Electronic terms, glossary of electronic terms, electronic terms
starting from alphabet V, Collection of Electronic Definitions, electronic
Acronyms and terms related to electronic industry
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voltage source
- Circuit or device that
supplies voltage to a load.
voltaic cell
- Primary cell having two
unlike electrodes immersed in a solution that chemically
interacts to produce a voltage.
volt-ampere
- Unit of apparent power
in an AC circuit containing capacitive or inductive reactance.
Apparent power is the product of source voltage and current.
voltmeter
- Instrument used to
measure difference in potential between two points.
volume
- Magnitude or power
level of audio frequency. Measured in volume units (VU).
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VA
- Abbreviation for "volt
ampere"
vacuum tube
- Electron tube evacuated
to such a degree that its electrical characteristics are
essentially unaffected by the presence of residual gas or
vapor. Have been essentially replaced by transistors for
amplification and rectification. Cathode ray tubes are still
used as display devices.
valence shell
- The outermost electron
shell for a given atom. The number of electrons in this shell
determines the conductivity of the atom.
varactor diode
- PN junction diode with
a high junction capacitance when reverse biased. Most often
used as a voltage controlled capacitor. The varactor is also
called: varicap, tuning diode and epicap.
variable capacitor
- Capacitor whose
capacitance can be change by varying the effective area of the
plates or the distance between the plates.
variable resistor
- Resistor whose resistance can be
changed by turning a shaft. See also "potentiometer and
rheostat."
VCR
- Abbreviation for "video
cassette recorder."
vector
- Quantity having both
magnitude and direction. Normally represented by a line.
Length of the line indicates magnitude and orientation
indicates direction.
vector diagram
- Arrangement of vectors
showing phase relationships between two or more AC quantities
of the same frequency.
vertical MOS
- Enhancement type MOSFET
designed to handle much greater values of drain current than
standard E-MOSFET.
very high frequency
- (VHF) Electromagnetic
frequency band from 30 MHz to 300 MHz.
very low frequency
- (VLF) Frequency band
from 3 kHz to 30 kHz.
video
- Relating to any picture
or visual information. From the latin word meaning "I see."
video amplifier
- Amplifier having one or
mare stages designed to amplify video signals.
virtual ground
- Point in a circuit that
is always at approximately ground potential. Often a ground
for voltage, but not for current.
voice coil
- Coil attached to the
diaphragm of a moving coil loudspeaker. The coil is moved
through an air gap between magnetic pole pieces.
voice synthesizer
- Synthesizer that can
simulate speech by stringing together phonemes.
volt
- Unit of potential
difference or electromotive force. One volt is the potential
difference needed to produce one ampere of current through a
resistance of one ohm.
voltage
- (V) Term used to
designate electrical pressure or force that causes current to
flow.
voltage amplifier
- Amplifier designed to
build up signal voltage. By design amplifiers can have a large
voltage gain or a large current gain or a large power gain.
Voltage amplifiers are designed to maximize voltage gain often
at the expense of current gain or power gain.
voltage controlled oscillator
- Oscillator whose output
frequency depends on an input control voltage.
voltage divider
- Fixed or variable
series resistor network connected across a voltage to obtain a
desired fraction of that voltage.
voltage divider biasing
- Biasing method used
with amplifiers in which two series resistors connected across
a source. The junction of the two biasing resistors provides
correct bias voltage for the amplifier.
voltage drop
- Voltage or difference
in potential developed across a component due to current flow.
voltage feedback
- Feedback configuration
where a portion of the output voltage is fed back to the input
of an amplifier.
voltage follower
- Operational amplifier
circuit characterized by a high input impedance, low output
impedance and unity voltage gain. Used as a buffer between a
source and a low impedance load.
voltage gain
- Also called voltage
amplification. Ratio of amplifier output voltage to input
voltage usually expressed in decibels.
voltage multiplier
- Rectifier circuit using
diodes and capacitors to produce a DC output voltage that is
some multiple of the peak value of AC input voltage. Cost
effective way of producing higher DC voltages. Voltage
doublers and voltage triplers are examples.
voltage rating
- Maximum voltage a
component can withstand without breaking down.
voltage regulator
- Device or circuit that
maintains constant output voltage (within certain limits) in
spite of changing line voltage and/or load current.
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