| 摘要 |
<p>The electric motor drive for the cine camera (1) is provided with a solenoid clutch which is energised to decouple the drive. The motor speed is compared with a programmed value, if the two differ by a set amount then the drive is disconnected by the clutch and the motor speed is corrected by the control. The clutch operates at the start and finish of the scene. When the camera is switched on, the motor is stationary and the difference between the motor speed and the programmed value causes the clutch to operate and disconnect the drive until the speed is correct. The clutch remains without current during the scene. When the scene is finished, the new programmed speed is nil and the motor is running. The clutch is again energised so that the filming stops while the motor slows under its insertia. The current drain the to the clutch is thus minimised.</p> |
