DIGITAL MODULATOR OF INDUCTION MOTOR FREQUENCY CHANGER Russian patent published in 1998 - IPC

FIELD: pulse engineering; control-system frequency changers. SUBSTANCE: digital modulator has square-pulse generator 1, counters 2 and 3, sign flip-flop 4, flip-flop 5, OR gates 6-9, inverter 10, AND gate 11, NAND gates 12-17, decoder 18, pulse shapers 19 and 20, adder 21, register 22, binary-sonary counter 23, limiting circuit 24, and reset circuit 25, output buses 26-31, input-signal bus 32, and sign bus 33. EFFECT: simplified design, provision for implementing $$$-switching control mechanism for frequency changer power transistors. 4 cl, 2 tbl