RMS CALCULATION CIRCUIT FOR DIGITAL CIRCUIT INTERRUPTERS

摘要

RMS CALCULATION CIRCUIT FOR DIGITAL CIRCUIT INTERRUPTERS The root mean square value of sensed current within a protected circuit is used to determine the occurrence of an overcurrent condition. A frequency multiplying circuit produces a pulse stream having a frequency proportional to the square of the amplitude of an analog signal representation of the circuit current. A root mean square value over a prescribed interval is developed from the squared current value. The RMS value is processed within an integrated circuit trip unit to determine an overcurrent condition and to operate a pair of separable contacts to interrupt the circuit current.