CN102751700A - Over-temperature protection circuit - Google Patents
Over-temperature protection circuit Download PDFInfo
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- CN102751700A CN102751700A CN2012102172944A CN201210217294A CN102751700A CN 102751700 A CN102751700 A CN 102751700A CN 2012102172944 A CN2012102172944 A CN 2012102172944A CN 201210217294 A CN201210217294 A CN 201210217294A CN 102751700 A CN102751700 A CN 102751700A
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Abstract
The invention relates to an over-temperature protection circuit which comprises a temperature detection circuit, a three-terminal voltage stabilizer and a control signal output circuit, wherein the output voltage of the temperature detection circuit decreases as the environment temperature increases; and the first terminal of the three-terminal voltage stabilizer is connected with the output end of the temperature detection circuit, the second terminal is connected to the ground, and the third terminal is connected with a direct current source through a resistor and connected with the control signal output circuit as the output end of the three-terminal voltage stabilizing circuit. When the voltage of the first terminal of the three-terminal voltage stabilizer is less than a first preset voltage, the three-terminal voltage stabilizer is stopped to output a high level to the control signal output circuit, so that the control signal output circuit outputs an over-temperature signal. The implementation of the over-temperature protection circuit provided by the invention does not need to adopt any power amplification chip, and only adopts resistors, capacitors, common switching tubes and one three-terminal voltage stabilizing integrated circuit; and thus, the invention has the advantages of simple circuit board layout and low cost. In addition, the over-temperature protection circuit is simple, and also has the advantages of novel conception and stable working performance.
Description
Technical field
The present invention relates to overheat protector control circuit in the electronic circuit.
Background technology
Thermal-shutdown circuit in the general electronics electronics road generally adopts thermistor, amplifier method relatively; Adopt the bridge-type equilibrium principle to accomplish the overheat protector function; Be primarily characterized in that and use the amplifier chip, thereby cause pcb board fabric swatch area big, and cost is higher.
Summary of the invention
The object of the present invention is to provide a kind of thermal-shutdown circuit that need not the power amplifier chip.
A kind of thermal-shutdown circuit, it comprises temperature sensing circuit, three terminal regulator and control signal output circuit that output voltage raises and reduces with ambient temperature.First end of said three terminal regulator links to each other with the output of temperature sensing circuit, its second end ground connection, and its 3rd end links to each other with DC source through resistance, and the output as the three-terminal voltage-stabilizing circuit links to each other with the control signal output loop simultaneously.When ambient temperature met or exceeded first preset temperature, the temperature sensing circuit output voltage was less than or equal to first predeterminated voltage.When the voltage of first end of three terminal regulator is equal to or greater than first predeterminated voltage; And three terminal regulator conducting when the voltage of its 3rd end is high level; When the voltage of first end of three terminal regulator during less than first predeterminated voltage its by; Thereby export a high level and give the control signal output circuit, make control signal output circuit output excess temperature signal.
In a preferred embodiment, described thermal-shutdown circuit also comprises the return difference circuit that links to each other with temperature sensing circuit with the control signal output circuit.When ambient temperature dropped to second preset temperature, the return difference circuit was controlled said three terminal regulator conducting, thereby made the control signal output circuit stop to export the excess temperature signal.Said second preset temperature is less than first preset temperature.
In a preferred embodiment, said temperature sensing circuit comprises sectional pressure element and temperature sensor; One end of said sectional pressure element links to each other with reference power supply, and its other end links to each other with an end of temperature sensor, and the while is as the output of temperature sensing circuit; The other end ground connection of temperature sensor.In a preferred embodiment, said sectional pressure element is a resistance.
In a preferred embodiment, said control signal output circuit comprises voltage stabilizing didoe, the 4th resistance and first switching tube; The negative electrode of voltage stabilizing didoe links to each other with the 3rd end of three terminal regulator, and its anode links to each other with first control end of switching tube through the 4th resistance; The first end ground connection of first switching tube, its second end is as the output of control signal output circuit; When the voltage stabilizing didoe conducting, the first switching tube conducting.
