| 摘要 |
PROBLEM TO BE SOLVED: To make a relation station hold the phase synchronization of a basic frequency even when a transmitting station intermittently operates by holding an input voltage to a voltage control oscillator when in data propagation and applying a hold input voltage to the oscillator when in non-propagation. SOLUTION: A flip-flop circuit 16 samples transmission data 100 by the output signal of the voltage control oscillator 14, synchronizes it with a synchronizing frequency, and generates reproducing transmission data 102a. In this state, if the propagation of the transmission data 100 is stopped on a transmission path 3, the output of a multivibrator 8 keeps a high level, so that both switch circuits 9 and 12 are kept being switched on a II and a IV sides, respectively. Thus, like the output signal of a circuit 12, a constant voltage which is charged in a capacity 11 is applied to the oscillator 14. Since this constant voltage is an input voltage to the voltage control oscillator 14 at the time when phase synchronization is performed based on the transmission data propagated before, the output of the voltage control oscillator 14 maintains the phase synchronization state even if transmission data is not inputted. |
