Due to the use of multiple power transistors and related transformers in the computer host, the power supply will have a heating problem after working for a period of time.therefore, the power transistors usually have to use cooling fan to dissipate heat in addition to installing cooling fins.

The existing computer is designed such that the cooling fan rotates continuously once the computer is turned on, so as to achieve the function of cooling.However, the cooling fan rotates continuously, resulting in many disadvantages. The continuous rotation of the cooling fan will produce continuous noise, which will directly affect the work of computer designers or operators.At the same time, the continuous rotation of the cooling fan will also waste energy.

What is more obvious is that when the computer is used for a long time, not only the necessary components of the computer generate serious heat, but also the motor of its heat dissipation fan will generate heat.Such vicious cycle will make the whole computer unable to operate normally at normal temperature, resulting in unexpected damage.

An automatic adjusting device capable of reducing computer fan noise is provided with a circuit board containing a fan control circuit so that the circuit board can be vertically inserted behind a power transistor heat sink on a power supply for a computer, a preset thermistor is arranged in front of the heat sink, and a gap distance is reserved; Therefore, when high temperature is generated, the thermistor can automatically adjust the voltage according to the change of temperature rise and fall, and can also cooperate with the middle variable resistor to make fine adjustment changes, and drive the fan to dissipate heat through primary and secondary amplification of the two electric transistors. When the temperature is low, the fan can be stopped or the rotating speed of the fan can be slowed down. The noise of the fan is greatly reduced, the service life of the fan is prolonged, and the electric energy is saved more effectively.