Solid State Relay (SSR) Circuit using Two MOSFETs SSR or Solid state relays are high power electrical switches that work without involving mechanical contacts, instead they use just a couple of solid state semiconductors like MOSFETs for switching an electrical load, smoothly, and with high efficiency. SSRs can be used for operating high power loads, through a small input trigger voltage with negligible current. These devices can be used for operating high power AC loads as well as DC loads. Sol