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[align=left]power
Amount of energy converted by a circuit or component in a unit of time, normally seconds. Measured in units of watts. (joules/second).
power amplifier
An amplifier designed to deliver maximum power output to a load. Example: In an audio system, it is the power amplifier that drives the loudspeaker.
power derating factor
A transistor rating that tells how much the maximum allowable value of PD decreased for each 1°C rise in ambient temperature.
power dissipation
Amount of heat energy generated by a device in one second when current flows through it.
power factor
Ratio of actual power to apparent power.
power loss
Ratio of power absorbed to power delivered.
power supply
Electrical equipment used to deliver either AC or DC voltage.
power supply rejection ratio
A measure of an op-amps ability to maintain a constant output when the supply voltage varies.
primary
First winding of a transformer. Winding that is connected to the source as opposed to secondary which is a winding connected to a load.
primary cell
Cell that produces electrical energy through an internal electrochemical action. Once discharged a primary cell cannot be reused.
printed circuit board
Insulating board containing conductive tracks for circuit connections.
programmable UJT
Unijunction transistor with a variable intrinsic stand-off ratio.
propagation
Traveling of electromagnetic, electrical or sound waves through a medium.
propagation delay
Time required for a signal to pass through a device or circuit.
propagation time
Time required for a wave to travel between two points.
protoboard
Board with provision for attaching components without solder. Also called a breadboard. Primarily used for constructing experimental circuits.
proton
Sub atomic particle within the nucleus of an atom. Has a positive charge.
pulse
Rise and fall of some quantity (usually voltage) for a period of time.
pulse fall time
Time for a pulse to decrease from 90% of its peak value to 10% of its peak value.
pulse repetition frequency
The number of times per second that a pulse is transmitted. Pulse rate.
pulse repetition time
Time interval between the start of two consecutive pulses.
pulse rise time
Time required for a pulse to increase from 10% of its peak value to 90% of its peak value.
pulse width
Time interval between the leading edge and trailing edge of a pulse at a point where the amplitude is 50% of the peak value.
push>push-pull amplifier
Amplifier using two active devices operating 180° apart.
Pythagorean theorem
A theorem in geometry: The square of the hypotenuse of a right triangle equals the sum of the squares of the other two sides. In electronics used for vector analysis of AC circuits
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Q
Q
Quality factor of an inductor or capacitor. It is the ratio of a component’s reactance (energy stored) to its effective series resistance (energy dissipated). For a tuned circuit, a figure of merrit used in bandwidth calculations. Q is the ratio of reactive power to resistive power in a tuned circuit. Also the symbol for charge in coulombs (Q for quantity).
quiescent
At rest. For an amplifier the term is used to describe condition with no active input signal.
quiescent point
( A point on the DC load line of a given amplifier that represents the quiescent (no signal) value of output voltage and current for the circuit.
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R
radar
Acronym for "radio detection and ranging" A system that measures the distance and direction of objects.
radioastronomy
Branch of astronomy that studies the radio waves generated by celestial bodies and uses these emissions to obtain information about them.
radio broadcast
Transmission of music, voice and other information on radio carrier waves that can be received by the general public.
radio communication
Term used to describe the transfer of information between two or more points by use of radio or electromagnetic waves.
radio-frequency amplifier
Amplifier having one or more active devices to amplify radio signals.
radio-frequency generator
Generator capable of supplying RF energy at any desired frequency in the radio-frequency spectrum.
radio-frequency probe
Probe used in conjunction with an AC meter to measure radio-frequency signals.
RC
Abbreviation for "resistance capacitance" also abbreviation for "radio controled" as in "RC model airplanes."
