Solid-state load protection system having electronic simulation of motor heating

Abstract From the Canadian patent

A solid-state load protection system having electronic simulation of motor heating characteristics. A current sensing function is utilizes so as to produce an output signal which is related to the current in an electrical circuit. Attached to the current sensing function is an inverse time delay circuit and has a signal path for charging and discharging a capacitor. The voltage across the capacitor is related to the thermal state of the load. Depending upon the voltage across the capacitor the, inverse time delay circuit which is essentially an overcurrent and timing function which is monitoring the voltage will initiate either a time-out or trip sequence or a reset sequence. The time …