Drive apparatus

摘要

An object (12) is moved by a motor (16) at a command speed which is a desired function of time. The current applied to the motor (16) is controlled in accordance with the phase difference between a periodic digital command speed signal and a periodic digital actual speed feedback signal. The two digital signals are applied in combination as an address input to a memory (67) which stores in the addresses thereof digital drive signals having magnitudes which are predetermined in accordance with the phase difference. The current applied to the motor (16) is proportional to the magnitude of the addressed drive signal.