Abstract: Several cameras (12, 14, 16) have their composite-video outputs sent to a common switcher (24), which picks one of the outputs and sends it to a modulator (26) to be placed on a carrier and sent by antenna (28) to a central broadcast station. A central timing circuit or driver (30) sends master signals to signal-generating circuits (34, 36, 38), which receive the outputs of the cameras (12, 14, 16) and automatically adjust their output timing so that their synchronization signals are received in synchronism at the switcher (24). Timing comparators (62, 88) compare the timing of sync and subcarrier signals in the camera output with similar signals from the driver and in response control voltage-controlled oscillators (78, 104) that provide timing for the sync signals and color-burst signals that are sent to the cameras.

Abstract: A video surveillance system having a plurality of video cameras and means for reproducing the scenes viewed by a selected by one of the cameras. A switch selectively connects the cameras to the reproducing means. A counter generates a sequence of signals wherein each signal corresponds to one of the cameras. The counter signals are applied to the switch to select the corresponding camera and apply its output to the reproducing means. The counter signals are also applied to a character generator which generates characters identifying the selected camera for display at a selected location in the reproduced scene.

Abstract: A video surveillance system which records the outputs of a plurality of video cameras in sequence normally operates in a time lapse mode so that video signals are recorded at spaced intervals of time to conserve video recording tape. When an emergency situation occurs in the installation being surveilled, an alarm button is depressed which automatically switches the system into a real time mode in which the video signals are recorded continuously so that there is no loss of useful information during the emergency.