Glossary
A searchable reference for basic Technological Education design, electrical, measurement, motion, and unit vocabulary.
Use this glossary for terms and units that appear across the course notes, slides, assignments, and classroom examples.
Glossary category
A36 terms
A/D converter
A device that converts analog input signals to digital output.
A device that converts analog input signals to digital output. [1]
Category:
AC beta
AC effective resistance
Also called: Re
The resistance of a coil for higher-frequency alternating current.
The resistance of a coil for higher-frequency alternating current. The value of Re is more than the DC resistance of the coil because it includes the losses associated with high-frequency alternating current in a coil. These losses include skin effect, eddy currents, and hysteresis losses. [1]
Category:
AC equivalent circuit
AC load line
A graph that shows all the possible values of IC and VCE when a transistor amplifier is driven by an AC signal.
A graph that shows all the possible values of IC and VCE when a transistor amplifier is driven by an AC signal. [1]
Category:
AC load power
AC resistance of a diode
Acceleration
Acceleration is the rate of change of velocity with time and is a vector.
Acceleration is the rate of change of velocity with time. It is a vector, so a change in speed, direction, or both is acceleration. In calculus, acceleration is the derivative of velocity with respect to time. Because velocity is the derivative of position or displacement with respect to time, acceleration is the second derivative of position or displacement with respect to time. Common units include metres per second squared (m/s²) and feet per second squared (ft/s²).
Category:
Active component
Active filter
Active region
The region of operation where the collector of a transistor acts like a current source.
The region of operation where the collector of a transistor acts like a current source. [1]
Category:
Acute angle
Admittance
Air gap
Alkaline cell or battery
Alternating current
Alternation
Amp-clamp probe
A meter that can measure AC currents, generally from the 60-Hz AC power line, without breaking open the circuit.
A meter that can measure AC currents, generally from the 60-Hz AC power line, without breaking open the circuit. The probe of the meter is actually a clamp that fits around the current-carrying conductor. [1]
Category:
Ampere
Also called: A, amp, amps
The ampere (A) is the SI unit of electric current.
The ampere, symbol A, is the SI unit used to measure electric current. In basic circuit work, current values are stated in amperes or amps.
Category:
Ampere turns/meter
Ampere-hour (A·h) rating
A common rating for batteries that indicates how much load current a battery can supply over a specified discharge time.
A common rating for batteries that indicates how much load current a battery can supply over a specified discharge time. For example, a battery with a 100-A.h rating can deliver 1 A for 100 h or 2 A [1]
Category:
Ampere-turn
Also called: A·t
Unit of magnetizing force equal to 1 A × 1 turn.
Unit of magnetizing force equal to 1 A × 1 turn. [1]
Category:
Analog multimeter
A test instrument that is used to make voltage, current, and resistance measurements.
A test instrument that is used to make voltage, current, and resistance measurements. An analog multimeter uses a moving pointer and a printed scale to display the value of the measured quantity. [1]
Category:
Antiresonance
Apparent power
Arctangent
Armature
Asymmetrical JFET
Atom
Atomic number
Attenuation
A term that refers to a reduction in signal amplitude.
A term that refers to a reduction in signal amplitude. [1]
Category:
Audio frequency
Autotransformer
Avalanche
The effect that causes a sharp increase in reverse current, IR, when the reverse-bias voltage across a diode becomes excessive.
The effect that causes a sharp increase in reverse current, IR, when the reverse-bias voltage across a diode becomes excessive. [1]
Category:
B21 terms
B-H magnetization curve
A graph of field intensity H versus flux density B.
A graph of field intensity H versus flux density B. [1]
Category:
Back-offohmmeter scale
Balanced bridge
A circuit consisting of two series strings in parallel.
A circuit consisting of two series strings in parallel. The balanced condition occurs when the voltage ratio in each series string is identical. The output from the bridge is taken between the centers of each series string. When the voltage ratios in each series string are identical, the output voltage is zero and the bridge circuit is said to be balanced. [1]
Category:
Band-pass filter
Band-stop filter
Bandwidth
A range of frequencies that has a resonant effect in LC circuits.
A range of frequencies that has a resonant effect in LC circuits. [1]
Category:
Bank
Banks in series
Parallel resistor banks that are connected in series with each other.
Parallel resistor banks that are connected in series with each other. [1]
Category:
Barrier potential
Also called: VB
The potential difference at the p-n junction of a diode.
