
CN104617549A (en) * 2015-02-06 2015-05-13 青岛歌尔声学科技有限公司 Overvoltage protecting circuit and electronic product
CN104682341A (en) * 2013-11-28 2015-06-03 海洋王(东莞)照明科技有限公司 Over-voltage/low-voltage protective circuit
CN105305797A (en) * 2015-10-15 2016-02-03 中国兵器工业集团第二一四研究所苏州研发中心 Overvoltage and undervoltage protection circuit for output of DC/DC power supply
CN105633904A (en) * 2016-02-04 2016-06-01 青岛海信电器股份有限公司 Switch circuit for protective circuit and terminal
CN105846402A (en) * 2016-06-01 2016-08-10 江苏安纳金机械有限公司 Power source protection circuit
CN106502300A (en) * 2017-01-05 2017-03-15 电子科技大学 A kind of over under-voltage protection circuit without the need for comparison voltage
CN109861176A (en) * 2018-12-20 2019-06-07 上海华兴数字科技有限公司 Electric power management circuit and system
CN112018738A (en) * 2020-08-07 2020-12-01 中国北方发动机研究所(天津) Sensor power supply interface circuit with overcurrent protection

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103080759A (en) * 2010-09-10 2013-05-01 三菱电机株式会社 Overvoltage detecting device for energy storage module
WO2012079220A1 (en) * 2010-12-14 2012-06-21 Nokia Corporation Method and apparatus for providing under voltage protection for lifepo4 battery
CN102801138A (en) * 2011-05-25 2012-11-28 海洋王照明科技股份有限公司 Light-emitting diode (LED) over current protection circuit and light fitting
CN102801138B (en) * 2011-05-25 2015-02-04 海洋王照明科技股份有限公司 Light-emitting diode (LED) over current protection circuit and light fitting
CN102608371B (en) * 2012-04-13 2014-08-13 中达电通股份有限公司 Storage battery detecting device and undervoltage protection method thereof
CN102608371A (en) * 2012-04-13 2012-07-25 中达电通股份有限公司 Storage battery detecting device and undervoltage protection method thereof
CN102801135A (en) * 2012-08-20 2012-11-28 深圳市大乘科技有限公司 Low-voltage and under-voltage shoot-through over-voltage protective current limiting circuit
CN102801135B (en) * 2012-08-20 2014-10-22 深圳市大乘科技有限公司 Low-voltage and under-voltage shoot-through over-voltage protective current limiting circuit
CN104466901A (en) * 2013-09-25 2015-03-25 深圳市海洋王照明工程有限公司 Low-voltage protection circuit
CN104466901B (en) * 2013-09-25 2019-02-05 深圳市海洋王照明工程有限公司 A kind of low-voltage protection circuit
CN103606900A (en) * 2013-10-22 2014-02-26 徐州市恒源电器有限公司 Lithium battery charging protection circuit
CN104682341A (en) * 2013-11-28 2015-06-03 海洋王(东莞)照明科技有限公司 Over-voltage/low-voltage protective circuit
CN104577963A (en) * 2014-08-13 2015-04-29 浪潮电子信息产业股份有限公司 Method for designing input power protective circuit of server
CN104505807A (en) * 2014-12-10 2015-04-08 无锡必创传感科技有限公司 Automobile sensor protection circuit
CN104617549A (en) * 2015-02-06 2015-05-13 青岛歌尔声学科技有限公司 Overvoltage protecting circuit and electronic product
CN105305797A (en) * 2015-10-15 2016-02-03 中国兵器工业集团第二一四研究所苏州研发中心 Overvoltage and undervoltage protection circuit for output of DC/DC power supply
CN105305797B (en) * 2015-10-15 2017-11-14 中国兵器工业集团第二一四研究所苏州研发中心 A kind of DC/DC power supplys output overvoltage under-voltage protecting circuit
CN105633904A (en) * 2016-02-04 2016-06-01 青岛海信电器股份有限公司 Switch circuit for protective circuit and terminal
CN105633904B (en) * 2016-02-04 2019-01-29 青岛海信电器股份有限公司 Protect the switching circuit and terminal of circuit
CN105846402A (en) * 2016-06-01 2016-08-10 江苏安纳金机械有限公司 Power source protection circuit
CN106502300A (en) * 2017-01-05 2017-03-15 电子科技大学 A kind of over under-voltage protection circuit without the need for comparison voltage
CN109861176A (en) * 2018-12-20 2019-06-07 上海华兴数字科技有限公司 Electric power management circuit and system
CN112018738A (en) * 2020-08-07 2020-12-01 中国北方发动机研究所(天津) Sensor power supply interface circuit with overcurrent protection

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Granted publication date: 20091118

Termination date: 20141229

EXPY Termination of patent right or utility model