CN208316283U - A kind of overheat protector and fan control circuitry of Switching Power Supply - Google Patents

Abstract

The utility model provides the overheat protector and fan control circuitry of a kind of Switching Power Supply, is mainly made of fan F1, resistance R1~6, thermistor R7, electrolytic capacitor C1, C2, capacitor C3, diode D1, D2, three-terminal voltage-stabilizing pipe ZD1 and triode Q1；One end of R1, the anode of C1, the emitter-base bandgap grading of Q1, one end of R6 and one end of R7 collectively form power end；One end of the other end of R7, the cathode of D1 and R2 is conllinear；The other end of R2, the control terminal of ZD1, one end of C3, one end of R3, R4 are conllinear；The other end of R3 is electrically connected with the cathode of D2；The anode of D2, the collector of Q1, the power end of the anode of C2 and fan F1 are conllinear.The utility model, which controls starting fan work when Switching Power Supply internal temperature is more than 55 degree, reduces noise to save electric energy；When internal temperature is more than 105 degree, power supply is turned off the switch to prevent because of the excessively high scaling loss of internal temperature.

Description

A kind of overheat protector and fan control circuitry of Switching Power Supply

Technical field

The utility model relates to switch power technology fields, and in particular to a kind of overheat protector of Switching Power Supply and fan control Circuit processed.

Background technique

Switching Power Supply is widely used in fields such as Industry Control, LED displays.Switching Power Supply usually by shell and is mounted on Circuit device in shell is constituted.Since Switching Power Supply is equipped with a large amount of circuit devcie, thus its in the shell of small volume Heat dissipation problem when work is the technical issues of must be taken into consideration.Currently, common Switching Power Supply heat dissipation relies primarily on built-in wind Fan, fan are connected to the output end work once electrified on the output end of Switching Power Supply from Switching Power Supply, the problem is that, it is such Under mode, the work as long as Switching Power Supply is switched on, whether is it working always for unloaded or light condition, fan, on the one hand It is unfavorable for saving electric energy, and influences fan life；Another aspect fan rotates always the influence of noise ambient enviroment of generation.Together When, Switching Power Supply common at present does not consider overheat protector problem usually, so that Switching Power Supply exists in use because of mistake The possibility of hot scaling loss.

Utility model content

The purpose of this utility model is: aiming at the problems existing in the prior art, the excess temperature for providing a kind of Switching Power Supply is protected Shield and fan control circuitry only just connect fan work when temperature reaches setting value in Switching Power Supply when the circuit works, So as to save electric energy and extend fan life, at the same when temperature is excessively high in Switching Power Supply reach setting value when the circuitry cuts open The output in powered-down source, to prevent Switching Power Supply because overheating scaling loss.

The technical solution of the utility model is: the overheat protector and fan control circuitry of the Switching Power Supply of the utility model, There is power end and ground terminal including fan F1, said fans F1；It is characterized by: this circuit further include resistance R1, R2, R3, R4, R5, R6, thermistor R7, electrolytic capacitor C1, C2, capacitor C3, diode D1, D2, three-terminal voltage-stabilizing pipe ZD1 and triode Q1；

One end, the anode of electrolytic capacitor C1, the emitter-base bandgap grading of triode Q1, one end of resistance R6 and the temperature-sensitive of above-mentioned resistance R1 One end of resistance R7 forms a public point because conllinear, the power end of the public point structure cost circuits；Thermistor R7 The other end, the cathode of diode D1 and one end of resistance R2 form a public point due to conllinear, the public point structure The excess temperature control terminal of cost circuits；The overheat protector signal output end of the positive structure cost circuits of diode D1；Resistance R2's is another One end, the control terminal of three-terminal voltage-stabilizing pipe ZD1, one end of capacitor C3, one end of resistance R3 and resistance R4 one end due to conllinear A public point is formed, the fan control end of the public point structure cost circuits；The other end of resistance R3 is with diode D2's Cathode electrical connection；The anode of diode D2, the collector of triode Q1, the positive of electrolytic capacitor C2 form a public affairs because conllinear Endpoint altogether, the fan power supply output end of the public point structure cost circuits；The output end of three-terminal voltage-stabilizing pipe ZD1 and the one of resistance R5 End electrical connection；The base stage of the other end of resistance R5, the other end of resistance R6 and triode Q1 is conllinear；The other end of resistance R1, The cathode of electrolytic capacitor C1, the cathode of electrolytic capacitor C2, the input terminal of three-terminal voltage-stabilizing pipe ZD1, capacitor C3 the other end and electricity The other end of resistance R4 is grounded；

In use, the power end of said fans F1 is electrically connected with the fan power supply output end of this circuit；The ground connection of fan F1 End ground connection；The output head anode of the power supply termination Switching Power Supply of this circuit；The overheat protector signal output end and switch of this circuit The driving chip signal of power supply is electrically connected.