RC time constant
Product of resistance and capacitance in seconds.
reactance
Symbol "X". Opposition to current flow without the dissipation of energy. Example: The opposition provided by inductance or capacitance to AC current.
reactive power
Also called imaginary power or wattless power. It is the power value in "volt amps" obtained from the product of source voltage and source current in a reactive circuit.
real number
Number having no imaginary part.
receiver
Unit or piece of equipment used to receive information.
recombination
Process by which a conduction band electron gives up energy (in the form of heat or light) and falls into a valence band hole.
rectangular coordinates
A Cartesian coordinate of a Cartesian coordinate system whose straight-line axes or coordinate planes are perpendicular.
rectification
Process that converts alternating current to direct current.
rectifier
Diode circuit that converts alternating current into pulsating direct current.
regulated power supply
Power supply that maintains a constant output voltage under changing load conditions.
regulator
Device or circuit that maintains a desired output under changing conditions.
relay
Electromechanical device that opens or closes contacts when a current is passed through a coil.
relative
Not independent. Compared with or with respect to some other measured quantity.
relaxation oscillator
Free running circuit that outputs pulses with a period dependent or one or more RC time constants.
reluctance
Resistance to the flow of magnetic lines of force.
remanence
Amount a material remains magnetized after the magnetizing force has been removed.
residual magnetism
Magnetism remaining in the core of an electromagnet after the coil current is removed.
resistance
Symbolized "R" and measured in ohms. Opposition to current flow and dissipation of energy in the form of heat.
resistive power
Amount of power dissipated as heat in a circuit containing resistive and reactive components. True power as opposed to reactive power.
resistive temperature detector
(RTD) Temperature detector consisting of a fine coil of conducting wire (such as platinum) that will produce a relatively linear increase in resistance as temperature increases.
receptivity
Measure of a material’s resistance to current flow.
resistor
Component made of material that opposes flow of current and therefore has some value of resistance.
resistor color code
Coding system of colored stripes on a resistor to indicate the resistor’s value and tolerance.
resonance
Circuit condition that occurs at the frequency where inductive reactance (XL) equals capacitive reactance (XC).
reverse bias
Bias on a PN junction that allows only leakage current (minority carriers) to flow. Positive polarity on the n-type material and negative polarity to the p-type material.
reverse breakdown voltage
Amount of reverse bias that will cause a PN junction to break down and conduct in the reverse direction.
reverse current
Current through a diode when reverse biased. An extremely small current also referred to as leakage.
reverse saturation current
Reverse current through a diode caused by thermal activity. This current is not affected by the amount of reverse bias on the component, but does vary with temperature.
RF
Abbreviation for "radio frequency."
rheostat
Two terminal variable resistor used to control current.
right angle triangle
Triangle having a 90° or square corner.
ripple frequency
Frequency of the ripple present in the output of a DC source.
ripple voltage
The small variations in Dc voltage that remain after filtering in a power supply.
rise time
Time for the leading edge of a pulse to rise from 10% of its peak value to 90% of its peak value.
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[align=left]RL differentiator
An RL circuit whose output voltage is proportional to the rate of change of the input voltage.
RL filter
Selective circuit of resistors and inductors that offers little or no opposition to certain frequencies while blocking or attenuating other frequencies.
RL integrator
RL circuit with an output proportionate to the integral of the input signal.
rms
Abbreviation for "root mean square"
rms value
Rms value of an AC sine wave is 0.707 times the peak value. This is the effective value of an AC sine wave. The rms value of a sine wave is the value of a DC voltage that would produce the same amount of heat in a heating element.
roll-off rate
Rate of change in gain when an amplifier is operated outside of its bandwidth.
rotary switch
Electromechanical device that has a rotating shaft connected to one terminal capable of making or breaking a connection to one or more other terminals.
R-2R ladder
Network or circuit composed of a sequence of L networks connected in tandem. Circuit used in digital to analog converters.
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S
saturation
Condition in which a further increase in one variable produces no further increase in the resultant effect. In a bipolar junction transistor, the condition when the emitter to collector voltage is less than the emitter to base voltage. This condition puts forward bias on the base to collector junction.
scale
Set of markings used for measurement.
schematic diagram
Illustration of an electrical or electronic circuit with the components represented by their symbols.
