| 摘要 |
<p>PURPOSE:To enable the stable tape tension control in simple constitution without needing a large current by utilizing a discharge voltage of a capacitor for an on-off control of a solenoid. CONSTITUTION:The solenoid 26 of a self-hold type is turned on when a pulse signal is given to terminals 27 and 29, and is turned off when the pulse signal is given to terminals 28 and 29. By turning a power source 21 on, a charge and discharge circuit 24 is charged by the power source 21. Afterward, in a charge and discharge changeover circuit 25, a transistor (Tr) 30 is turned on when a control for the solenoid is given from a terminal 19 to a base of the Tr 30, and Trs 33 and 34 are turned on by a voltage from a power source 22. In addition, Trs 35 and 23 are turned off. Consequently, the circuit 24 is discharged, and a prescribed electric potential is given in between the terminals 27 and 29 of the solenoid 26, so that the solenoid 26 is turned on. Then, this on-state is maintained until a solenoid-off signal is given to a terminal 20. By this method, the stable tape tension control is feasible without needing a large current but with simple constitution.</p> |
