| 摘要 |
A waveform synthesizer for generating single or poly-phase waveforms of selected wave shape and frequency for driving AC machinery including, for example, single or poly-phase induction, synchronous or other type motors or the like, includes a plurality of controllable power-switching device pairs for selectively switching power from an oppositely poled DC source to the corresponding power utilizing circuits of the driven device. The swithching device pairs are controlled to provide switched pulses of selected widths, spacings, and repetition rates to generate the desired current waveform. The power switching device pairs are selectively switched by a control circuit that includes a microprocessor controlled memory that is divided into p addressable pages with each page including s sequentially accessible memory locations containing the switching device pairs control information necessary to synthesize the desired waveform. The microprocessor is adapted to select one of the p available pages in response to pre-stored instructions, user input information, or condition-responsive transducer outputs and, after selecting the desired page, to control a pre-settable address counter to sequentially access the s memory locations of the selected page at a selected access rate and to gate the accessed switching information to the power switching device pairs to thereby synthisize the desired waveform.
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