Abbreviation for "ampere" a unit of electrical current
absorption
Loss or dissipation of energy as it travels through a medium, Example: radio waves lose some of their energy as they travel through the atmosphere.
AC
Abbreviation for "Alternating Current"
acceptor atoms
Trivalent atoms that accept free electrons from pentavalent atoms
AC coupling
Circuit that passes an AC signal while blocking a DC voltage.
AC/DC
Equipment that will operate on either an AC or DC power source.
AC generator
Device used to transform mechanical energy into AC electrical power.
AC load line
A graph representing all possible combinations of AC output voltage
and current for an amplifier.
AC power supply
Power supply that delivers an AC voltage.
active component
A component that changes the amplitude of a signal between input and output.
active filter
A filter that uses an amplifier in addition to reactive components to pass or reject selected frequencies.
active region
The region of BJT operation between saturation and cutoff used for linear amplification.
AC voltage
A voltage in which the polarity alternates.
ADC
Abbreviation for "analog to digital converter"
Admittance
(symbol "Y") Measure of how easily AC will flow through a circuit. Admittance is the reciprocal of impedance and is measured in siemens.
AF
Abbreviation for "audio frequency".
AFC
Abbreviation for "automatic frequency control".
AGC
Abbreviation for "automatic gain control"
alligator clip
Spring clip on the end of a test lead used to make a temporary connection.
alpha
Ratio of collector current to emitter current in a bipolar junction transistor (BJT). Greek letter alpha "a" is the symbol used.
alternator
Name for an AC generator.
AM Abbreviation for "amplitude modulation"
ammeter
A meter used to measure current.
ampere
Unit of electrical current.
amplifier
A circuit that increases the voltage, current, or power of a signal.
amplitude:
Magnitude or size of a signal voltage or current.
analog
Information represented as continously varying voltage or current rather than in discrete levels as opposed to digital data varying between two discrete levels.
anode The positive electrode or terminal of a device. The "P" material of a diode.
antenna, transmitting
A device that converts an electrical wave into an electromagnetic wave that radiates away from the antenna.
antenna, receiving
A device that converts a radiated electromagnetic wave into an electrical wave.
apparent power
Power attained in an AC circuit as a product of effective voltage and current which reach their peak at different times.
arc
Discharge of electricity through a gas such as lightning discharging through the atmosphere.
armature:
The rotating or moving component of a magnetic circuit.
astable multivibrator
An oscillator that produces a square wave output from a DC voltage.
atom
The smallest particle that an element can be broken down into and still maintain its unique identity.
atomic number
The number of positive charges or protons in the nucleus of an atom.
attenuate
To reduce the amplitude of an action or signal. The opposite of amplification.
autotransformer
A single winding transformer where the output is taken from taps on the winding.
average value
A value of voltage or current where the area of the wave above the value equals the area of the wave below the value.
AVC
Abbreviation for "automatic volume control"
avionics
Aviation electronics.
AWG
Abbreviation for "american wire gauge". A gauge that assigns a number value to the diameter of a wire.
=================================== =============== =======================
B
balanced bridge
Condition that occurs when a bridge circuit is adjusted to produce a zero output.
band-pass filter
A tuned circuit designed to pass a band of frequencies between a lower cut-off frequency (f1) and a higher cut-off frequency (f2). Frequencies above and below the pass band are heavily attenuated.
band-stop filter
A tuned circuit designed to stop frequencies between a lower cut-off frequency (f1) and a higher cut-off frequency (f2) of the amplifier while passing all other frequencies.
bandwidth
Width of the band of frequencies between the half power points.
barrier potential
The natural difference of potential that exists across a forward biased pn junction.
base
The region that lies betwen the emitter and collector of a bipolar junction transistor (BJT).
base biasing
A method of biasing a BJT in which the bias voltage is supplied to the base by means of a resistor.
battery
A DC voltage source containing two or more cells that convert chemical energy to electrical energy.
baud
A unit of signaling speed equal to the number of signal events per second. Not necessarily the same as bits per second.
beta
(b) The ratio of collector current to base current in a bipolar junction transistor (BJT).
bias
A DC voltage applied to a device to control its operation.
binary
A number system having only two symbols, 0 and 1. A base 2 number system.
bipolar junction transistor
(BJT), A three terminal device in which emitter to collector current is controlled by base current.
bistable multivibrator
A multivibrator with two stable states. An external signal is required to change the output from one state to the other. Also called a latch.
bleeder current
A current drawn continously from a souce. Bleeder current is used to stabilize the output voltage of a source.
bode plot
A graph of gain versus frequency.
branch current
The portion of total current flowing in one path of a parallel circuit.
breakdown voltage
Voltage at which the breakdown of a dialectric or insulator occurs.
breakover voltage
Minimum voltage required to cause a diac to break down and conduct.
bridge rectifier
A circuit using four diodes to provide full wave rectification. Converts an AC voltage to a pulsating DC voltage.
buffer
An amplifier used to isolate a load from a source.
bulk resistance
The natural resistance of a "P" type or "N" type semiconductor material.
butterworth filter
A type of active filter characterized by a constant gain (flat response) across the midband of the circuit and a 20 dB per decade roll-off rate for each pole contained in the circuit.
BW
Abbreviation for bandwidth.
bypass capacitor
A capacitor used to provide an AC ground at some point in a circuit.
byte
Group of eight binary digits or bits.
الجمعة سبتمبر 14, 2012 10:01 am من طرف محمد المندلاوي
» انواع دايود الليزر
الجمعة سبتمبر 14, 2012 9:58 am من طرف محمد المندلاوي
» ماهو الغشاء الرقيق؟
الجمعة سبتمبر 14, 2012 9:49 am من طرف محمد المندلاوي
» حروف تدل على شخصية المراة ؟؟
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» خاطرة ...!
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