| 摘要 |
PURPOSE:To prevent a DC motor from generating vibrations when the motor is operated at a low torque and low rotating speed by dividing the duty ratio of the energizing time of the motor against the energizing interval of the motor into a prescribed number of stages and making the energizing time shorter when its duty ratio is smaller at every stage. CONSTITUTION:The non-energizing time of a DC motor 1 to be controlled is controlled by feeding back by intermittently energizing the motor 1 and feeding back the electric power generating quantity of the motor against a control value instructing the rotating speed of the motor 1. In such a method for controlling the speed of the DC motor, the duty ratio of the energizing time of the DC motor 1 to be controlled is divided into a plurality of number of stages and the energizing time of the motor 1 is switched to a shorter time when the duty ratio is smaller at every stage. For example, a pulse generating means 3 is made to switch the pulse width of its output pulse to a prescribed state in accordance with a mean voltage detected by a switching control means 6. |