Schmitt trigger
Circuit to convert a given waveform to a square wave output.
scientific notation
Numbers entered as a number from one to ten multiplied by a power of ten. Example: 8765 = 8.765 × 103.
secondary
Output winding of a transformer. Winding that is connected to a load.
secondary cell
Electrolytic cell used to store electricity. Once discharged may be restored by recharging by putting current through the cell in the direction opposite to that of discharge current.
selectivity
Charistic of a circuit to discriminate between wanted and unwanted signals.
self biasing
Gate bias for a field effect transistor in which source current through a resistor produces the voltage for gate to source bias.
self inductance
Property that causes a counter electromotive force to be produced in a conductor when the magnetic field expands or collapses with a change of current.
semiconductor
An element which is neither a good conductor or a good insulator, but rather lies somewhere between the two. Characterized by a valence ****l containing four electrons. Silicon, germanium and carbon are the semiconductors most frequently used in electronics.
series circuit
Circuit in which the components are connected end to end so that current has only one path to follow through the circuit.
series parallel network
Network that contains components connected in both series and parallel.
series resonance
Condition that occurs in a series LC circuit at the frequency where inductive reactance equals capacitive reactance. Impedance is minimum, current is maximum limited only by resistance in the circuit.
seven segment display
Device made of several light emitting diodes arranged in a numeric or alphanumeric pattern. By lighting selected segments numeric or alphabet characters can be displayed.
****ls or bands
Orbital path containing a group of electrons having a common energy level.
shield
****l grounded cover used to protect a wire, component or piece of equipment from stray magnetic and/or electric fields.
short circuit
Also called a short. Low resistance connection between two points in a circuit typically causing excessive current.
shunt resistor
Resistor connected in parallel or in shunt with another component or circuit.
signal
Electrical quantity that conveys information.
signal to noise ratio
Ratio of the magnitude of the signal to the magnitude of noise usually expressed in decibels.
silicon
(Si) Non ****llic element (atomic number 14) used in pure form as a semiconductor.
silicon-controlled rectifier
(SCR) Three terminal active device that acts as a gated diode. The gate terminal is used to turn the device on allowing current to pass from cathode to anode.
silicon controlled switch
An SCR with an added terminal called an anode gate. A positive pulse either at the anode gate or the cathode gate will turn the device on.
silicon transistor
A bipolar junction transistor using silicon as the semi conducting material.
silver
(Ag) Precious ****l that does not easily corrode and is more conductive than copper.
silver mica capacitor
Mica capacitor with silver deposited directly onto the mica sheets instead of using conductive ****l foil.
silver solder
Solder composed of silver, copper and zinc. Has a melting point lower than pure silver, but higher than lead-tin solder.
simplex
Communication in only one direction at a time. Example: FAX.
simulcast
Broadcasting a program simultaneously in two different forms, for example a program broadcast in both AM and FM.
sine
Sine of an angle of a right angle triangle is equal to the opposite side divided by the hypotenuse.
sine wave
Wave whose amplitude is the sine of a linear function of time. It is plotted on a graph that plots amplitude against time or radial degrees relative to the angular rotation of an alternator.
single in-line package
Package containing several electronic components (generally resistors) with a single row of connecting pins.
single pole double throw
(SPDT) Three terminal switch in which one terminal can be connected to either one of the other terminals.
single pole single throw
(SPST) Two terminal switch or relay that can open or close one circuit.
single sideband
(SSB) AM radio communication technique in which the transmitter suppresses one sideband and therefore transmits only a single sideband.
single throw switch
Switch containing only one set of contacts which can be either opened or closed.
sink
Device such as a load that consumes power or conducts away heat.
sintering
Process of bonding either a ****l or powder by cold pressing it into a desired shape and then heating to form a strong cohesive body.
sinusoidal
Varying in proportion to the sine of an angle or time function. AC voltage in which the instantaneous value is equal to the sine of the phase angle times the peak value.