In a preferred embodiment, said return difference circuit comprises the 3rd resistance, the 5th resistance, first electric capacity, second electric capacity and second switch pipe; One end of the 3rd resistance links to each other with the anode of voltage stabilizing didoe, and its other end links to each other with the control end of second switch pipe and an end of first electric capacity; The other end ground connection of first electric capacity; The first end ground connection of second switch pipe, its second end links to each other with the output of temperature sensing circuit and an end of second electric capacity through the 5th resistance; The other end ground connection of second electric capacity.
Thermal-shutdown circuit of the present invention needn't adopt the amplifier chip, only adopts resistance, electric capacity, switching tube commonly used and a circuit of three-terminal voltage-stabilizing integrated can realize that the wiring board fabric swatch is simple, and is with low cost.In addition, this thermal-shutdown circuit is succinct, novel, stable work in work.
Description of drawings
Fig. 1 is the circuit structure schematic diagram of the thermal-shutdown circuit of an embodiment.
Embodiment
To combine specific embodiment and accompanying drawing that thermal-shutdown circuit of the present invention is described in further detail below.
Temperature protection circuit of the present invention mainly comprises temperature sensing circuit, three terminal regulator IC1, control signal output circuit and return difference circuit.
The output voltage of temperature sensing circuit raises with ambient temperature and reduces.When ambient temperature met or exceeded first preset temperature, the temperature sensing circuit output voltage was less than or equal to first predeterminated voltage, and three terminal regulator is by, control signal output circuit output excess temperature signal.When ambient temperature was less than or equal to second preset temperature, the temperature sensing circuit output voltage was more than or equal to second predeterminated voltage, and the return difference circuit makes the three terminal regulator conducting, and the control signal output circuit stops to export the excess temperature signal.Second preset temperature is less than first preset temperature.
A typical application is as shown in Figure 1, and temperature sensing circuit can comprise the series circuit of being made up of sectional pressure element R1 and temperature sensor RT.Sectional pressure element R1 is used for dividing potential drop, can be resistance, and temperature sensor RT adopts negative tempperature coefficient thermistor.The end of sectional pressure element R1 links to each other with reference power supply Vref, and its other end links to each other with the end of temperature sensor RT, and the while is as the output of temperature sensing circuit.The other end ground connection of temperature sensor RT.
Three terminal regulator IC1 is used for when the temperature sensing circuit output voltage is less than or equal to first predeterminated voltage, exporting an enabling signal to the control signal output circuit.The output of first end of three terminal regulator IC1 (pin of figure acceptance of the bid 1) and temperature sensing circuit; The tie point that also is sectional pressure element R1 and temperature sensor RT links to each other; Its second end (pin of figure acceptance of the bid 2) ground connection; Its 3rd end (pin of figure acceptance of the bid 3) links to each other with DC source VCC through resistance R 2, and the output as the three-terminal voltage-stabilizing circuit links to each other with the control signal output loop simultaneously.In the present embodiment, three terminal regulator IC1 adopts an integrated circuit.When the voltage of first end of three terminal regulator IC1 is equal to or greater than first predeterminated voltage; And three terminal regulator IC1 conducting when the voltage of its 3rd end is high level; When the resistance between its second end and the 3rd end after its conducting almost nil; Thereby the voltage of exporting approximate zero volt is given the control signal output circuit, and the control signal output circuit is not worked.When the voltage of first end of three terminal regulator IC1 during less than first predeterminated voltage three terminal regulator IC1 end, give the control signal output circuit thereby export a high level (being enabling signal), make control signal output circuit output excess temperature signal.
The control signal output circuit is used for output excess temperature signal after receiving enabling signal.In the present embodiment, as shown in Figure 1, the control signal output circuit comprises voltage stabilizing didoe Z1, the 4th resistance R 4 and the first switching tube Q1.The negative electrode of voltage stabilizing didoe Z1 links to each other with the 3rd end of three terminal regulator IC1, and its anode links to each other with the control end of the first switching tube Q1 through the 4th resistance R 4.The first end ground connection of the first switching tube Q1, its second end is as the output of control signal output circuit.When voltage stabilizing didoe Z1 conducting, the first switching tube Q1 conducting, output excess temperature signal (through the CTL end).In the present embodiment, the first switching tube Q1 adopts NPN type triode, and its control end is a base stage, and first end is an emitter, and second end is a collector electrode.Among other embodiment, can also adopt mosfet or IGBT.
