System for controlling the rotational speed of an alternating voltage induction motor with the correction of Mosfet transistor switching

The object of the invention is a control system of an induction alternating-current motor rotational speed with correction of turning on of a MOSFET transistor which is intended to reduce electromagnetic interference that occurs during operation of the induction motor in radio receivers and other equipment when they are used. The control system of an induction alternating-current motor rotational speed with correction of turning on of a MOSFET transistor according to the invention consists of the following components connected into a circuit: a signal shaping circuit ( 1 ) to form a 50 Hz signal derived from the mains voltage, a controlling microprocessor ( 2 ), a photocoupler ( 3 ), a MOSFET transistor ( 4 ), a capacitor C ( 5 ), a temperature sensor ( 6 ), a motor ( 7 ), a relay ( 8 ), a bridge-rectifier ( 9 ) with diodes D4, D5, D6, and D7, a power supply ( 10 ) with resistors R1, R6, Zener diode D2, diode D3, capacitor C1, a set ( 11 ) of R2 and R3 resistors to establish the operating point of the MOSFET transistor ( 4 ), a capacitor C3 ( 12 ), a switching transistor T1 ( 13 ), and resistors R4 and R5 ( 14 ).