CN204631648U - A kind of temperature protection circuit - Google Patents

Abstract

The utility model discloses a kind of temperature protection circuit, comprise the first chip U1, first triode Q1, first resistance R1, second resistance R2, 3rd resistance R3, 4th resistance R4, first temp-sensing element and the first blower module, wherein, first pin of the first chip U1 is connected with one end of the 4th resistance R4, the other end of the 4th resistance R4 is connected with the base stage of the first triode Q1, the emitter of the first triode Q1 is held with ground and is connected, the collector of the first triode Q1 is connected with the first blower module, first blower module is also connected with the feeder ear of external power supply module.Temperature protection circuit circuit structure of the present utility model is simple, dispel the heat, thus guaranteed output devices function is in normal temperature interval, substantially increases the serviceable life of circuit to opening fan fast during variation of ambient temperature to power device.

Description

A kind of temperature protection circuit

Technical field

The utility model relates to a kind of protection circuit, particularly relates to a kind of temperature protection circuit.

Background technology

In various in powerful circuit application, usually due to fault or environment temperature is too high causes the component element long period in circuit to work in high temperature environments, and then greatly have impact on the serviceable life of components and parts.General in power circuit, temperature protection circuit is mainly in order to prevent prime boost power pipe, high-speed rectifier two pole and rear class inverter power tube pipe constant power long term device work in dangerous temperature zone, but prior art temperature protection circuit is read digital temperature sensor mainly through single-chip microcomputer or is detected the mode testing temperature of voltage by single-chip microcomputer and D/A converter module, but digital temperature sensor and single-chip microcomputer D/A converter module need necessarily to measure the reaction time, temperature protection situation not in time may be caused, and there is the higher problem of cost in single-chip microcomputer D/A converter module.

Therefore, for the above-mentioned defect existed in currently available technology, be necessary to study in fact, to provide a kind of scheme, solve the defect existed in prior art.

Utility model content

In order to overcome the defect that prior art exists, the necessary one that provides is to the swift temperature protection circuit of temperature variation, thus guaranteed output devices function is in normal temperature interval, substantially increases the serviceable life of circuit.

In order to solve the problem of prior art, the technical solution of the utility model is:

A kind of temperature protection circuit, is characterized in that, comprise the first chip U1, the first triode Q1, the first resistance R1, the second resistance R2, the 3rd resistance R3, the 4th resistance R4, the first temp-sensing element and the first blower module, wherein,

First pin of described first chip U1 is connected with one end of described 4th resistance R4, the other end of described 4th resistance R4 is connected with the base stage of described first triode Q1, the emitter of described first triode Q1 is held with ground and is connected, the collector of described first triode Q1 is connected with described first blower module, and described first blower module is also connected with the feeder ear of external power supply module;

One end of 8th pin of described first chip U1, one end of described 3rd resistance R3, described second resistance R2 is connected with the reference edge of external power supply module jointly; The other end of described 3rd resistance R3 is connected with second pin of described first temp-sensing element with described first chip U1, and described first temp-sensing element is also connected with ground end; The other end of described second resistance R2 is connected with the 3rd pin of described first chip U1 with one end of described first resistance R1, and the other end of described first resistance R1 is held with ground and is connected.

Preferably, also comprise the second triode Q2, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the second temp-sensing element and the second blower module, wherein,

7th pin of described first chip U1 is connected with one end of described 8th resistance R8, the other end of described 8th resistance R8 is connected with the base stage of described second triode Q2, the emitter of described second triode Q2 is held with ground and is connected, the collector of described second triode Q2 is connected with described second blower module, and described second blower module is also connected with the feeder ear of external power supply module;

One end of described 7th resistance R7, one end of described 6th resistance R6 are connected with the reference edge of external power supply module jointly; The other end of described 7th resistance R7 is connected with the 6th pin of described second temp-sensing element with described first chip U1, and described second temp-sensing element is also connected with ground end; The other end of described 6th resistance R6 is connected with the 5th pin of described first chip U1 with one end of described 5th resistance R5, and the other end of described 5th resistance R5 is held with ground and is connected.

Preferably, described first chip U1 adopts LM258.

Preferably, described first temp-sensing element and described second temp-sensing element are NTC negative thermistor.

Compared with prior art; temperature protection circuit circuit structure of the present utility model is simple; to fan can be opened fast during variation of ambient temperature, power device is dispelled the heat, thus guaranteed output devices function is in normal temperature interval, substantially increases the serviceable life of circuit.

Accompanying drawing explanation

Fig. 1 is the circuit theory diagrams of the utility model temperature protection circuit.

Following specific embodiment will further illustrate the utility model in conjunction with above-mentioned accompanying drawing.

Embodiment

What provide the utility model below with reference to accompanying drawing is described further.

See Fig. 1, be depicted as the circuit theory diagrams of the utility model temperature protection circuit, comprise the first chip U1, first triode Q1, first resistance R1, second resistance R2, 3rd resistance R3, 4th resistance R4, first temp-sensing element and the first blower module, wherein, first pin of the first chip U1 is connected with one end of the 4th resistance R4, the other end of the 4th resistance R4 is connected with the base stage of the first triode Q1, the emitter of the first triode Q1 is held with ground and is connected, the collector of the first triode Q1 is connected with the first blower module, first blower module is also connected with the feeder ear of external power supply module, one end of 8th pin of the first chip U1, one end of the 3rd resistance R3, the second resistance R2 is connected with the reference edge of external power supply module jointly, the other end of the 3rd resistance R3 is connected with second pin of the first temp-sensing element with the first chip U1, and the first temp-sensing element is also connected with ground end, the other end of the second resistance R2 is connected with the 3rd pin of the first chip U1 with one end of the first resistance R1, and the other end of the first resistance R1 is held with ground and is connected.

