| 摘要 |
PURPOSE:To measure the counter electromotive force of a DC motor without receiving influence of a current flowed through a DC bus by measuring the terminal voltage of the motor under the conditions that the bus is zero. CONSTITUTION:A zero detector 6 inputs a gate signal pulse for a thyristor from a gate signal pulse generator 5 via a current detector 4 and applies a signal to a latch 7 during the period that the DC bus current is zero after the gate signal is inputted. The latch 7 latches the voltage between the DC bus from a voltage detector 2 as the counterelectomotive voltage of a DC motor 8 by the output of the detector 7. Thus, the counter electromotive voltage of the motor can be measured without receiving influence of the current flowed to the bus. |
