DIGITAL MODULATOR FOR CHANGING INDUCTION MOTOR FREQUENCY Russian patent published in 2003 - IPC

FIELD: pulse engineering; converter systems for induction motor control. SUBSTANCE: digital modulator designed for changing induction motor frequency has square pulse generator, counters, sign trigger, flip-flops, OR gates, inverter, AND gates, NAND gates, decoders, pulse shaper, adders, registers, binary-sextic counter, limiting circuit, clear circuit, output buses, input signal bus, and sign bus. Proposed digital modulator for changing frequency of induction motor enables generation of output signal which shapes set of three-phase quasi-sinusoidal variable- frequency and variable-amplitude voltages across induction motor phases when controlling three- phase power transistor bridge. EFFECT: enhanced reliability of motor frequency control. 1 cl, 5 dwg