Temp.-independent current limiter for three-phase supplies - compares phase-line signal evaluators output with remotely-set reference

摘要

The temperature-independent supply-current limiter, for 3-phase supplies, has a triple-input evaluator inductively coupled to the supply network phase lines and evaluating the phase and/or the shape and/or the root-mean-square and/or the mean value and/or the peak value of the signals in each phase line. The evaluator's single output is coupled over a delay line to a comparator where it is compared with an adjustable reference. The reference may be set by remote control and represents the limiter maximum output. Switching circuitry can be connected to the comparator output to pass the supply to several loads. The comparator output is fed back to the reference level unit to prevent the limiter automatically switching itself on again.