| 摘要 |
PURPOSE:To eliminate an abnormal transient response at switching by forming an automatic frequency control system relating to voltage controlled oscillators of each automatic frequency control system of an active system and a spare system. CONSTITUTION:The oscillated frequency of a voltage controller 24b in a spare system is kept to the state of the same frequency at normal state to the oscillated frequency of a voltage controlled oscillator 24b in an active system at normal operation of an automatic frequency controller 7a of the active system via an automatic frequency control system between the active and spare system. If a fault takes place in the automatic frequency controller 7a, an automatic frequency controller 7b takes over the normal operating state instead. |