Further embodiment is: the model AZ431 of above-mentioned three-terminal voltage-stabilizing pipe ZD1；The model of thermistor R7 TTC3A502G39H2EY；The model 2SA562 of triode Q1.

The utility model has the effect of positive: the overheat protector of the Switching Power Supply of the utility model and fan control electricity Road, by making the overheat protector of Switching Power Supply and the design of fan control integrated circuit and parts selection and parameter selection It obtains fan and only just starts work when Switching Power Supply internal temperature is more than 55 degrees Celsius, temperature is lower than 55 degrees Celsius in Switching Power Supply When fan do not work, to save electric energy, reduce noise and the service life of fan can be extended；Meanwhile inside Switching Power Supply When temperature is more than 105 degrees Celsius, then makes Switching Power Supply stop working cooling, prevent Switching Power Supply from crossing high fever because of internal temperature Damage, protective efficient switch power supply and its application apparatus using safe.

Detailed description of the invention

Fig. 1 is the circuit structure diagram of the utility model.

Specific embodiment

Utility model will be further described in detail below with reference to the attached drawings and specific embodiments.

(embodiment 1)

See Fig. 1, the overheat protector and fan control circuitry of the Switching Power Supply of the present embodiment, mainly by fan F1, resistance R1, R2, R3, R4, R5, R6, thermistor R7, electrolytic capacitor C1, C2, capacitor C3, diode D1, D2, three-terminal voltage-stabilizing pipe ZD1, Triode Q1 composition.Fan F1 has power end and ground terminal.

One end of resistance R1, the anode of electrolytic capacitor C1, the emitter-base bandgap grading of triode Q1, one end of resistance R6 and thermistor One end of R7 forms a public point because conllinear, the power end of the public point structure cost circuits；Thermistor R7's is another One end of one end, the cathode of diode D1 and resistance R2 forms a public point because conllinear, which constitutes this The excess temperature control terminal of circuit；The overheat protector signal output end of the positive structure cost circuits of diode D1；The other end of resistance R2, The control terminal of three-terminal voltage-stabilizing pipe ZD1, one end of capacitor C3, one end of R3 and resistance R4 one end form a public affairs because conllinear Endpoint altogether, the fan control end of the public point structure cost circuits；The other end of resistance R3 is electrically connected with the cathode of diode D2； The anode of diode D2, the collector of triode Q1, the positive of electrolytic capacitor C2 form a public point because conllinear, the public affairs The fan power supply output end of endpoint structure cost circuits altogether；The output end of three-terminal voltage-stabilizing pipe ZD1 is electrically connected with one end of resistance R5；Electricity The base stage for hindering the other end of R5, the other end of resistance R6 and triode Q1 is conllinear；The other end of resistance R1, electrolytic capacitor C1 Cathode, the cathode of electrolytic capacitor C2, the input terminal of three-terminal voltage-stabilizing pipe ZD1, the other end of capacitor C3 and resistance R4 the other end It is grounded.

In use, the power end of fan F1 is electrically connected with the fan power supply output end of this circuit；The ground connection of fan F1 terminates Ground；The output head anode (usually DC12.7V) of the power supply termination Switching Power Supply of this circuit；The overheat protector signal of this circuit is defeated Outlet is electrically connected with the driving chip signal of Switching Power Supply；Other circuits and device of Switching Power Supply in addition to this circuit are existing There is technology, is not detailed.

In the present embodiment, the model of three-terminal voltage-stabilizing pipe ZD1 preferably uses AZ431；The model of thermistor R7 preferably uses TTC3A502G39H2EY；The model of triode Q1 preferably uses 2SA562.

