FREQUENCY OR PHASE RELAY Russian patent published in 1996 - IPC

FIELD: power engineering; automatic control of power systems. SUBSTANCE: frequency or phase relay has not only internal read-only memory but also external user-programmed ROM for setting desired values. Mode of operation of steps is selected by means of switches, each being controllable. Serial code is transmitted from ROM to setting register, from analog-to-digital converter register and flip-flop state register to external circuits at lower frequency obtained by means of frequency divider whose input is connected to master oscillator output. Input of analog-to-digital converter counter may be connected by means of controllable switch to master oscillator output directly or through frequency divider. Minimum period of controlled frequency is determined by time of comparison of all settings with measured value of period or phase (1360 mcs). Step operating time is reduced to four periods. Provision is made for serviceability check of external circuits. High- and low-frequency simulating circuits are incorporated to check system for reliable functioning. EFFECT: facilitated setting procedure, enlarged functional capabilities of relay, reduced operating time. 1 dwg