The potential difference at the p-n junction of a diode. VB exists between the wall of positive and negative ions that are created as a result of free electrons diffusing from the n-side of the diode to the p-side. [1]
Category:
Base
A thin and very lightly doped region in a transistor.
A thin and very lightly doped region in a transistor. The base is sandwiched between the emitter and collector regions. [1]
Category:
Battery
Group of cells connected in series or parallel.
Group of cells connected in series or parallel. [1]
Category:
Bilateral components
Bleeder current
Branch
Breakdown region
The region of transistor operation where a large undesired collector current flows as a result of the collector-base diode breaking down due to excessive reverse-bias voltage.
The region of transistor operation where a large undesired collector current flows as a result of the collector-base diode breaking down due to excessive reverse-bias voltage. [1]
Category:
Breakdown voltage
Brushes
Bulk resistance
Also called: rB
The resistance of the p and n materials in a diode.
The resistance of the p and n materials in a diode. [1]
Category:
C73 terms
Calorie
Amount of heat energy needed to raise the temperature of one gram of water by 18C.
Amount of heat energy needed to raise the temperature of one gram of water by 18C. [1]
Category:
Capacitance
Capacitive reactance
Also called: XC
A measure of a capacitor’s opposition to the flow of alternating current.
A measure of a capacitor’s opposition to the flow of alternating current. XC is measured in 2 fC XC 5 1 IC. XC applies only to sine-wave AC circuits. [1]
Category:
Capacitive voltage divider
A voltage divider that consists of series-connected capacitors.
A voltage divider that consists of series-connected capacitors. The amount of voltage across each capacitor is inversely proportional to its capacitance value. [1]
Category:
Capacitor
Carbon-composition resistors
Resistors made of finely divided carbon or graphite mixed with a powdered insulating material.
Resistors made of finely divided carbon or graphite mixed with a powdered insulating material. [1]
Category:
Carbon-film resistors
Resistors made by depositing a thin layer of carbon on an insulated substrate.
Resistors made by depositing a thin layer of carbon on an insulated substrate. The carbon film is cut in the form of a spiral. [1]
Category:
Celsius scale
Also called: 8C
Temperature scale that uses 0° for the freezing point of water and 100° for the boiling point.
Temperature scale that uses 0° for the freezing point of water and 100° for the boiling point. Formerly called centigrade. [1]
Category:
Ceramic
Cgs
Channel
The area or conducting region between the drain and source terminals of an FET.
The area or conducting region between the drain and source terminals of an FET. The channel can be made of either n-type or p-type semiconductor material. [1]
Category:
Charging
- The effect of increasing the amount of charge stored in a capacitor.
Category:
Charging current
The current that flows to and from the plates of a capacitor as the charge stored by the dielectric increases.
The current that flows to and from the plates of a capacitor as the charge stored by the dielectric increases. [1]
Category:
Chassis ground
Choke
Inductance with high XL compared with the R of the circuit.
Inductance with high XL compared with the R of the circuit. [1]
Category:
Circuit breaker
Circular mil
Also called: cmil
Cross-sectional area of round wire with diameter of 1 mil or 0.001 in.
Cross-sectional area of round wire with diameter of 1 mil or 0.001 in. [1]
Category:
Class A amplifier
Class B amplifier
Class B push-pull amplifier
A class B amplifier that uses two transistors to reproduce the full AC cycle of input votlage.
A class B amplifier that uses two transistors to reproduce the full AC cycle of input votlage. Each transistor conducts on opposite half-cycles of the input voltage. [1]
Category:
Class C amplifier
Closed-loop cutofffrequency
Also called: fCL
The frequency at which the closed-loop voltage gain decreases to 70.7% of its maximum value.
The frequency at which the closed-loop voltage gain decreases to 70.7% of its maximum value. [1]
Category:
Closed-loop voltage gain
Also called: ACL
The voltage gain of an amplifier with negative feedback.
The voltage gain of an amplifier with negative feedback. [1]
Category:
Coaxial cable
Coding of capacitors
Coefficient of coupling
Coil
Collector
A large, moderately doped region in a transistor.
A large, moderately doped region in a transistor. The collector is the largest of all three transistor regions because it dissipates the most heat. [1]
Category:
Color code
System in which colors are used to indicate values in resistors.
