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Plate #2__ Mains Powered CCTV Systems


The basic CCTV installation is shown in diagram 5 where the camera is mains powered as is the monitor. A coaxial cable carries the video signal from the camera to the monitor




Plate #3__ Video Switcher

This arrangement allows for a great deal more flexibility in designing complex systems. When more than one camera is required, then a video switcher must be included as shown in diagram 6. Using this switcher any camera may be selected to be held on the screen or it can be set to sequence in turn through all the cameras.




Plate #4__ Multiple Camera System

Cameras may be used indoors or outdoors. When used outdoors they will always require a protective housing. For indoor use the environment or aesthetic constraints will dictate whether a housing is needed. Systems may contain a combination of both fixed and movable cameras.




Plate #5__ Movable Cameras

So far all the cameras shown have been fixed with fixed focal length lenses. In many applications the area to be covered would need many fixed cameras. The solution to this is to use cameras fixed to a movable platform. This platform can then be controlled from a remote location. The platform may simply rotate in a horizontal plane and is generally known as a scanner. Alternatively the platform may be controllable in both horizontal and vertical planes and is generally known as a pan, tilt unit. A basic system is illustrated in diagram 8.

This chapter does not deal with how cameras are controlled or wired; it is just showing the facilities that may be incorporated into a CCTV system. Therefore the diagrams that follow are simply descriptive block diagrams and not connection drawings.
















Plate #6__ Systems with Video Recording


With this arrangement the pictures shown during play back will be according to the way in which the switcher was set up when recording. That is, if it was set to sequence then the same views will be displayed on the monitor. There is no control over what can be displayed. 





PLATE #7__ JUNCTION BOX METHOD


A solution to this problem is called a “junction box”, or a “star”. It acts like a hub and each mod jack or phone jack will be wired separately and exclusively back to the junction box. It takes more cable, but is more reliable. The illustration below shows a basic-house-wiring-diagram for residential phone systems.


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PLATE #8__ JUNCTION BOX METHOD

A solution to this problem is called a “junction box”, or a “star”. It acts like a hub and each mod jack or phone jack will be wired separately and exclusively back to the junction box. It takes more cable, but is more reliable. The illustration below shows a basic-house-wiring-diagram for residential phone systems.









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