CURRENT RELAY Russian patent published in 2005 - IPC

FIELD: electrical engineering; electronic relays responding to increment in current, for instance reverse-sequence current.

SUBSTANCE: proposed relay has intervening current transformer whose input functions as information input of current relay; rectifier; final element; first, second, and third threshold units; first and second AND gates; reversing counter; monostable multivibrator; clock generator; and frequency sensor; monostable multivibrator input functions as trigger input of current relay; newly introduced in device are algebraic adder whose output is connected to first threshold unit input; delay unit whose input is connected to addition input of algebraic adder and to rectifier output and output, to algebraic adder subtraction input; short-pulse shaper; and third AND gate whose direct input is connected to second short-pulse shaper and to HIGHER output of first threshold unit, inverse input, to short-pulse shaper output; output of third AND gate is connected to second direct input of second AND gate.

EFFECT: enhanced noise immunity.

1 cl, 4 dwg