The return difference circuit is used for when ambient temperature is less than or equal to second preset temperature, restarting temperature protection circuit, and the conducting of control three terminal regulator makes the control signal output circuit stop to export the excess temperature signal.In the present embodiment, the return difference circuit comprises the 3rd resistance R 3, the 5th resistance R 5, first capacitor C 1, second capacitor C 2 and second switch pipe Q2.One end of the 3rd resistance R 3 links to each other with the anode of voltage stabilizing didoe Z1, and its other end links to each other with the control end of second switch pipe Q2 and an end of first capacitor C 1.The other end ground connection of first capacitor C 1.The first end ground connection of second switch pipe Q2, its second end links to each other with the output of temperature sensing circuit and an end of second capacitor C 2 through the 5th resistance R 5.The other end ground connection of second capacitor C 2.In the present embodiment, second switch pipe Q2 adopts NPN type triode, and its control end is a base stage, and first end is an emitter, and second end is a collector electrode.Among other embodiment, can also adopt mosfet or IGBT.
Its operation principle is: when ambient temperature lower; During promptly less than first preset temperature; The resistance of temperature sensor RT is far above the resistance of sectional pressure element R1, and then the voltage of first end of three terminal regulator IC1 is higher than first predeterminated voltage (being its conducting voltage), three terminal regulator conducting; Voltage-stabiliser tube Z1 cathode potential approaches zero, and voltage-stabiliser tube Z1 ends.Along with the rising of ambient temperature, temperature sensor RT resistance can reduce rapidly, and the voltage of first end of three terminal regulator IC1 also decreases; When the voltage of first end of three terminal regulator IC1 was lower than first predeterminated voltage, three terminal regulator IC1 ended, and the cathode potential of voltage-stabiliser tube Z1 is a high level; Voltage-stabiliser tube Z1 conducting; The first switching tube Q1 and second switch pipe Q2 conducting, output excess temperature signal, first preset temperature is the overheat protector point.After the overheat protector action; Ambient temperature reduces gradually; Temperature sensor RT resistance raises gradually, but owing to second switch pipe Q2 behind the overheat protector is open-minded, the 5th electronics R5 is parallelly connected with temperature sensor RT; So first terminal voltage of three terminal regulator IC1 can not be higher than first predeterminated voltage at once, can regulate the size of return difference through the size of regulating the 5th resistance R 5.Through selecting suitable voltage-stabiliser tube Z1, can prevent that the first switching tube Q1 from misleading.The 3rd resistance R 3 and first capacitor C 1 strobe.
Wherein, overheat protector point is design so: along with temperature raises, the resistance of temperature sensor RT descends, and overheat protector starts when its voltage equals the conducting voltage (being made as V0) of three terminal regulator IC1.At this moment:
Then derive
.Therefore can increase resistance R 1 improved warm spot, reduced resistance R 1 and reduced warm spot.
Return difference design: when circuit carries out overheat protector; Second switch pipe Q2 conducting, it is parallelly connected with temperature sensor RT to be equivalent to the 5th resistance R 5, and protective circuit is recovered when its voltage reaches the conducting voltage of three terminal regulator IC1; The resistance of thermistor when design RT1 is recovery, at this moment:
Then derive
.Can regulate return difference through the resistance that changes the 5th resistance R 5, increase 5 of the 5th resistance R and reduce return difference, reduce 5 of the 5th resistance R and increase return difference.
The present invention is applicable to the overheat protector control of all electronic circuits, needn't adopt the amplifier chip, only adopts resistance, electric capacity, switching tube commonly used and a circuit of three-terminal voltage-stabilizing integrated can realize that the wiring board fabric swatch is simple, and is with low cost.In addition, this thermal-shutdown circuit is succinct, novel, stable work in work.
Though the description of this invention combines above specific embodiment to carry out,, those skilled in the art that can carry out many replacements, modification and variation according to above-mentioned content, be conspicuous.Therefore, all are such substitute, improve and change all is included in the spirit and scope of attached claim.
