| 摘要 |
PURPOSE:To enable always accurate time display, by controlling the drive motor through the lead and lag of the renewal operation of the leaf plate. CONSTITUTION:The 60X60 notation counter 14 to which 1Hz signal of the frequency dividing circuit 4 is given, produces the period signal every one hour, and this is output to the lag lead discrimination circuit 16. On the other hand, from the specified leaf retaining spring 36, the renewal signal every one hour corresponding to the period of renewal of the leaf plate is picked up and fed to the discrimination circuit 16. Next, the discrimination circuit 16 discriminates the lag and lead of both the inputs and gives the result to the control circuit 6 to control the rotation of the motor 12. That is, the control circuit 6 adds the correction drive pulse in case of lag and blocks the passage of drive pulse in case of lead. Thus, accurate time display can always be made. |
