CONTACTLESS SWITCH OF A STARTER WINDING IN SINGLE-PHASE ELECTRIC MOTOR

摘要

The device can be used in asynchronous single-phase electric motors for mechanical handling mechanisms. When a single-phase electric motor is started, the start-up winding and a start-up capacitor are switched on in series to the supply mains voltage, and any changes of the voltage in the start-up winding of the electric motor is monitored by means of a differential amplifier, and which voltages increases with the increase of the revolutions speed and when a preset threshold value is reached the supply voltage to the winding and the capacitor is cut off. This is effected by making use of a TRIAC VD2 in the main circuit, and its control is effected by a glavanically separation element TRIAC Optron DA1 which cuts off when the momentum value of the start-up current gets acros OV which is of significant imprtance for reducing the swtiching off of interferences to the supply mains. (11) 95/!