| 摘要 |
PURPOSE:To enable performing a constraint detection and a supply cut-off at the time of constraint with a simple circuit constitution by positive feedback coupling a rotation detecting transistor to a driving transistor and by turning OFF said rotation detecting transistor after the lapse of a specified time since the driving transistor has been turned ON. CONSTITUTION:When a motor M is forcibly rotated, an induced electromotive force is generated in a terminal T1. If said induced electromotive force exceeds the base-emitter forward voltage of a rotation detecting transistor Q1, the rotation detecting transistor Q1 and a driving transistor Q2 are turned ON and the motor M continues to rotate. On the other hand, when the terminal voltage of a capacitor C1 reaches a specified value, a transistor Q3 is turned ON. In this manner, said transistors Q1 and Q2 are turned OFF. In this case, if the motor M is constrained, the rotation detecting transistor Q1 is not turned ON again. |
