Silicon gate-controlled AC switch and its applications

A new silicon switch, called Triac, having three terminals and able to control alternating current, is described. It is an avalanche device controlling load current flow in both directions in response to a gate signal. Some of the properties of the Triac are described, and circuits such as on-off and gradual controls are shown for its control. Applications for the Triac include the control of electric heaters, and of incandescent and fluorescent lights.