The overheat protector and fan control circuitry of the Switching Power Supply of the present embodiment, working principle are summarized as follows:

When power supply cold works, 12.7V voltage passes through thermistor R7, resistance R2, resistance R4 electric resistance partial pressure to this circuit Fan control end (control terminal of three-terminal voltage-stabilizing pipe ZD1), as Switching Power Supply works, Switching Power Supply internal temperature increase, heat The resistance value of quick resistance R7 linearly becomes smaller therewith, so that the voltage of the control terminal of three-terminal voltage-stabilizing pipe ZD1 constantly increases, when three ends When the control terminal voltage of voltage-stabiliser tube ZD1 is raised to 2.5V or more, three-terminal voltage-stabilizing pipe ZD1 conducting, so that triode Q1 is connected, 12.7V power supply gives fan F1 power supply by triode Q1, and fan F1 starts running heat dissipation.In the present embodiment, preferably when switch electricity Starting fan F1 work when temperature is more than 55 degrees Celsius in source.Fan F1 not work when temperature is lower than 55 degrees Celsius in Switching Power Supply Make, to save electric energy, reduce noise and the service life of fan F1 can be extended.Meanwhile working long hours with Switching Power Supply, it opens Powered-down source internal temperature further increases, and the resistance value of thermistor R7RTH3 linearly becomes smaller, when the excess temperature control terminal electricity of this circuit Pressure reach 11V(correspond to Switching Power Supply internal temperature be 105 degrees Celsius) more than when, diode D1 reverse-conducting, output excess temperature guarantor Protecting signal to the driving chip of Switching Power Supply makes it stop working, so that Switching Power Supply be made to stop working cooling, prevents switch electric Source is because of the excessively high scaling loss of internal temperature.

Above embodiments are the explanations to specific embodiment of the present utility model, rather than limitations of the present invention, Person skilled in the relevant technique can also make various changes in the case where not departing from the spirit and scope of the utility model It changes and changes and obtain corresponding equivalent technical solution, therefore should to be included into this practical new for all equivalent technical solutions The scope of patent protection of type.

Claims (2)

1. the overheat protector and fan control circuitry of a kind of Switching Power Supply, including fan F1, the fan F1 have power end and Ground terminal；It is characterized by: the circuit further include resistance R1, R2, R3, R4, R5, R6, thermistor R7, electrolytic capacitor C1, C2, capacitor C3, diode D1, D2, three-terminal voltage-stabilizing pipe ZD1 and triode Q1；

One end, the anode of electrolytic capacitor C1, the emitter-base bandgap grading of triode Q1, one end of resistance R6 and the thermistor of the resistance R1 One end of R7 forms a public point because conllinear, which constitutes the power end of the circuit；Thermistor R7's One end of the other end, the cathode of diode D1 and resistance R2 forms a public point because conllinear, which is constituted The excess temperature control terminal of the circuit；The anode of diode D1 constitutes the overheat protector signal output end of the circuit；Resistance R2's The other end, the control terminal of three-terminal voltage-stabilizing pipe ZD1, one end of capacitor C3, one end of resistance R3 and resistance R4 one end because conllinear And a public point is formed, which constitutes the fan control end of the circuit；The other end and diode of resistance R3 The cathode of D2 is electrically connected；The anode of diode D2, the collector of triode Q1, the positive of electrolytic capacitor C2 form one because conllinear A public point, the public point constitute the fan power supply output end of the circuit；The output end and resistance of three-terminal voltage-stabilizing pipe ZD1 One end of R5 is electrically connected；The base stage of the other end of resistance R5, the other end of resistance R6 and triode Q1 is conllinear；Resistance R1's is another One end, the cathode of electrolytic capacitor C1, the cathode of electrolytic capacitor C2, the input terminal of three-terminal voltage-stabilizing pipe ZD1, capacitor C3 the other end with And the other end of resistance R4 is grounded；

In use, the power end of the fan F1 is electrically connected with the fan power supply output end of the circuit；The ground terminal of fan F1 Ground connection；The output head anode of the power supply termination Switching Power Supply of the circuit；The overheat protector signal output end of the circuit with open The driving chip signal in powered-down source is electrically connected.

2. the overheat protector and fan control circuitry of Switching Power Supply according to claim 1, it is characterised in that: three end The model AZ431 of voltage-stabiliser tube ZD1；The model TTC3A502G39H2EY of thermistor R7；The model of triode Q1 2SA562。