Electronic control device for universal motor speed - has actual and required speeds applied as voltages to differential amplifier inputs

摘要

The high power motor speed control is achieved by balanced phase shifting control using a semiconductor control element. The device has a frequency pickup (2) generating a frequency (f) proportional to the motor speed (n), followed by a frequency into voltage convertor (22) whose output is connected to the non-inverting input (+) of a differential amplifier (4). It applies to the amplifier (4) input (+) an analogue DC voltage (U) proportional to the motor (12) speed. A continuously adjustable voltage generator (3) applies to the amplifier inverting input (-) the required speed (no) in the form of a DC voltage (Uo). The amplifier (4) output is connected to the phase shift control unit (5) which controls the phase of control signals for the semiconductor control unit (11).