| 摘要 |
<p>PURPOSE:To realize an automatic correction system which corrects a relatively inexpensive timer periodically by accessing the time signal service of a commercial communication circuit and comparing corresponding tones of the timer with various tones of the time signal service. CONSTITUTION:A timer signal service '117' is dialed through an NCU (network control unit) 7 by automatic dialing 6 periodically, e.g. once a day under the control of a control part 1. Then tones of time information on 1sec, 10sec, and 30sec are outputted to a frequency detecting part 11 to detect the time in second units. The detected time is compared by a comparing circuit 12 with a time displayed in second units on the counter in the timer 8. Consequently, an increased or decreased value is detected and then sent to a correcting circuit 13 to make a fast/slow adjustment. The corrected time is sent to the control part 1 and a correcting circuit 13 and corrections are made until the corrected value becomes zero; when the value reaches zero, an end signal is sent to the control part 1 and the reception of the time service is finished.</p> |
