Phase angle control circuit for motor - has triac with diac, RC-circuit and potentiometer allowing long supply leads

摘要

The phase-angle control circuit is used for an electric motor. It has a triac between the rotor and field winding. An RC circuit is connected in parallel with the triac and a diac connects the junction between capacitor and resistor to the gate of the triac. The resistor (R) is connected via a potentiometer (P) between the current source (Q) and the field winding (F2) to the supply lead. A capacitor (C2) is connected in parallel with the potentiometer. The advantage lies in being able to use long supply leads.