A block diagram of a standard home television
system is shown in figure 8-3. There are three main
A pickup unit, generally referred to as the camera,
divisions in the diagram. The top division represents
starts the sequence of events that occurs in the CCTV
the video or picture section of the transmitter. The
system. A lens in the camera focuses an image on a
central division represents the audio or sound section
photosensitive (light-sensitive) tube. The type of lens
of the transmitter. The lower division represents the
is determined by the size of the scene to be televised.
It maybe a normal, wide-angle, or telephoto lens. The
size of the camera unit varies from small palm size
mobile units to large units mounted on special
platforms. One or more cameras may be connected
into the system to receive the desired picture (video)
A CCTV system consists of three basic units.
and route it as an electronic signal to a control unit
These basic units are the camera(s), or pickup unit(s),
the control unit, and the monitor(s) (fig. 8-4).
Figure 8-3.--Simplified block diagram of a commercial television.