A unit of electrical power. One watt is the power delivered by one volt at a current of one ampere in a DC circuit, and one volt at one ampere with a phase angle of 0 degrees in an AC circuit.
A graphical representation of a varying quantity. The x (horizontal) axis usually represents time and the y (vertical) axis usually represents amplitude, energy, or power.
Equal noise energy per hertz.
A microphone cover designed to reduce extraneous noises caused by gusts of wind. Also useful for reducing pop from speech plosives such as “b”, “p”, and “t”.
An intercom or telephone line that carries both audio and DC voltage / current. As opposed to a dry line that carries only the audio.
The symbol for volt-ampere. A volt-ampere describes the demand on the power line without regard to power factor or true power. This figure is more helpful in determining the maximum load on a circuit, that has a given ampere rating.
The term for electrical potential of electromotive force. See IR drop.
Volume Units.
Used to show the relative levels of signals. A change of one VU is a change of one dB. VU meters have their 0 VU point referenced to different levels. This level may be 0 dBm, +4 dBm (Recording Industry), +8 dBm (Broadcast Industry). In addition, correct calibration is further involved. The VU Meter has certain characteristics tailored for monitoring sound. Generally speaking the audio peaks are 10 dB above the indications shown on a standard VU meter due to the lag of the meter. Some VU meters are combined with peak reading meters. Levels stated in “VU”s generally apply to program material. Readings in dBm generally apply to a steady state sine-wave.
supply operates a string of belt pack or other user stations in an isolated, balanced mode. The balanced system is transformer coupled into the regular unbalanced system.
V
VThe symbol for volt.
VA
Voltage
Voltage Drop
VU
VU Meter
W
WThe symbol for the unit of power, the watt.
Watt
Wave Form
White Noise
Windscreen
Wet Line
X
Y
Z
150 H a n d b o o k o f I n t e r c o m S y s t e m s E n g i n e e r i n g
