| 摘要 |
PURPOSE:To avoid malfunction by using current signal passed through a filter to eliminate influences of a carrier wave for the purpose of detection of a stall state. CONSTITUTION:The output current of a transistor inverter 5 is detected by a current transformer 21 and converted to a DC voltage signal by a rectifier 22 and a resistor 23. A signal obtained across the resistor 23 passes through a filter 30, and turn out to be a current signal free from the ripple components due to a carrier wave. If this current signal applied to a stall comparator 25 has a value greater than that set by the stool comparator 25, then the signal is fed to an acceleration/deceleration calculator 12 so that the output from the calculator 12 is temporarily prohibited from varying. |
