An improved energy-saving scheme for capacitor-run induction motor

Conventionally, the speed of a capacitor run single-phase induction motor is controlled by using an AC voltage controller (generally a triac) between the supply voltage and the motor. This letter proposes a new scheme, in which the triac is inserted in series with the main winding, while the motor auxiliary winding remains directly connected across the supply voltage. The experimental results indicate the superiority of the new method suggested in this letter.