CN204144908U - Overheating protection circuit - Google Patents
Overheating protection circuit Download PDFInfo
- Publication number
- CN204144908U CN204144908U CN201420380363.8U CN201420380363U CN204144908U CN 204144908 U CN204144908 U CN 204144908U CN 201420380363 U CN201420380363 U CN 201420380363U CN 204144908 U CN204144908 U CN 204144908U
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- circuit
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- comparison circuit
- power supply
- comparator
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Abstract
The utility model provides a kind of overheating protection circuit, it comprises a temperature sensing circuit and a comparison circuit, described temperature sensing circuit connects described comparison circuit, described comparison circuit connects system or the power supply unit of electronic equipment by a switching circuit, this temperature sensing circuit has a thermistor collection be made up of multiple thermistor being arranged in series different region to be sensed on described mainboard, when the temperature that any one thermistor of described temperature sensing circuit senses the region to be sensed of its correspondence is more than a ceiling temperature value, described comparison circuit controls system or the power supply unit that described switching circuit cuts out described electronic equipment.By above-mentioned setting, overheating protection circuit of the present utility model can detect the temperature in multiple spot region simultaneously.
Description
Technical field
The utility model is a kind of overheating protection circuit.
Background technology
There is the thermometric protecting circuit designed of hysteresis characteristic at present; often can only detect the temperature in a region by set of circuits; one group of circuit cannot be utilized to detect multiple spot regional temperature simultaneously; moreover; mainboard has in some region Power Management Design again protection mechanism circuit automatic without IC time; when power supply part be short-circuited or other reasons and cause overheated time, often unprotect mechanism.
Summary of the invention
Main purpose of the present utility model is to provide a kind of overheating protection circuit, and it can detect the temperature in multiple spot region simultaneously.
For reaching above-mentioned purpose, the utility model provides a kind of overheating protection circuit, it comprises a temperature sensing circuit and a comparison circuit, described temperature sensing circuit connects described comparison circuit, described comparison circuit connects system or the power supply unit of electronic equipment by a switching circuit, this temperature sensing circuit has a thermistor collection be made up of multiple thermistor being arranged in series different region to be sensed on described mainboard, when the temperature that any one thermistor of described temperature sensing circuit senses the region to be sensed of its correspondence is more than a ceiling temperature value, described comparison circuit controls system or the power supply unit that described switching circuit cuts out described electronic equipment.
Preferably, described temperature sensing circuit has a power supply, a divider resistance and one first output further, one end ground connection of described thermistor collection, the other end connects described power supply by described divider resistance, and this first output is connected between this thermistor collection and this divider resistance.
Preferably, this comparison circuit is an existing anti-phase input type Shi Mite comparison circuit with hysteresis phenomenon, there is a comparator and one second output, the reverse input end of described comparator connects described first output, the positive input of described comparator connects power supply by the first resistance, and by the second grounding through resistance, the output of described comparator is connected to the positive input of described comparator by the 4th resistance, and form a node J, a upper limit threshold values and a lower limit threshold values is had in advance in described comparison circuit, when the voltage of the reverse input end of described comparator is greater than this upper limit threshold values, this comparator exports a low level, when the voltage of the reverse input end of described comparator is less than described lower limit threshold values, then the second output exports a high level, second output of described comparison circuit connects described switching circuit, when the output output low level of described comparison circuit, described switching circuit cuts out described power supply unit or system, when the output of described comparison circuit exports high level, described switching circuit controls power supply unit or system is normally run.
Compared with prior art; the temperature sensing circuit of overheating protection circuit of the present utility model is by the multiple thermistor being arranged on different region to be sensed on described mainboard of series connection; when the temperature that any one thermistor senses the region to be sensed of its correspondence is more than a ceiling temperature value; described comparison circuit controls system or the power supply unit that described switching circuit cuts out described electronic equipment, and the utility model can reach the beneficial effect of the temperature simultaneously detecting multiple spot region whereby.
[accompanying drawing explanation]
Fig. 1 is the circuit diagram of the utility model overheating protection circuit.
Fig. 2 is the characteristic schematic diagram of the utility model comparison circuit.
[embodiment]
Refer to shown in Fig. 1, a kind of overheating protection circuit of the utility model comprises a temperature sensing circuit 11 and comparison circuit 12, and it is applied on electronic equipment mainboard has in the land of Power Management Design again without the automatic protection mechanism of IC.Described comparison circuit 12 connects system or the power supply unit of electronic equipment by a switching circuit (not shown), when temperature sensing circuit 11 sense power supply part be short-circuited or other reasons and cause overheated time, described comparison circuit 12 can control described switching circuit direct powered-down supply or make system out of service, and when described temperature sensing circuit 11 sensed any power supply part overheated time, described comparison circuit 12 can control described switching circuit and open described power supply unit or system.
