SOLID STATE RELAY ARRANGEMENT

A Triac connected in series circuit with an alternating current electrical load has its gate electrode connected to a secondary winding of a transformer the primary winding of which is connected to a source of alternating electrical current; when a related control switch is closed the primary winding causes an induced voltage in the secondary winding which is out of electrical phase with the source; the induced voltage is then sufficient to develop a triggering current, at least equal to the gate threshold current, which is applied to the gate electrode as the potential across the Triac swings through a zero potential.