| 摘要 |
PURPOSE:To prevent the rotating speed of a DC motor from disordering due to the increase in the load torque by interposing a rectifier between the collector and the control input of a transistor for driving the DC motor. CONSTITUTION:When the rotating speed of a DC motor 6 varies, the potential of a motor connecting terminal 4 varies, and the potential of a midpoint divided by resistors 30, 31 alters. Thus, the collector currnet of a transistor 15 of a differential amplifier decreases or increases, and the collector currents of drive transistors 21-24 decreases or increases. A rectifier 33 limits the base current of an emitter follower 20 and the excess base currents of the parallel transistors 21-24 of current mirror coupling when the collector voltage of the transistor 22-24 decreases to prevent the saturation of the transistors 22-24. |
