SPEED CONTROL FOR INDUCTION MOTOR WITH VARIABLE VOLTAGE-FREQUENCY RATIO

摘要

A motor speed control for controlling the speed of an electric induction motor by modulating the amplitude and frequency of the driving voltage. When the load increases the speed control controls the speed so as to be relatively constant with respect to the frequency of the driving voltage. Preferably, the speed control controls the amplitude of the driving voltage in proportion to the square of the frequency.