Why are some fans blowing out simulated natural wind?

Before the invention of air-conditioning, fans were indispensable electrical appliances to prevent heat and cool down on summer days. At that time, the fan structure was relatively simple, installing four leaf-shaped rotors on the axis of an electric motor, the electric motor rotating, pulling the rotors to spin, a blow immediately blew out. The amount of wind can not be changed, unlike the strong, weak natural wind. Therefore, if the fan runs for a long time, people will feel uncomfortable.

Although later different types of fans appeared with varying speeds, the wind blowing out with different strengths and weaknesses, this fan’s amount of wind changed the speed only a few fixed steps and had to use your hands to turn on, can not be automatically changed, greatly different from the unique constant changing the strong feeling of the gentle natural wind blowing through the body.

For the fan to blow out simulated natural wind, install a self-igniting electronic oscillator in the fan due to an integrated circuit or a crystal ball. The periodic fluctuating current signal at the output of the electronic oscillator will control the electric motor’s voltage, causing the voltage applied to the electric motor as well. There is a cycle accordingly, thereby making the amount of wind in the fan blowing out also a periodic change from strong to weak, from weak to strong. This ever-changing wind blows on the body, indeed a bit similar to the natural wind.