SIP
Abbreviation for "single in-line package."
skin effect
Tendency of high-frequency (rf) currents to flow near the surface layer of a conductor.
slew rate
The maximum rate at which the output voltage of an op-amp can change.
slide switch
Switch having a sliding button, bar or knob.
slow acting relay
Slow operating relay that when energized may not pull up the armature for several seconds.
slow-blow fuse
Fust that can withstand a heavy current (up to ten times its rated value) for a small period of time before it opens.
snap switch
Switch containing a spring under tension or compression that causes the contacts to come together suddenly when activated.
SNR
Abbreviation for "signal to noise ratio."
soft magnetic material
Ferromagnetic material that is easily demagnetized.
software
Program of instructions that directs the operation of a computer.
solar cell
Photovoltaic cell that converts light into electric energy. Especially useful as a power source for space vehicles.
solder
****llic alloy used to join two ****l surfaces.
soldering
Process of joining two ****llic surfaces to make an electrical contact by melting solder (usually tin and lead) across them.
soldering iron
Tool with an internal heating element used to heat surfaces being soldered to the point where the solder becomes molten.
solenoid
An air core coil. Equipped with a movable iron core the solenoid will produce motion. As a result of current through the coil the iron core is pulled into the center of the winding. When the coil is deenergized, a spring pulls the movable core away from the center of the winding. Mechanical devices connected to the movable core are made to move as a result of current through the coil. Example: Electric door locks on some automobiles.
solid conductor
Conductor having a single solid wire instead of strands of fine wire twisted together.
solid state
Pertaining to circuits where signals pass through solid semiconductor material such as transistors and diodes as opposed to vacuum tubes where signals pass through a vacuum.
sonar
Acronym for "sound navigation and ranging." A system using reflected sound waves to determine the position of some target.
sonic
Pertaining to sound.
sound wave
Pressure waves propagated through air or other plastic media. Sound waves are generally audible to the human ear if the frequency is between approximately 20 and 20,000 vibrations per second. (hertz)
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[align=left]source
Device that provides signal power or energy to a load.
source follower
FET amplifier in which signal is applied between gate and drain with output taken between source and drain. Also called "common drain."
source impedance
Impedance through which output current is taken from a source.
south pole
Pole of a magnet into which magnetic lines of force are assumed to enter.
spark
Momentary discharge of electrical energy due to ionization of air or other dielectric material separating two charges.
SPDT
Single pole double throw.
speaker
Also called "loudspeaker." Transducer that converts electrical energy into mechanical energy at audio frequencies.
spectrum
Arrangement or display of light or other forms of electromagnetic radiation separated according to wavelength, energy or some other property.
spectrum analyzer
Instrument used to display the frequency domain of a waveform plotting amplitude against frequency.
speed-up capacitor
Capacitor added to the base circuit of a BJT switching circuit to improve the switching time of the device.
SPST
Abbreviation for "single pole single throw."
square wave
Wave that alternates between two fixed values for an equal amount of time.
static electricity
Stationary electric charges.
static reverse current
Reverse current through a zener diode when the reverse voltage across the diode is less than the zener voltage rating of the device.
stator
Stationary part of some rotary device such as a variable capacitor.
step-down transformer
Transformer in which the output AC voltage is less than the input AC voltage.
step-up transformer
Transformer in which the output AC voltage is greater than the input AC voltage.
stereo sound
System in which reproduced sound is delivered through two or more channels to give a sense of direction to the source.
stop band
Range of frequencies outside the pass band of a tuned amplifier.
storage time
In a BJT switching circuit, it is the time required for collector current to drop from 100% to 90% of its maximum value.
stranded conductor
Conductor composed of a group of strands of wire twisted together.
