| 摘要 |
PURPOSE:To detect the speed of a motor without necessity of a special sensor such as an encoder or a tachometer generator by using a nonexciting winding as a sensor of a speed signal. CONSTITUTION:When a switch 11 is closed and an exciting current (i) is flowed to a winding 31 in response thereto, a switch 22 or 23 is set to ON state. When a rotor 2 of a permanent magnet is rotated, induced voltage E are generated in the windings 32, 33, 34 of nonexcited state. Of them the induced voltage E of the winding 32 or 33 is inputted through switches 22, 23 of ON state to a waveform shaper 16. The input voltage of this time and hence the induced voltage E has a proportional relation to the rotating speed of the rotor 2. Thus, the rotating speed of the motor 1 is indirectly measured by the output voltage of the shaper 16. |
