| 摘要 |
PURPOSE:To provide the method of speed voltage detection of an electromagneticaly driven apparatus without a separate sensor, low in cost, high in accuracy, light in weight and small in size and, further, applicable to various external environments. CONSTITUTION:A detecting resistor is connected to the drive terminal of an electromagneticaly driven apparatus in series. A voltage (a).(er) obtained by multiplying a voltage between the terminals of the detecting resistor with a certain value and a voltage obtained by differentiating the voltage between the terminals of the detecting resistor with a time are substracted from a voltage (em) between the drive terminals of the electromagneticaly driven apparatus to obtain a speed voltage. |
