Overcurrent Detector for Wire Chamber High Voltage Supplies

A high-potential isolated circuit for remotely measuring, monitoring, and crowbarring high-voltage power supplies at a variable preset current threshold level is described. It is presently being used in a high-energy physics experiment utilizing proportional chambers which require self-destruct protection from high-current discharges. An absolute current threshold of one microampere has been achieved. The circuit is not damaged by momentary current overloads of ten amperes or less.