FREQUENCY DETECTOR FOR ROTOR OF ALTERNATING- CURRENT ELECTRIC MOTOR Russian patent published in 1997 - IPC

FIELD: electric engineering, in particular, high-precision electric systems with synch or rotating transformers. SUBSTANCE: sine and cosine outputs of electric motor are connected to differentiating filters and multipliers through phase-sensitive rectifiers. Digital inputs of multipliers are connected to output of reverse counter and their outputs to inertia filters. Outputs of phase-sensitive rectifiers are connected to inputs of comparators and outputs of filters are connected to inputs of other comparators. Outputs of comparators are connected to inputs of 3- AND gates which outputs are connected to control input of reverse counter through OR gate. Carry output of reverse counter and output of pulse oscillator are connected to inputs of 2-AND gate which output is connected to counting input of reverse counter. EFFECT: increased functional capabilities. 2 dwg