| 摘要 |
PURPOSE:To control a motor even when the load of the motor is increased at the time of a low temperature by connecting a diode in the forward direction to an emitter in a transistor. CONSTITUTION:A PWM signal (a) from a motor 4 is converted into DC voltage proportional to the pulse width of the signal (a) by an integrating circuit 1, and applied to a base in a transistor 2. The speed of the motor 4 is controlled by the variation of currents flowing through the transistor 2. The forward voltage of a diode 3 is increased by the temperature characteristics of diode itself at the time of a low temperature, and the emitter voltage of the transistor 2 is elevated. Collector currents flowing through the transistor 2 reduce by the rise of the emitter voltage, and currents flowing into a motor drive amplifier 5 from an output terminal 6 are increased, thus swelling the number of revolution of the motor 4. |
