PHASE-DIFFERENCE MONITOR FOR RELAY PROTECTION Russian patent published in 2000 - IPC

FIELD: relay protection, applicable for protection of high-voltage electrical installations. SUBSTANCE: the device additionally uses: units of input circuits, automatic level control, "memory" elements, differential shift elements and comparators-limiters linked with one another in succession in the mentioned order; it also uses: 2NOR gate, frequency divider, clock pulse generator, digital-to- analog converter, successive approximation register, attenuator, comparator. EFFECT: expanded functional abilities, enhanced speed of response, sensitivity and noise immunity. 3 dwg