| 摘要 |
PURPOSE:To enable self-running with the frequency stored up to now, by providing the phase synchronizing oscillator operated in following to the input synchronizing signal with the digital carrier multiplex unit and detecting the missing of input synchronizing signal or phase shift. CONSTITUTION:The phase detector 9 detects the phase difference between the input synchronizing signal and the output signal of the voltage controlled type crystal oscillator 14 being the output of the phase synchronizing oscillator 8. The detection output is given to the rate amplifier 10 and the integrator 11 with branching, it is added with the adder 12 and converted into the output signal averaged in timing. This signal is returned to the control input of the oscillator 14 via the selector 13. The output of the adder 12 is inputted also to the memory unit 15 and the output is inputted to the selector 13. The output of the oscillator 14 is phase synchronized to the input synchronizing signal with the phase synchronizing loop in the response speed determined with the time constant of the rate amplifier 10 and the integrator 11 at all times. |
