CN202732417U - Stepless variable-speed temperature-control fan circuit - Google Patents

Abstract

The utility model provides a continuously variable speed temperature-controlled fan circuit, which includes a power supply, an MCU, a temperature acquisition circuit of discrete components, and an integral control circuit. The temperature acquisition point collects a temperature signal and feeds it back to the MCU. The pulse control signal is generated and output to the integral control circuit, and the integral control circuit converts the pulse control signal output by the MCU into a DC voltage signal and output to the fan power input interface. The infinitely variable speed temperature control fan circuit provided by the utility model adopts an accurate temperature acquisition circuit, and uses PWM control mode, so that the fan control can achieve real stepless speed change, low power consumption, and can be widely used in electronic products and household appliances. The temperature-controlled fan, because the circuit does not need a voltage regulator circuit, is only composed of ordinary discrete components, and the number is not large, so the cost is very low, and the overall circuit is simple and reliable.

Description

A stepless variable speed temperature control fan circuit

technical field

The utility model relates to an improved temperature-controlled fan circuit.

Background technique

With the rapid development of electronic technology, the heat dissipation of electronic components has become an important aspect affecting the performance of electronic equipment. For example, CPU, hard disk, etc. need continuous and effective heat dissipation to ensure their stable operation. Cooling fans are the best way to dissipate heat for many electronic products. However, the existing heat dissipation fans are deficient in temperature control, cannot balance heat dissipation efficiency and power consumption, the fan control accuracy is not high, and cannot intelligently solve the heat dissipation problem of the product, so the existing technology needs to be improved.

Utility model content

The purpose of the utility model is to provide a stepless variable speed temperature control fan circuit, aiming to solve the technical defects of low fan control accuracy and high power consumption in the prior art.

In order to achieve the above purpose, the continuously variable speed temperature control fan circuit provided by the utility model includes a power supply, an MCU and a temperature acquisition circuit of discrete components, and an integral control circuit. The temperature acquisition point collects a temperature signal and feeds it back to the MCU. The signal generates a pulse control signal and outputs it to the integral control circuit. The integral control circuit converts the pulse control signal output by the MCU into a DC voltage signal and outputs it to the fan power input interface.

Further, the MCU includes a power supply interface, a detection signal input interface, a voltage output interface and a ground terminal.

Further, the temperature acquisition circuit includes a thermistor, a diode, a triode, and a capacitor, the thermistor is connected between the base and the collector of the triode, the base of the triode is connected to the power supply through the thermistor, and the anode of the diode is connected to the triode The base of the capacitor and the negative pole are grounded through a resistor. The emitter of the triode is connected to the detection signal input interface of the MCU and grounded through the resistor at the same time. One end of the capacitor is connected to the detection signal input interface of the MCU and the emitter of the triode at the same time, and the other end is grounded.

Further, the integral control circuit includes a triode, a diode, a first capacitor, a second capacitor and an inductor, the collector of the triode is connected to the voltage output interface of the MCU through a resistor, the base is connected to the power supply through a resistor, and the anode of the diode is connected to the triode The collector, the negative pole is connected to the inductor, the resistor is connected in parallel to both ends of the diode, the inductor is connected between the negative pole of the diode and the fan voltage input interface, one end of the second capacitor is connected to the negative pole of the diode, the other end is grounded, and the emitter of the triode is grounded through the resistor , the first capacitor is connected between the voltage output interface of the MCU and the base of the triode.

The infinitely variable speed temperature control fan circuit provided by the utility model adopts an accurate temperature acquisition circuit, and uses PWM control mode, so that the fan control can achieve real stepless speed change, low power consumption, and can be widely used in electronic products and household appliances. The temperature-controlled fan, because the circuit does not need a voltage regulator circuit, is only composed of ordinary discrete components, and the number is not large, so the cost is very low, and the overall circuit is simple and reliable.

Description of drawings

Fig. 1 is a circuit diagram of a preferred embodiment of the infinitely variable speed temperature-controlled fan circuit of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

As shown in Figure 1, the continuously variable speed temperature-controlled fan circuit provided by the preferred embodiment of the present invention includes a temperature acquisition circuit, an integral control circuit, a power supply (POWER) and an MCU. The temperature acquisition circuit and integral control circuit are composed of discrete components.

The temperature acquisition circuit includes a thermistor RT101, a diode D102, a resistor R107, a triode Q102, a resistor R108 and a capacitor C103. The thermistor RT101 is connected between the base and the collector of the transistor Q102, the base of the transistor Q102 is connected to the power supply VCC through the thermistor RT101; the anode of the diode D102 is connected to the base of the transistor Q102, and the cathode is grounded through the resistor R107. The emitter of the triode Q102 is connected to the detection signal input interface of the MCU and grounded through the resistor R108 at the same time. One end of the capacitor C103 is connected to the detection signal input interface of the MCU and the emitter of the triode Q102, and the other end is grounded. When working, the thermistor RT101 changes its own impedance according to its thermal characteristics and the ambient temperature, thereby changing the impedance distribution of the circuit. As the impedance of the thermistor RT101 changes, the driving voltage of the base of the transistor Q102 also changes, and the emitter of the transistor Q102 is output to the MCU detection signal input interface. Output continuous PWM pulse control signals through the voltage output interface.

