Solid State Relay Transient Immunity

The Solid State Relay (SSR) is a solid-state replacement of the electro-mechanical relay, and is commonly used for general purpose switching of signals and low power AC/DC loads. This paper introduces two common phenomenons of the transient voltage effect on the SSR, as well as the various methods of transient rejection measurements. In addition, an over-voltage protection device is recommended to further shield the SSR from hazardous surge voltage.