stray capacitance
Undesirable capacitance that exists between two conductors such as two leads or one lead and a ****l chassis.
subassembly
Components contained in a unit for convenience in assembling or servicing equipment.
subatomic
Particles such as electrons, protons and neutrons that are smaller than atoms.
substrate
Mechanical insulating support upon which a device is fabricated.
summing amplifier
An op-amp circuit whose output is proportional to the sum of its instantaneous voltages.
superconductor
****l such as lead or niobium that, when cooled to within a few degrees of absolute zero, can conduct current with no resistance.
super heterodyne receiver
Radio receiver that converts all radio frequencies to a fixed intermediate frequency to maximize gain and bandwidth before demodulation.
super high frequency
(SHF) Frequency band between 3 GHz and 30 GHz. So designated by Federal Communications Commission (FCC).
superposition theorem
Theorem designed to simplify networks containing two or more sources. It states that in a network containing more than one source, the current at any one point is equal to the algebraic sum of the currents produced by each source acting separately.
supply voltage
Voltage provided by a power source.
surface leakage current
Diode reverse current that passes along the surface of the semiconductor materials.
surge current
High charging current that flows into a power supply filter capacitor as the power is first turned on.
sweep generator
Test instrument designed to produce a voltage that continuously varies in frequency over a band of frequencies. Used as a source to display frequency response of a circuit on an oscilloscope.
switch
Electrical device having two states, on (closed) or off (open). Ideally having zero impedance when closed and infinite impedance when open.
switching transistor
transistor designed to change rapidly between saturation and cut-off.
synchronization
Also called sync. Precise matching of two waves or functions.
synchronous
Two or more signals in step or in phase.
sync pulse
Pulse used as a reference for synchronization.
system
Combination of several pieces of equipment to perform in a particular manner.
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T
tank circuit
Parallel resonant circuit containing only a coil and a capacitor. Both the coil and capacitor store electrical energy for part of each cycle.
tantalum capacitor
Electrolytic capacitor having a tantalum foil anode. Able to have a large capacity in a small package.
tap
Electrical connection to some point other than at the ends of a resistor or inductor.
tapered
Nonunifrom distribution of resistance per unit length throughout the element of a potentiometer.
telegraphy
Communication between two points by sending and receiving a series of current pulses either through wire or by radio.
telemetry
Transmission of instrument readings to a remote ******** either by wire or by radio.
telephone
Apparatus designed to convert sound waves into electrical waves which are sent to and reproduced data distant point.
telephone line
Wires existing between subscribers and central stations in a telephone system.
telephony
Telecommunications system involving the transmission of speech information, allowing two or more persons to communicate verbally.
television
System that converts both audio and visual information into corresponding electrical signals which are then transmitted through wires or by radio waves to a receiver which reproduces the original information.
telex
Teletypewriter exchange service.
temperature coefficient of frequency
Rate at which frequency changes with temperature.
tera
(T) Metric prefix that represents 1012.
terminal
Point at which electrical connections are made.
tesla
(T) Unit of magnetic flux density. (1 tesla = 1 Wb/m2).
test
Sequence of operations intended to verify the correct operation or malfunctioning of a piece of equipment or system.
thermal relay
Relay activated by a heating element.
thermal runaway
Problem that can develop in an amplifier when an increase in temperature causes an increase in collector current. The increase in collector current causes a further increase in temperature and so on. Unless the circuit is designed to prevent this condition, the device can be driven into saturation.
thermal stability
The ability of a circuit to maintain stable characteristics in spite of increased temperature.
thermistor
Temperature sensitive semiconductor that has a negative temperature coefficient of resistance. As temperature increases, resistance decreases.
thermocouple
Temperature transducer consisting of two dissimilar ****ls welded together at one end to form a junction that when heated will generate a voltage.
thermometry
Relating to the measuring of temperature.
thermostat
Device that opens or closes a circuit in response to changes in temperature.
