| 摘要 |
PURPOSE:To maintain the rotary speed of a motor stably even with a controller having simple structure, regardless of the variation of motor load, by switching the resistors to be connected with the motor according to the voltage to be applied onto the motor thereby varying the motor current. CONSTITUTION:When a motor 1 is started, resistance in a resistance circuit 4 is switched sequentially to a lower value in order to prevent overflow of motor current. Upon finish of start control, an ECU 22 grounds the terminals (1, 2), respectively, according to a detected motor voltage thus switching the resistance of the resistance circuit 4. Consequently, switching of the resistance in the resistance circuit 4 is stopped when the motor current reaches a level corresponding to the motor load, i.e., when the actual drive torque matches with the torque demanded by the motor 1. By such arrangement, rotary speed of motor can be maintained constant regardless of the variation of motor load and thereby a rotary speed controller for motor having simple structure can be obtained with low cost. |