The integral control circuit includes a resistor R105, a capacitor C101, a transistor Q101, a resistor R106, a resistor R104, a diode D101, a resistor R103, a capacitor C102 and an inductor L101. The base of the transistor Q101 is connected to the voltage output interface of the MCU through the resistor R105, and the collector is connected to the power supply VDD through the resistor R103. The anode of the diode D101 is connected to the collector of the transistor Q101, and the cathode is connected to the inductor L101. Resistor R104 is connected in parallel with both ends of diode D101. The inductor L101 is connected between the cathode of the diode D101 and the fan (FAN) voltage input port VD. One end of the capacitor C102 is connected to the cathode of the diode D101, and the other end is grounded. The emitter of the transistor Q101 is grounded through the resistor R106. The capacitor C101 is connected between the voltage output interface of the MCU and the base of the transistor Q101, and a resistor R105 is connected in parallel with both ends thereof. When working, the above integral control circuit converts the PWM signal output by the voltage output interface of the MCU into a DC voltage signal output, and after filtering by L101, it is sent to the fan input interface, so that the fan can adjust the speed according to the voltage level. Start and stop the fan according to the actual temperature. At the same time, the fan feeds back the speed information output to the MCU detection signal input interface through its own detection port, and the MCU can display the fan speed information on the screen, so that the user can understand and grasp the fan speed in real time.

The MCU includes a power supply interface, a detection signal input interface, a voltage output interface and a ground terminal, and the power supply interface of the MCU is connected to the power supply VCC through a resistor R101 and a resistor R02. When working, the MCU converts the temperature information into a controllable pulse waveform by detecting the input signal, and at the same time displays the temperature and rotational speed information through the user menu. The user menu not only has real-time temperature and speed information display, but also can perform operations such as fan on/off, gear shifting, automatic/constant speed, and temperature setting, which is very simple and convenient to use.

The infinitely variable speed temperature control fan circuit provided by the circuit of the utility model is a software and hardware automatic detection and closed-loop control system. The design of the whole system is reasonable and reliable, the temperature acquisition is real-time and accurate, the control is continuous and reliable, the temperature control point can be set arbitrarily, and the fan switch state can be arbitrarily The speed of the fan can be adjusted at will, and the speed can reach stepless speed change at will. When the fan is abnormal, it will automatically alarm and display.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. All modifications, equivalent replacements and improvements made within the spirit and principles of the utility model shall be included in the protection scope of the claims of the utility model.

Claims (4)

1. stepless change temperature-controlled fan circuit, it comprises power supply and MCU, it is characterized in that further comprising temperature collection circuit, the integral control circuit of discrete component, described temperature acquisition point road collecting temperature signal also feeds back to MCU, MCU produces pulse control signal and exports to integral control circuit according to temperature signal, and the pulse control signal that described integral control circuit is exported MCU is transformed to d. c. voltage signal and exports to delivers to the fan power supply input interface.

2. stepless change temperature-controlled fan circuit according to claim 1 is characterized in that described MCU

Comprise power interface, testing signal input interface, Voltage-output interface and grounding end.

3. stepless change temperature-controlled fan circuit according to claim 3, it is characterized in that, described temperature collection circuit comprises thermistor (RT101), diode (D102), triode (Q102), electric capacity (C103), thermistor (RT101) is connected between the base stage and collector electrode of triode (Q102), the base stage of triode (Q102) connects power supply by thermistor (RT101), the base stage of the anodal connecting triode (Q102) of diode (D102), negative pole is by resistance (R107) ground connection, the emitter of triode (Q102) connects the testing signal input interface of MCU and passes through simultaneously resistance (R108) ground connection, one end of electric capacity (C103) connects the testing signal input interface of MCU and the emitter of triode (Q102), the other end ground connection simultaneously.

4. stepless change temperature-controlled fan circuit according to claim 2, it is characterized in that, described integral control circuit comprises triode (Q101), diode (D101), the first electric capacity (C101), the second electric capacity (C102) and inductance (L101), the base stage of triode (Q101) is connected to the Voltage-output interface of MCU by resistance (R105), collector electrode is connected to power supply by resistance (R103), the collector electrode of the anodal connecting triode (Q101) of diode (D101), negative pole connects inductance (L101), resistance (R104) is connected in parallel on the two ends of diode (D101), inductance (L101) is connected between the negative pole and fan voltage input interface (VD) of diode (D101), the second electric capacity (C102) end connects the negative pole of diode (D101), the other end ground connection, the emitter of triode (Q101) is by resistance (R106) ground connection, and the first electric capacity (C101) is connected between the base stage of the Voltage-output interface of MCU and triode (Q101).

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