Thevenin’s theorem
Theorem that replaces any complex network with a single voltage source in series with a single resistance.
thick-film capacitor
Capacitor consisting of two thick-film layers of conductive film separated by a deposited thick-layer dielectric film.
thick film resistor
Fixed value resistor consisting of thick-film resistive element made from ****l particles and glass powder.
thin film capacitor
Capacitor in which both the electrodes and the dielectric are deposited in layers on a substrate.
thin film detector
(TFD) A temperature detector containing a thin layer of platinum and used for precise temperature readings.
three phase supply
AC supply that consists of three AC voltages 120° out of phase with each other.
threshold
Minimum point at which an effect is produced or detected.
threshold voltage
For an enhancement MOSFET, the minimum gate source voltage required for conduction of source drain current.
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thyristor
A term used to classify all four layer semiconductor devices. SCRs and triacs are examples of thyristors.
time constant
(t) Time required for a capacitor in an RC circuit to charge to 63% of the remaining potential across the circuit. Also time required for current to reach 63% of maximum value in an RL circuit. Time constant of an RC circuit is the product of R and C. Time constant of an RL circuit is equal to inductance divided by resistance.
time division multiplexing
(TDM) Transmission of two or more signals on the same path, but at different times.
time-domain analysis
A method of representing a waveform by plotting amplitude over time.
toggle switch
Spring loaded switch that is put in one of two positions either on or off.
tolerance
Permissible deviation from a specified value normally expressed as a percentage.
TO package
Cylindrical, ****l can type of package of some semiconductor components.
toroidal coil
Coil wound on a doughnut shaped core.
transconductance
Also called mutual conductance. Ratio of a change in output current to the change in input voltage that caused it.
transducer
Device that converts energy from one form to another.
transformer
Inductor with two or more windings. Through mutual inductance, current in one winding called a primary will induce current into the other windings called secondaries.
transformer coupling
Also called inductive coupling. Coupling of two circuits by means of mutual inductance provided by a transformer.
transistor
Term derived from "transfer resistor." Semiconductor device that can be used as an amplifier or as an electronic switch.
transmission
Sending of information.
transmission line
Conducting line used to transmit signal energy between two points.
transmitter
Equipment used to achieve transmission.
triac
Bidirectional gate controlled thyristor similar to an SCR, but capable of conducting in both directions. Provides full wave control of AC power.
triangular wave
A repeating wave that has equal positive going and negative going ramps. The ramps have linear rates of change with time.
trigger
Pulse used to initiate a circuit action.
triggering
Initiation of an action in a circuit which then functions for a predetermined time. Example: The duration of one sweep in a cathode ray tube.
trimmer
Small value variable capacitor, resistor or inductor used to fine tune a larger value.
trivalent element
One having three valence electrons. Used as an impurity in semiconductor material to produce p-type material. Most commonly used trivalent elements are: Aluminum, Gallium and Boron.
troubleshooting
Systematic approach to locating the cause of a fault in an electronic circuit or system.
tuned circuit
Circuit that can have its component values adjusted so that it responds to one selected frequency and rejects all others.
tunnel diode
Heavily doped junction diode that has negative resistance in the forward direction of its operating range.
turn-off time
Sum of storage time and fall time.
turn-on time
Sum of delay time and rise time.
turns ratio
Ratio of the number of turns in the secondary winding of a transformer to the number of turns in the primary winding.
two phase
Two repeating waveforms having a phase difference of 90°
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U
UHF
Abbreviation for "ultra high frequency.
uncharged
Material having atoms with the same number of electrons in orbit as the number of protons in the nucleus. Having no electrical charge.
unijunction transistor
Three terminal device that acts as a diode with its own internal voltage divider biasing circuit.
unity gain frequency
Frequency of operation for a device where the gain of the component drops to unity.
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V
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 ****l
The outermost electron ****l for a given atom. The number of electrons in this ****l 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 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.
voltage source
Circuit or device that supplies voltage to a load.