Claims (6)
1. a thermal-shutdown circuit is characterized in that, comprises temperature sensing circuit, three terminal regulator and control signal output circuit that output voltage raises and reduces with ambient temperature; First end of said three terminal regulator links to each other with the output of temperature sensing circuit, its second end ground connection, and its 3rd end links to each other with DC source through resistance, and the output as the three-terminal voltage-stabilizing circuit links to each other with the control signal output loop simultaneously; When ambient temperature met or exceeded first preset temperature, the temperature sensing circuit output voltage was less than or equal to first predeterminated voltage; When the voltage of first end of three terminal regulator is equal to or greater than first predeterminated voltage; And three terminal regulator conducting when the voltage of its 3rd end is high level; It ends during less than first predeterminated voltage when the voltage of first end of three terminal regulator; Thereby export a high level and give the control signal output circuit, make control signal output circuit output excess temperature signal.
2. thermal-shutdown circuit according to claim 1; It is characterized in that; Also comprise the return difference circuit that links to each other with temperature sensing circuit with the control signal output circuit; When ambient temperature dropped to second preset temperature, the return difference circuit was controlled said three terminal regulator conducting, thereby made the control signal output circuit stop to export the excess temperature signal; Said second preset temperature is less than first preset temperature.
3. thermal-shutdown circuit according to claim 1 and 2 is characterized in that said temperature sensing circuit comprises sectional pressure element and temperature sensor; One end of said sectional pressure element links to each other with reference power supply, and its other end links to each other with an end of temperature sensor, and the while is as the output of temperature sensing circuit; The other end ground connection of temperature sensor.
4. thermal-shutdown circuit according to claim 3 is characterized in that, said sectional pressure element is a resistance.
5. thermal-shutdown circuit according to claim 1 and 2 is characterized in that, said control signal output circuit comprises voltage stabilizing didoe, the 4th resistance and first switching tube; The negative electrode of voltage stabilizing didoe links to each other with the 3rd end of three terminal regulator, and its anode links to each other with first control end of switching tube through the 4th resistance; The first end ground connection of first switching tube, its second end is as the output of control signal output circuit; When the voltage stabilizing didoe conducting, the first switching tube conducting.
6. thermal-shutdown circuit according to claim 5 is characterized in that, said return difference circuit comprises the 3rd resistance, the 5th resistance, first electric capacity, second electric capacity and second switch pipe; One end of the 3rd resistance links to each other with the anode of voltage stabilizing didoe, and its other end links to each other with the control end of second switch pipe and an end of first electric capacity; The other end ground connection of first electric capacity; The first end ground connection of second switch pipe, its second end links to each other with the output of temperature sensing circuit and an end of second electric capacity through the 5th resistance; The other end ground connection of second electric capacity.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2012102172944A CN102751700A (en) | 2012-06-28 | 2012-06-28 | Over-temperature protection circuit |
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| CN2012102172944A CN102751700A (en) | 2012-06-28 | 2012-06-28 | Over-temperature protection circuit |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103840434A (en) * | 2012-11-22 | 2014-06-04 | 广东美的制冷设备有限公司 | Over-temperature protection circuit used for power module |
| CN104948489A (en) * | 2014-03-25 | 2015-09-30 | 海洋王（东莞）照明科技有限公司 | Temperature control switching circuit |
| CN104979806A (en) * | 2014-04-02 | 2015-10-14 | 江苏物联网研究发展中心 | IGBT over-temperature protecting circuit and protecting method thereof |