See also Fig. 2, this temperature sensing circuit 11 is for the temperature that senses on electronic equipment mainboard and have a thermistor collection R1 be made up of multiple thermistor THR being arranged in series different region to be sensed on described mainboard, a power supply VCC, a divider resistance R2 and one first output U1.One end ground connection of described thermistor collection R1, the other end connects described power supply VCC by described divider resistance R2, and then forms a bleeder circuit with described divider resistance R2.This first output U1 is connected between this thermistor collection R1 and this divider resistance R2.In the present embodiment, thermistor THR is positive temperature coefficient (positive temperature coefficient, PTC) type resistance, the resistance of this type is according to its linearity curve, and its resistance value just can will become suddenly many greatly when temperature exceedes a certain value.So, the voltage of this first output U1 will become very large when any one regional temperature to be measured exceedes a certain preset value in described difference region to be measured, and then for the change of sensing temperature.That is, when the temperature in region to be sensed arbitrary on described mainboard exceedes described a certain value, the voltage of described first output U1 will become greatly, and when region to be sensed arbitrary on described mainboard temperature reduce time, described first output U1 voltage will diminish.
This comparison circuit 12 is an existing anti-phase input type Shi Mite comparison circuit with hysteresis phenomenon, when the temperature that any one thermistor THR of described temperature sensing circuit 11 senses the region to be sensed of its correspondence is more than a ceiling temperature value, described comparison circuit 12 controls system or the power supply unit that described switching circuit cuts out described electronic equipment, in the present embodiment, described comparison circuit 12 has a comparator A and one second output U2, the reverse input end of described comparator A connects described first output U1, namely be connected between described thermistor collection R1 and described divider resistance R2.The positive input of described comparator A connects power supply VCC by the first resistance R3, and by the second resistance R4 ground connection.The output of described comparator A is connected to the positive input of described comparator A by the 4th resistance R5, and forms a node J.See also Fig. 2, according to the characteristic of described comparison circuit 12, an a upper limit threshold values UP1 and lower limit threshold values UP2 is had in advance in described comparison circuit 12, when the voltage (i.e. the voltage of the first output U1) of the reverse input end of described comparator A is greater than this upper limit threshold values UP1, this comparator A exports a low level, when the voltage of the reverse input end of described comparator A is less than described lower limit threshold values UP2, then the second output U2 exports a high level, second output U2 of described comparison circuit 12 connects described switching circuit, when the output U2 output low level of described comparison circuit 12, described switching circuit cuts out described power supply unit or system, and when the output U2 of described comparison circuit 12 exports high level, described switching circuit controls power supply unit or system is normally run.
In sum, the various embodiments described above and diagram are only the preferred embodiment of the utility model, when can not with the scope of restriction the utility model enforcement, the equalization change namely generally done according to the utility model claim with modify, all should belong in scope that the utility model patent contains.
Claims (3)
1. an overheating protection circuit, it comprises a temperature sensing circuit and a comparison circuit, described temperature sensing circuit connects described comparison circuit, described comparison circuit connects system or the power supply unit of electronic equipment by a switching circuit, it is characterized in that, this temperature sensing circuit has a thermistor collection be made up of multiple thermistor being arranged in series different region to be sensed on mainboard, when the temperature that any one thermistor of described temperature sensing circuit senses the region to be sensed of its correspondence is more than a ceiling temperature value, described comparison circuit controls system or the power supply unit that described switching circuit cuts out described electronic equipment.
2. overheating protection circuit according to claim 1; it is characterized in that; described temperature sensing circuit has a power supply, a divider resistance and one first output further; one end ground connection of described thermistor collection; the other end connects described power supply by described divider resistance, and this first output is connected between this thermistor collection and this divider resistance.
3. overheating protection circuit according to claim 2, it is characterized in that, described comparison circuit is an existing anti-phase input type Shi Mite comparison circuit with hysteresis phenomenon, there is a comparator and one second output, the reverse input end of described comparator connects described first output, the positive input of described comparator connects power supply by the first resistance, and by the second grounding through resistance, the output of described comparator is connected to the positive input of described comparator by the 4th resistance, and form a node, a upper limit threshold values and a lower limit threshold values is had in advance in described comparison circuit, when the voltage of the reverse input end of described comparator is greater than this upper limit threshold values, this comparator exports a low level, when the voltage of the reverse input end of described comparator is less than described lower limit threshold values, then the second output exports a high level, second output of described comparison circuit connects described switching circuit, when the output output low level of described comparison circuit, described switching circuit cuts out described power supply unit or system, when the output of described comparison circuit exports high level, described switching circuit controls power supply unit or system is normally run.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420380363.8U CN204144908U (en) | 2014-07-10 | 2014-07-10 | Overheating protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420380363.8U CN204144908U (en) | 2014-07-10 | 2014-07-10 | Overheating protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204144908U true CN204144908U (en) | 2015-02-04 |
Family
ID=52421573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420380363.8U Expired - Fee Related CN204144908U (en) | 2014-07-10 | 2014-07-10 | Overheating protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204144908U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107332208A (en) * | 2016-04-29 | 2017-11-07 | 华为技术有限公司 | A kind of protection circuit, mainboard guard method and terminal |
-
2014
- 2014-07-10 CN CN201420380363.8U patent/CN204144908U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107332208A (en) * | 2016-04-29 | 2017-11-07 | 华为技术有限公司 | A kind of protection circuit, mainboard guard method and terminal |
| CN107332208B (en) * | 2016-04-29 | 2019-08-27 | 华为技术有限公司 | A kind of protection circuit, mainboard guard method and terminal |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150204 Termination date: 20150710 |
|
| EXPY | Termination of patent right or utility model |