| 摘要 |
PURPOSE:To eliminate a special circuit for generating a weakening magnetic flux pattern by providing the amplitude of a magnetic flux command value with a constant value over the entire frequency range irrespective of the bases frequency to inverter-control it. CONSTITUTION:A frequency command from a frequency command setter 1 is applied to a V/F converter 2 which converts it into a pulse signal proportional to the frequency. A counter 3 reads out a unit sinusoidal signal from a sinusoidal ROM 4 by counting the pulse signal. A D/A converter 5 is composed of a type that the peak value of a sinusoidal signal is, for example, applied externally as an analog amount and therefore can obtain a magnetic flux command value of an analog amount of a predetermined amplitude with a constant value externally applied to it.
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