What is Electric fan | how electric fan works?
Electric fans, which everyone of us has seen at homes is need of summers when the atmospheric temperature goes above the comfort level of human body.
Electric fan when rorates, blows away air around it towards the corners of room and thus speeds up the evaporation process resulting in the cooling of human body and room.
Components of electric fan:
Capacitor: Start capacitor is used in electric fans, As we know capacitors stores energy and this stored energy is used to rotate the fan from rest state. This capacitor increases electric fan motor torque and allows motor to rotate rapidly. This capacitor stays in to circuit until only the electric fan reaches predetermined speed, This predetermined speed is usually the 75% of the full speed of fan and when fan reaches the predetermined speed this capacitor is taken out of the circuit and will again be incorporated into circuit when fan comes at rest state. Learn more about Capacitors here.
Axle: Axle or Shaft is the metallic rod mostly made up of mild steel. Axle is connected from ceiling to fan housing. It stays at rest motion while bearings supporting the housing over it rotates.It also has arrangement for transfer of current to the stator windings.
Bearings: Ball bearings are used in the electric fan. As shown in the picture, 2 bearings which are link between housing and axle gives the rotary motion to the housing.
Stator: Stator winding is simply the stationary winding in the electric fan motor winding. Stator winding means thousands of turns of conducting wire on any non conducting structure like a coil. This winding has very low resistance. Main purpose of stator winding is to convert electric current into magnetic field.
Rotar: Rotor in the electric motor is the permanent magnetic in the shape of half circles. Usually 2 pcs of Magnets are used in Electric fan but this can change to 3 pcs or to single pc depending upon size and capacity of electric fan.
Housing: Housing is the outer part of the electric fan which carries stator, rotor and drive shaft bearing assembly on inside and baldes on outer sides.
Blades: Blades or wings are the hanging part bolted on the outer area of housing. Three blades are mostly used and their length and the angle of air throw depends upon the size and capacity of electric motor.
Working principle of Electric fan:
Electric fan works on the principle of conversion of electric energy into mechanical energy and in this case mechanical energy is the rotary motion. When AC is supplied to electric fan it first reaches the capacitor and Capacitor delivers high energy to the stator windings. When stator winding energizes, it develops the rotating magnetic field and which forces the rotor to rotate in the direction of rotating magnetic field.
In this way electrical energy is converted into mechanical energy which causes the rotor and housing to spin and the blades attached to the housing throws away the air nearby it while creating cooling effect.