摘要 |
A television or other signal is received via main and duplicate feeds into respective buffers. Should the main feed suffer interruption or disturbance the output is switched at a switch over to the duplicate feed, but in a staged process. Upon initial detection of disturbances read-out from the main buffer is performed using locally generated timing signals in lieu of timing signals obtained from the incoming signal. If however the disturbance s persist the two buffers are synchronized and switchover performed. |