Patent ID: 8422182

Claim:
A solid-state relay system configured to be connected in series with an electrical load powered by alternative current, comprising: two series-mounted bidirectional field-effect transistors made of a wide band-gap material and configured to operate in a current limiting mode; a voltage detector to detect voltage across each of the transistors or across both transistors; an electromechanical relay mounted in series with the transistors; and a controller to switch off at least one transistor or the electromechanical relay when the detected voltage exceeds a threshold, wherein both transistors are of normally-on JFET type, gates of which are connected together, and wherein the system further comprises: two biasing resistors, each biasing resistor being respectively linked between the gate and the source of one of the power transistors; two control switches controlled by the controller, each control switch being respectively connected in parallel with one of the biasing resistors.