FREQUENCY DIFFERENCE RELAY Russian patent published in 2003 - IPC

FIELD: electrical engineering. SUBSTANCE: frequency difference relay is used to adjust synchronized signal to input signal. Technical result of invention consists in expansion of functional potential as relay responds to relative mismatch of frequencies of input and synchronized signals and in increased accuracy since effect of short-time frequency errors of generator and high-frequency interference to its operation is eliminated. Frequency difference relay includes frequency meter of input signal, multiplier, two comparators, two final-control elements, meter of synchronized signal, algebraic adder, inverter, two AND gates, two pulse formers of leading edge. EFFECT: expanded functional potential. 1 cl, 2 dwg