AC ELECTRIC DRIVE Russian patent published in 1996 - IPC

FIELD: control systems of machines, machine-tools, automated industrial and domestic sewing machines. SUBSTANCE: ac drive has uncontrollable rectifier 12 and is provided with carrier-frequency generator whose output is connected to third input of third three-input adder 19, two flip-flops 13, 20, inverter 14, two AND gates 15, 16, and two controlled switches 8, 9 with four inputs and three outputs; first, second, and third inputs of first controlled switch 8 are connected to three like-polarity outputs of scaling-distributing device 7 whose fourth, fifth, and sixth outputs are coupled with first, second, and third inputs of second controlled switch 9; input of first flip-flop 13 is connected to output of master oscillator 17 and its output is connected to second input of second AND gate 16 and through inverter 14, to first input of first AND gate 15 whose second input is connected to output of second flip-flop 20 whose input is connected to output of third adder 19 and output, to first input of second AND gate 16. Output of each AND gate is coupled with fourth input of like-polarity controlled switch 8 (9). First, second, and third outputs of first controlled switch 8 are connected with like-polarity control inputs of self-contained inverter 10 whose fourth, fifth, and sixth control inputs are connected to first, second, and third outputs of second controlled switch 9. EFFECT: improved design. 2 dwg