| 摘要 |
PURPOSE:To improve the stability of the rotational speed of a drum motor and to reproduce an excellent TV picture, by changing the driving force of a drum motor at the time of frame forwarding operation synchronously to the driving and stopping of a capstan motor. CONSTITUTION:When a start signal is inputted from a terminal 25 and a capstan motor 5 starts the tape forwarding operation from the stopping condition, a switching circuit 33 is set to the (c) side and the driving force of a drum motor 2 is increased. Moreover, when a monostable multivibrator 20 operates and a capstan motor stopping signal is outputted, the driving of the motor 5 is stopped and, at the same time, the switching circuit 33 is switched to the (d) side for a prescribed period by a switch signal generating circuit 19 and, thereafter, the circuit 33 repeates operations to return to the (e) side during the frame forwarding operation. In addition to the above, a voltage which lowers the driving force of te motor 2 is selected for a power source 35 and the speed of the motor 2 is stabilized against the drop in tape tension when the driving force of the motor 5 is turned off by adding voltage of the power source 35 through a resistance 34. Therefore, the cycle of a reprodoced horizontal synchronizing signal is stabilized and, as a result, excellent pictures can be obtained.
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