| 摘要 |
PURPOSE:To reduce power loss and a current ripple, and to obtain high speed resolution by a method wherein the amount denied by the positive and inverse pulse voltage by each other is restrained at the minimum value while being divided into two portions for every period and is applied to a motor. CONSTITUTION:Positive and inverse pulse voltage are applied to the DC motor 32 by using four transistors Tr 11-14, and speed is controlled by the difference. In this case, comparison signals VS and controlling input Vr2, Vr1 are each compared to a fundamental triangular wave VBO at a fixed period, four I-IV sections are formed for every each period, and the positive and inverse direction voltage sections I, III are each generated two by two for one period. The Trs 11, 14 and the Trs 12, 13, for example, are each ON in the sections I, III, the motor is turned forward by the difference section, the width of the section I is changed to great or small size by the controlling input Vr1 and speed is controlled. Accordingly, since the amount denied by a positive period and an inverse period can be restrained at the minimum, the power loss and the current ripple are reduced, and speed resolution can be increased. |
