FREQUENCY RELAY Russian patent published in 2003 - IPC

FIELD: electrical engineering. SUBSTANCE: relay that functions to check for deviation of commercial frequency from rated value and to adjust it by raising or reducing this frequency has series-connected isolating transformer, frequency filter, voltage divider, first threshold unit, differentiating member, first pulse shaper, and first AND gate; series-connected frequency-dependent phase-shifting unit and second threshold unit; second AND gate; series-connected reversing counter, memory register, double-threshold comparator, and final element; series-connected monostable multivibrator whose output is connected to input of memory register zero-setting input, and clock generator; series-connected second pulse shaper, delay circuit, and first OR gate, as well as commercial-frequency reference-signal digital code shaper whose output is connected to commercial-frequency reference-signal setting input for first pulse shaper. EFFECT: enlarged functional capabilities. 2 cl, 2 dwg