ELECTRONIC FREQUENCY RELAY Russian patent published in 2003 - IPC

FIELD: electrical engineering. SUBSTANCE: electronic frequency relay includes intermediate transformer and first threshold unit, selector of leading edge and selector of trailing edge connected in series which inputs are connected to output of first threshold unit 2, RS flip-flop which S input is connected to output of selector of leading edge, AND gate and counter connected in series, one-shot multivibrator and clock pulse generator which output is connected to second input of AND gate connected in series, arithmetic circuit which information input is connected to output of counter, which clock input is linked to input of zero setting of counter, to R input of RS flip-flop and to output of selector of trailing edge and which setting input is connected to output of one-shot multivibrator, OR gate and final control element connected in series, second and third threshold units which inputs are connected to output of arithmetic circuit and which outputs are connected correspondingly to first and second inputs of OR gate. EFFECT: simplified design and raised functional reliability of relay. 3 cl, 3 dwg