| 摘要 |
PURPOSE:To maintain the tension of a tape wound on a reel constant by selecting the resistance value of a controller for supplying a voltage to a motor and the gain of an amplifier, and setting the counterelectromotive force of the starting end of the winding twice of that of the finishing end. CONSTITUTION:A bridge circuit 6 is formed of a motor 5 for winding a tape which is fed at the constant speed and resistors 7, 8, the counterelectromotive force obtained from an operational amplifier 10 and a motor current due to the resistor 9 are inputted to an operational amplifier 13 to control a transistor 14, and the voltage applied to the bridge circuit 6 is controlled so that the both inputs of the amplifier 13 become equal. At this time resistors 11, 17 for deciding the values of the resistors 8, 9 and the gain of the amplifier 10 are selected, and set so that the counterelectromotive force of the starting end of the winding is twice of that of the finishing end. Accordingly, the product of the motor current and the counterelectromotive force is always constant, and the tension applied to the tape can be maintained constantly. |
