Abstract: An electronic contactor controller circuit able to handle high currents and voltages includes an integrated circuit power circuit switch which provides a measuring output signal representative of the load current to an operational amplifier current to voltage convertor. The output voltage of the operational amplifier is provided to an input of a comparator, and at least one reference voltage, from reference voltage generating circuitry, is provided to the other input of the comparator. The comparator outputs a signal to control a timer circuit, which in turn controls the current switch.