| 摘要 |
PURPOSE:To enable synchronized pull-in instantaneously after a power source is applied on by detecting how much the synchronizing signal of a self station is advanced to that of a high-order station by the application the power source, and immediately adjusting timing for transmitting the synchronizing signal of the self station. CONSTITUTION:When the power source of the system is applied, a power source application detection circuit 7 detects it and outputs a power source application signal E and when this signal E is outputted, an absolute value difference detection circuit 8 outputs a half value signal F to a reset pulse preparation circuit 10 based on time difference signals C and D. On the other hand, when the power source application detection circuit 7 outputs the power source application signal E, a control direction detection circuit 9 detects it based on the time difference signals C and D whether time difference (c) or (d) expressed by these signals is larger, and outputs a control signal G expressing the result to the reset pulse preparation circuit 10. Based on the signal F from the absolute value difference detection circuit 8, the reset pulse preparation circuit 10 outputs a reset pulse to a frequency divider circuit 3 so as to fasten the transmission of transmission timing A only for ¦c-d¦/2. Thus, after the power source is turned on, synchronized pull-in can be executed instantaneously. |