System in which colors are used to indicate values in resistors. [1]
Category:
Common-base amplifier
A transistor amplifier that has its input applied to the emitter and its output taken from the collector.
A transistor amplifier that has its input applied to the emitter and its output taken from the collector. The common-base amplifier provides a high voltage and power gain but its current gain is less than 1. [1]
Category:
Common-collector amplifier
A transistor amplifier that has its input applied to the base and its output taken from the emitter.
A transistor amplifier that has its input applied to the base and its output taken from the emitter. The common-collector amplifier provides a high current and power gain but its voltage gain is less than 1. [1]
Category:
Common-drain amplifier
Common-emitter amplifier
A transistor amplifier that has its input applied to the base and its output taken from the collector.
A transistor amplifier that has its input applied to the base and its output taken from the collector. The common-emitter amplifier provides a high voltage and current gain and a very high power gain. [1]
Category:
Common-gate amplifier
Common-mode input
Common-mode rejection ratio
Also called: CMRR
The ratio of differential voltage gain, Ad, to common mode voltage gain, ACM.
The ratio of differential voltage gain, Ad, to common mode voltage gain, ACM. CMRR is usually specified in decibels. [1]
Category:
Common-mode voltage gain
Also called: ACM
The voltage gain of a differential amplifier for a common- mode signal.
The voltage gain of a differential amplifier for a common- mode signal. [1]
Category:
Common-source amplifier
Commutator
Comparator
Complex number
Compound
Conductance
Also called: G
Ability to conduct current.
Ability to conduct current. It is the reciprocal of resistance The unit is the siemens (S). [1]
Category:
Conductor
Any material that allows the free movement of electric charges, such as electrons, to provide an electric current.
Any material that allows the free movement of electric charges, such as electrons, to provide an electric current. [1]
Category:
Constant-current source
A generator whose internal resistance is very high compared with the load resistance.
A generator whose internal resistance is very high compared with the load resistance. Since its internal resistance is so high, it can supply a constant current to a load whose resistance value varies over a wide range. [1]
Category:
Constant-voltage source
A generator whose internal resistance is very low compared with the load resistance.
A generator whose internal resistance is very low compared with the load resistance. Since its internal resistance is so low, it can supply a constant voltage to a load whose resistance value varies over a wide range. [1]
Category:
Continuity
Continuity testing
A resistance measurement that determines whether there is zero ohms of resistance (approximately) between two points, such as across the ends of a wire conductor.
A resistance measurement that determines whether there is zero ohms of resistance (approximately) between two points, such as across the ends of a wire conductor. [1]
Category:
Conventional current
The direction of current flow associated with positive charges in motion.
The direction of current flow associated with positive charges in motion. The current flow direction is from a positive to a negative potential, which is in the opposite direction of electron flow. [1]
Category:
Corona effect
Effect of ionization of air around a point at high potential.
Effect of ionization of air around a point at high potential. [1]
Category:
Cosine
A trigonometric function of an angle, equal to the ratio of the adjacent side to the hypotenuse in a right triangle.
A trigonometric function of an angle, equal to the ratio of the adjacent side to the hypotenuse in a right triangle. [1]
Category:
Cosine wave
Coulomb
Also called: C
Unit of electric charge.
Unit of electric charge. 1 C 5 6.25 × 1018 electrons. [1]
Category:
Counter emf
Covalent bond
Pairing of atoms with electron valence of 64.
Pairing of atoms with electron valence of 64. [1]
Category:
Covalent bonding
The sharing of valence electrons between neighboring atoms in a silicon crystal or other crystalline structure.
The sharing of valence electrons between neighboring atoms in a silicon crystal or other crystalline structure. [1]
Category:
Cps
Crossover distortion
The distortion that occurs in a class B push-pull amplifier when the transistors are biased right at cutoff.
The distortion that occurs in a class B push-pull amplifier when the transistors are biased right at cutoff. When the input voltage crosses through zero both transistors in the push-pull amplifier are offand the output voltage cannot follow the input voltage. [1]
Category:
CRT
Cathode-ray tube.
Cathode-ray tube. A device that converts electric signals to a visual display on a fluorescent screen. [1]
Category:
Crystal filter
Curie temperature
The temperature at which a magnetic material loses its ferromagnetic properties.
