| 摘要 |
PURPOSE:To suitably notify the timing of a brush exchange by generating an alarm when a pulse voltage superposed on the terminal voltage of a motor exceeds the prescribed value. CONSTITUTION:The terminal voltage of a motor M is inputted through an input unit 1 to a peak detector 2, the maximum value is detected, and supplied to a comparator 4. A reference value setter 3 sets a suitable value in response to a brush noise voltage, and supplies the value to the comparator 4. The comparator 4 compares a signal from a peak detector 2 with the voltage of the setter 3, supplies an output signal to an alarm unit 5 when the signal higher than the voltage of the setter 3 is supplied from the detector 2, thereby notifying the brush exchange. |
