| 摘要 |
<P>PROBLEM TO BE SOLVED: To satisfy both evasion of circuit damage due to high speed rotation caused by strong wind and driving of a high voltage motor. <P>SOLUTION: A power supply for a blower motor is constituted by inverting a DC power supply or a false DC power supply obtained by rectifying and smoothing an AC power supply into a false AC power supply of arbitrary frequency and voltage using a pulse width modulation means, and a means for detecting the current between the DC power supply and the pulse width modulation means is provided. When the polarity of a detected current coincides with the moving direction of energy from the pulse width modulation means to the DC power supply, the phase of a false AC current generated from the pulse width modulation means is regulated while substantially matching the amplitudes of the false AC current and the DC power supply voltage such that the current level becomes very small or the current flows reversely. Consequently, the terminal voltage of the motor can be lowered, components of low withstand voltage can be used in the DC portion and an efficient motor having a high power generation voltage can be used. <P>COPYRIGHT: (C)2008,JPO&INPIT |