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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W
watt
Unit of electrical power required to do work at the rate of one joule per second. One watt of power is expended when one ampere of direct current flows through a resistance of one ohm. In an AC circuit, true power is the product of effective volts and effective amperes, multiplied by the power factor.
wattage rating
Maximum power a device can safely handle continuously.
watt-hour
Unit of electrical work, equal to a power of one watt being absorbed for one hour.
wattmeter
Instrument used to measure electric power in watts.
wave
Electric, electromagnetic, acoustic, mechanical or other form whose physical activity rises and falls or advances and retreats periodically as it travels through some medium.
waveform
Shape of a wave.
waveguide
Rectangular or circular pipe used to guide electromagnetic waves at micro frequencies.
wavelength
(l) Distance between two points of corresponding phase and is equal to waveform velocity divided by frequency.
weber
(Wb) Unit of magnetic flux. One weber is the amount of flux that when linked with a single turn of wire for an interval of one second will induce an electromotive force of one volt.
wien-bridge oscillator
Oscillator that uses an RC low-pass filter and an RC high-pass filter to set the frequncy of oscillations.
wet cell
Secondary cell using a liquid as an electrolyte.
wetting
Term used in soldering to describe the condition that occurs when the ****ls being soldered are hot enough to melt the solder so it flowes over the surface.
wheatstone bridge
Four arm bridge circuit used to measure resistance, inductance or capacitance.
wideband amplifier
Also called "broadband amplifier." Amplifier with a flat response over a wide range of frequencies.
winding
One or more turns of a conductor wound in the form of a coil.
wire
Single solid or stranded group of conductors having a low resistance to current flow. Used to make connections between circuits or points in a circuit.
wire gauge
American wire gauge (AWG) is a system of numerical designations of wire diameters.
wireless
Term describing radio communication that requires no wired between two communicating points.
wirewound resistor
Resistor in which the resistive element is a length of high resistance wire or ribbon usually nichrome wound onto an insulating form.
wire wrapping
Method of making a connection by wrapping wire around a rectangular pin.
woofer
Large loudspeaker designed primarily to reproduce low frequency audio signals.
work
Work is done any time energy is transformed from one type to another. The amount of work done is dependent on the amount of energy transformed.
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X
X
Symbol for reactance.
X axis
Horizontal axis.
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Y
Y
Symbol for admittance.
Y axis
Vertical axis.
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Z
Z axis
Axis perpendicular to both X and Y axes.
zener diode
Semiconductor diode in which reverse breakdown voltage current causes the diode to develop a constant voltage. Used as a clamp for voltage regulation.
zeroing
Calibrating a meter so that it shows a value of zero when zero is being measured
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جزاكى خيرا اختى الفاضلة
مصطلحات جميلة ومفيدة حقا
انا بدخل عالمنتدى كتير لكن نادرا ما بعطى تعليقى على شىء ......... كتير مشغولة
لكن عن جد انا بحب مواضيعك وحواراتك انتى وأحلام وسويت وغيركم
مشكورة
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[align=center]اختي العزيزة
في البداية اهلا وسهلا بك.........اعتقد ان اسمك نور ......صحيح؟؟؟؟؟؟؟؟
لا تتصوري كم اسعدني ردك وتعليقك.....واتمنى ان يتوفر لديك وقت لنبقى دائما على اتصال وتعبري لنا عن آرائك في مواضيعنا في المنتدى....وهذا امر يسعد الجميع ....ونتمنى ان تشاركينا ايضا في مواضعيك
وانا متأكدة ان احلام وسويتي ستكونان سعيدتين ايضا......فسويتي تسعد كثيرا كلما انضمت فتاة الى المنتدى...فهي لديها خطط شريرة لاحتلال المنتدى من قبل الفتيات............
اهلا وسهلا بك مرة اخرى
واشكرك على المرور[/align]
