摘要 |
A three-phase A-C speed controller for small integral and fractional horsepower motors includes a phase locked loop comprised principally of a phase comparator and voltage controlled oscillator to generate phase delayed trigger signals for energizing the windings of a three-phase A-C motor. A pair of shift registers are cascaded with a flip-flop to generate the 60 DEG phase delay between phases as is necessary in a three-phase system.
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