CCTV Glossary of Terms "U-Z"

Uninterrupted Power Supply (Ups)


Equipment that supplies power to a system in the event the primary power is lost. It may consist of batteries or auxiliary motor generators.

Unterminated (Hi-Z)

Video input of a piece of CCTV equipment, wired so as to allow the video signal to be fed to further equipment. Does not necessarily include extra sockets for the extra coaxial cables.

Varifocal Lens

See Zoom Lens. Usually not motorized (manual).

VCR

A device that records video images on tape.

Vertical Interval Switching

Sequential switchers waiting until the current field has finished before they display the next camera, even though the dwell time has elapsed.

Vext

A multiplexer feature that uses a pulse generated by the VCR so that the multiplexer automatically adjusts to the VCR time lapse speed.

Video Motion Detection (V.M.D.)

A system that uses the video signal from a camera to determine if there is any movement in the picture and set of an alarm.

Video Printer

A device that prints a hard copy image from a video signal.

Video Type Lens

An auto-iris lens without an internal circuit to control the iris. All iris control voltages come from a circuit located within the camera.

Visible Light

Wavelengths of light visible to the human eye.

VSS

The best place to purchase CCTV equipment, and receive the utmost in technical and design assistance.

Wavelet

A digital file commonly used in digital recording, which contains a representation of sound waves in digital form; limited in duration and frequency.

White Light

The entire spectrum of visible light.

Y/C

A method of sending video pictures in 2 separate parts down 2 separate cables. The component parts are Y (the Black and White portion) and C ( the color portion).

Zoom

The ability to change the magnification of a scene.

Zoom Lens

A lens with a variable focal length. This lens may be effectively used as a wide angle, standard, or telephoto lens by varying the focal length of the lens. A varifocal lens.

Zoom Ratio

The ratio of starting focal length (wide position) to the ending focal length (telephoto position) of a zoom lens. Typically 10X.