The 53225 is a military SPST solid-state relay. This light-weight device is mechanically resistant and electrically immune to contact-related problems inherent in mechanical relays. An I2t current let-through curve assures power supply, relay, and load protection from thermal stress yet provides large momentary currents to charge capacitive loads or start inductive loads. Any current versus time above the I2t curve initiates a trip condition and a status output is generated. Effective isolation of 1000 VRMS is provided from all inputs, case and outputs through magnetic coupling. Magnetic coupling contributes to very low control power, repeatable turn-on/turn-off times, and no output stage currents to provide status signals.