| 摘要 |
PURPOSE:To easily detect abnormality by detecting a difference between coil voltage induced by exciting timing letting speed electromotive force positive and that induced by exciting timing letting the speed electromotive force negative. CONSTITUTION:A phase acting as point A is selected from the exciting timing of interruption, a selection signal is sent to an A/D converter 64, and the coil voltage VA of the same phase is read from the A/D converter 64 and stored into a memory 63. At the same time, a flag telling that the voltage at point A has been read is set up. Exciting timing at that time selects a phase acting as point B and the coil voltage VB of said phase is read and stored into the memory 63. If a voltage difference does not exceed the fixed threshold, it is judged to be out of step and out-of-step processing is performed. |
