FREQUENCY RELAY Russian patent published in 2003 - IPC

FIELD: electrical engineering. SUBSTANCE: relay designed to check for commercial frequency deviation from rated value and to perform both overfrequency and underfrequency relay functions at a time has isolating transformer, frequency filter, frequency-dependent component, four comparators, two pulse shapers, two AND gates, two pulse counters, two nonrecursive filters, final element, delay circuit, monostable multivibrator, and clock generator. EFFECT: enlarged functional capabilities. 1 cl, 6 dwg