| 摘要 |
PURPOSE: A handpiece with the corrected speed of revolution of a small motor is provided to precisely polish the surface of an object by constantly maintaining the speed of revolution. CONSTITUTION: A motor controller (11) includes a speed control switch (10). A current sensing circuit (12) is formed between a motor (2) and a motor controller. An amplifier (13) amplifies a current sensed by the current sensing circuit. A current and negative voltage converter (14) generates a compensation value which is suitable for the amplified current. A speed compensation limiting unit (15) limits a maximum speed. [Reference numerals] (11) Motor controller Power control unit; (12) Current sensing circuit; (13) Amplifying unit; (14) Current change→subvoltage changing unit; (15) Limit (speed compensation limiting unit) |