In a preferred embodiment, the first chip U1 adopts LM258.Build a comparator circuit by LM258 chip, compare temp-sensing element signal and reference signal, it is strong that this circuit has antijamming capability, sensitivity advantages of higher.

In a preferred embodiment, first temp-sensing element is NTC negative thermistor, the resistance of the first resistance R1 is set to 12K ohm, the resistance of the second resistance R2 is set to 47K ohm, the resistance of the 3rd resistance R3 is set to 20K ohm, the resistance of the 4th resistance R4 is set to 4.7K ohm, the reference voltage that power supply exports is 5V, during circuit original state, the voltage on the first chip U1 pin 3 equals 5V*12/ (12+47), approximates 1V.First chip U1 pin 2 connects 10K NTC negative thermistor to ground, the collector output mouth of the first triode Q1 connects heat radiation fan module to power module power supply side 12V output terminal, during 25 DEG C of room temperatures, pin 2 voltage is greater than 1V, 1 pin output low level, triode is in cut-off state, and now fan does not start.When about temperature rise to 65 DEG C, 2 pin voltages are less than 1V gradually, and now 1 pin starts to export high level and drives triode ON, and radiator fan starts normal startup.When temperature drops to below setting, fan speed slows down gradually to 0.

Due to LM358 amplifier band two-way comparator circuit; in order to make full use of resources of chip; in a preferred embodiment; temperature protection circuit also comprises the second triode Q2, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the second temp-sensing element and the second blower module; wherein

7th pin of the first chip U1 is connected with one end of the 8th resistance R8, the other end of the 8th resistance R8 is connected with the base stage of the second triode Q2, the emitter of the second triode Q2 is held with ground and is connected, the collector of the second triode Q2 is connected with the second blower module, and the second blower module is also connected with the feeder ear of external power supply module;

One end of 7th resistance R7, one end of the 6th resistance R6 are connected with the reference edge of external power supply module jointly; The other end of the 7th resistance R7 is connected with the 6th pin of the first chip U1 with the second temp-sensing element, and the second temp-sensing element is also connected with ground end; The other end of the 6th resistance R6 is connected with the 5th pin of the first chip U1 with one end of the 5th resistance R5, and the other end of the 5th resistance R5 is held with ground and is connected.

This partial circuit principle of work is same as described above, does not repeat them here.

The explanation of above embodiment just understands method of the present utility model and core concept thereof for helping.Should be understood that; for those skilled in the art; under the prerequisite not departing from the utility model principle, can also carry out some improvement and modification to the utility model, these improve and modify and also fall in the protection domain of the utility model claim.

To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the utility model.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein when not departing from spirit or scope of the present utility model, can realize in other embodiments.Therefore, the utility model can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (4)

1. a temperature protection circuit, is characterized in that, comprises the first chip U1, the first triode Q1, the first resistance R1, the second resistance R2, the 3rd resistance R3, the 4th resistance R4, the first temp-sensing element and the first blower module, wherein,

First pin of described first chip U1 is connected with one end of described 4th resistance R4, the other end of described 4th resistance R4 is connected with the base stage of described first triode Q1, the emitter of described first triode Q1 is held with ground and is connected, the collector of described first triode Q1 is connected with described first blower module, and described first blower module is also connected with the feeder ear of external power supply module;

One end of 8th pin of described first chip U1, one end of described 3rd resistance R3, described second resistance R2 is connected with the reference edge of external power supply module jointly; The other end of described 3rd resistance R3 is connected with second pin of described first temp-sensing element with described first chip U1, and described first temp-sensing element is also connected with ground end; The other end of described second resistance R2 is connected with the 3rd pin of described first chip U1 with one end of described first resistance R1, and the other end of described first resistance R1 is held with ground and is connected.

2. temperature protection circuit according to claim 1, is characterized in that, also comprises the second triode Q2, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the 8th resistance R8, the second temp-sensing element and the second blower module, wherein,

7th pin of described first chip U1 is connected with one end of described 8th resistance R8, the other end of described 8th resistance R8 is connected with the base stage of described second triode Q2, the emitter of described second triode Q2 is held with ground and is connected, the collector of described second triode Q2 is connected with described second blower module, and described second blower module is also connected with the feeder ear of external power supply module;

One end of described 7th resistance R7, one end of described 6th resistance R6 are connected with the reference edge of external power supply module jointly; The other end of described 7th resistance R7 is connected with the 6th pin of described second temp-sensing element with described first chip U1, and described second temp-sensing element is also connected with ground end; The other end of described 6th resistance R6 is connected with the 5th pin of described first chip U1 with one end of described 5th resistance R5, and the other end of described 5th resistance R5 is held with ground and is connected.

3. temperature protection circuit according to claim 1 and 2, is characterized in that, described first chip U1 adopts LM258.

4. temperature protection circuit according to claim 1, is characterized in that, described first temp-sensing element and described second temp-sensing element are NTC negative thermistor.