| 摘要 |
PURPOSE:To readily control the conversion between normal and reverse rotation of a DC motor and variable speed operation and brake by composing a tape drive device of an electric circuit having transistors and diodes. CONSTITUTION:When a normal rotation instruction switch 34 is set to a contact F and a reverse rotation instruction switch 35 is set to a contact S, a transistor 28 is conducted, while a transistor 29 is interrupted, thereby allowing a transistor 22 to be interrupted and a transistor 23 to be conducted. A Darlington transistor 20 supplies a voltage in response to the control voltage 36 to a motor 2. Thus, the motor 2 rotates normally. When the switch 34 is then connected at the contact S, the transistors 22, 28 are interrupted, and the transistor 22 is conducted. In this manner, the motor 2 is shortcircuited through a diode 27 and the transistor 22, and abruptly electromagnetically braked. |
