Specifically, I want two questions answered:1.How does a single-phase permanent split capacitor AC induction motor work? (I know it involves the phase difference between a capacitor's current and voltage, but I need some more detail).2. All the fans in my house with this type of motor have 3 speeds. How do they achieve these three speeds? I've taken apart the motors and found 4 pairs of coils (i.e. 8 coils in total)?
Re added details: If there is no resistor inside, there must be voltage taps on the windings. I think that is the most common arrangement for a lot of types of fans.
yes,it is a single phase induction motor. its speed is controlled by regulators which have different resistances in them. there are 4 or 5 resistances in the increasing order kept inside the regulator box. when we turn the speed ,we change the resistances.when the fan is off,there is no current flowing hence it does not work. when we change the speed to 1, the resistance is internally set to the highest of all resistances. gradually when u move on speed to 2,3,4.. the resistance value decreases. at full-speed the fan is at no resistance. that means it consumes all the current flowing.As resistance reduces the current flow, so is the power affected thereby the speed of the fan is controlled. internally when u change the speed, the connections are accordingly changed.
Question 1: you can get this information from any text book with pages of explanation. Capacitor...current is 90 degree advancing than voltage. Coil....is opposite than capacitor. Question 2: It just series with two more chokes. Adding one choke,lesser current go to the motor (choke ressist AC current).....middle speed. Adding two chokes .......slow speed. No choke is added....full speed or High.