| CN107863073A (en) * | 2017-12-22 | 2018-03-30 | 深圳Tcl新技术有限公司 | LCOALDIMMING backlight drive circuits and display device |
| CN107919650A (en) * | 2017-10-26 | 2018-04-17 | 深圳市凌康技术股份有限公司 | A kind of thermal-shutdown circuit |
| CN108303193A (en) * | 2018-04-10 | 2018-07-20 | 国家电网公司 | A kind of connecting terminal overheating detection circuit and single-phase charge-controlled intelligent electric meter |
| CN109066594A (en) * | 2018-08-01 | 2018-12-21 | 珠海格力电器股份有限公司 | A kind of over-temperature protection device of motor, motor and its excess temperature protection method |
| CN109217258A (en) * | 2018-10-24 | 2019-01-15 | 广州金升阳科技有限公司 | A kind of control circuit |
| CN110571758A (en) * | 2019-08-05 | 2019-12-13 | 深圳市万普拉斯科技有限公司 | USB interface protection circuit, method, adapter and electronic equipment |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2861995Y (en) * | 2005-11-09 | 2007-01-24 | 颜陶 | Two thread environment and temperature sensor |
| CN200969055Y (en) * | 2006-10-24 | 2007-10-31 | 陈栋均 | Temperature, humidity, illumination controller |
| CN101707350A (en) * | 2009-10-21 | 2010-05-12 | 海洋王照明科技股份有限公司 | Overheat protection circuit and switch power supply circuit |
| US20100219784A1 (en) * | 2009-03-02 | 2010-09-02 | Chang Hsiu-Cheng | Method and circuit for controlling motor speed |
| CN201741054U (en) * | 2010-08-25 | 2011-02-09 | 王雁尘 | Temperature monitoring circuit formed by TL431 |
| CN102035191A (en) * | 2010-12-28 | 2011-04-27 | 广东易事特电源股份有限公司 | Igbt module over-temperature protection circuit |
| CN202276510U (en) * | 2011-09-23 | 2012-06-13 | 广州莱迪光电股份有限公司 | LED (light-emitting diode) lamp overheat protection circuit |
-
2012
- 2012-06-28 CN CN2012102172944A patent/CN102751700A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2861995Y (en) * | 2005-11-09 | 2007-01-24 | 颜陶 | Two thread environment and temperature sensor |
| CN200969055Y (en) * | 2006-10-24 | 2007-10-31 | 陈栋均 | Temperature, humidity, illumination controller |
| US20100219784A1 (en) * | 2009-03-02 | 2010-09-02 | Chang Hsiu-Cheng | Method and circuit for controlling motor speed |
| CN101707350A (en) * | 2009-10-21 | 2010-05-12 | 海洋王照明科技股份有限公司 | Overheat protection circuit and switch power supply circuit |
| CN201741054U (en) * | 2010-08-25 | 2011-02-09 | 王雁尘 | Temperature monitoring circuit formed by TL431 |
| CN102035191A (en) * | 2010-12-28 | 2011-04-27 | 广东易事特电源股份有限公司 | Igbt module over-temperature protection circuit |
| CN202276510U (en) * | 2011-09-23 | 2012-06-13 | 广州莱迪光电股份有限公司 | LED (light-emitting diode) lamp overheat protection circuit |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103840434A (en) * | 2012-11-22 | 2014-06-04 | 广东美的制冷设备有限公司 | Over-temperature protection circuit used for power module |
| CN103840434B (en) * | 2012-11-22 | 2017-08-25 | 广东美的制冷设备有限公司 | A kind of thermal-shutdown circuit for power model |
| CN104948489A (en) * | 2014-03-25 | 2015-09-30 | 海洋王（东莞）照明科技有限公司 | Temperature control switching circuit |
| CN104979806A (en) * | 2014-04-02 | 2015-10-14 | 江苏物联网研究发展中心 | IGBT over-temperature protecting circuit and protecting method thereof |
| CN104979806B (en) * | 2014-04-02 | 2018-02-02 | 江苏物联网研究发展中心 | A kind of IGBT thermal-shutdown circuits and guard method |
| CN107919650A (en) * | 2017-10-26 | 2018-04-17 | 深圳市凌康技术股份有限公司 | A kind of thermal-shutdown circuit |
| CN107863073A (en) * | 2017-12-22 | 2018-03-30 | 深圳Tcl新技术有限公司 | LCOALDIMMING backlight drive circuits and display device |
| CN107863073B (en) * | 2017-12-22 | 2022-07-29 | 深圳Tcl新技术有限公司 | LCOALDIMMING backlight driving circuit and display device |
| CN108303193A (en) * | 2018-04-10 | 2018-07-20 | 国家电网公司 | A kind of connecting terminal overheating detection circuit and single-phase charge-controlled intelligent electric meter |
| CN108303193B (en) * | 2018-04-10 | 2023-11-07 | 国家电网公司 | Binding post overheat detection circuit and single-phase charge control intelligent ammeter |
| CN109066594A (en) * | 2018-08-01 | 2018-12-21 | 珠海格力电器股份有限公司 | A kind of over-temperature protection device of motor, motor and its excess temperature protection method |
| CN109217258A (en) * | 2018-10-24 | 2019-01-15 | 广州金升阳科技有限公司 | A kind of control circuit |
| CN110571758A (en) * | 2019-08-05 | 2019-12-13 | 深圳市万普拉斯科技有限公司 | USB interface protection circuit, method, adapter and electronic equipment |
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Application publication date: 20121024 |