| 摘要 |
PURPOSE:To transform an input/output waveform to a sine wave up to the lowest frequency area, by thinning out pulse pattern applied to the semiconductor element of a power converter under specified conditions. CONSTITUTION:So far as a power converter is concerned, transistors (hereinafter, Tr) 31-36 composing the main switching element of a current type converter section 3, and the Trs 51-56 of a current type inverter section 5 are controlled by a control circuit, and the induction motor 7 of a load is driven. The control circuit is composed of a DC current detecting section 8, a comparator 9, and one-chip micro-computers 10, 11 for feeding pulse pattern (control signal) to the Trs 31-56. the micro-computer 10(11) is composed of a ROM 103, a RAM 104, an ALU 105, the registers of a phenomenon setting register 107 and the like, an associative memory 110, a timer 111, and the like. When a pulse width is smaller than the limit value, then function thinning out pulse so that it may form a specified function is set on a pulse generator applying the pulse pattern.
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