The temperature at which a magnetic material loses its ferromagnetic properties. [1]
Category:
Current
Also called: Electric Current, I
Current is the rate at which electric charge flows through a circuit.
Electric current is the rate at which electric charge flows through a circuit. The common quantity symbol is I and the SI unit is the ampere (A). More current means more electric charge is moving past a point each second.
Category:
Current divider
A parallel circuit to provide branch I less than the main-line current.
A parallel circuit to provide branch I less than the main-line current. [1]
Category:
Current gain
Also called: A i
The ratio of output current to input current in a transistor amplifier.
The ratio of output current to input current in a transistor amplifier. [1]
Category:
Current source
Current-source region
The region of operation in which the drain of a JFET acts as a current source.
The region of operation in which the drain of a JFET acts as a current source. The current-source region of operation exists when VDS. VP. [1]
Category:
Cutoff
The region of transistor operation where the collector current, IC, is zero.
The region of transistor operation where the collector current, IC, is zero. [1]
Category:
Cutofffrequency
The frequency at which the attenuation of a filter reduces the output amplitude to 70.7% of its value in the passband.
The frequency at which the attenuation of a filter reduces the output amplitude to 70.7% of its value in the passband. [1]
Category:
Cycle
One complete set of values for a repetitive waveform.
One complete set of values for a repetitive waveform. [1]
Category:
D40 terms
Damping
DB
DC alpha
DC beta
DC input power
Also called: PCC
The amount of DC power dissipated by a transistor amplifier.
The amount of DC power dissipated by a transistor amplifier. [1]
Category:
DC load line
A graph that shows all of the possible values of IC and VCE for a given transistor amplifier.
A graph that shows all of the possible values of IC and VCE for a given transistor amplifier. The endpoints of the DC load line are IC(sat) and VCE(off) which represent the values of IC and VCE when the transistor is in saturation and cutoff. [1]
Category:
Decade
Decade resistance box
A unit for providing any resistance within a wide range of values.
A unit for providing any resistance within a wide range of values. [1]
Category:
Decimal notation
Numbers that are written in standard form without using powers of 10 notation.
Numbers that are written in standard form without using powers of 10 notation. [1]
Category:
Degaussing
Delta (D) network
Depletion mode
The mode of operation for a MOSFET in which the polarity of VGS causes the drain current to be reduced as the channel becomes depleted of available charge carriers.
The mode of operation for a MOSFET in which the polarity of VGS causes the drain current to be reduced as the channel becomes depleted of available charge carriers. [1]
Category:
Depletion zone
Derating curve
Derating factor
The amount that the power rating of a transistor must be reduced for each degree Celsius above 25°C.
The amount that the power rating of a transistor must be reduced for each degree Celsius above 25°C. The derating factor is specified in W/°C. [1]
Category:
Diac
A bidirectional semiconductor device that conducts when the voltage across its terminals reaches the breakover voltage 6VBO.
A bidirectional semiconductor device that conducts when the voltage across its terminals reaches the breakover voltage 6VBO. Once conducting the voltage across the diac drops to a very low value. [1]
Category:
Diamagnetic
Dielectric absorption
The inability of a capacitor to completely discharge to zero.
The inability of a capacitor to completely discharge to zero. Dielectric absorption is sometimes called battery action or capacitor memory. [1]
Category:
Dielectric constant
Ability to concentrate the electric field in a dielectric.
Ability to concentrate the electric field in a dielectric. [1]
Category:
Dielectric material
Dielectric strength
The ability of a dielectric to withstand a potential difference without internal arcing.
The ability of a dielectric to withstand a potential difference without internal arcing. [1]
Category:
Differential input voltage
Differential voltage gain
Also called: Ad
The ratio of output voltage, Vout, to differential input voltage, Vid.
The ratio of output voltage, Vout, to differential input voltage, Vid. [1]
Category:
Differentiator
An RC circuit with a short time constant for pulses across R.
An RC circuit with a short time constant for pulses across R. [1]
Category:
Digital multimeter
Also called: DMM
A popular test instrument that is used to measure voltage, current, and resistance.
A popular test instrument that is used to measure voltage, current, and resistance. [1]
Category:
Diode
Diode bias
A form of biasing for class B push- pull amplifiers that uses diodes to provide a slight amount of forward bias for the base-emitter junctions of each transistor.
A form of biasing for class B push- pull amplifiers that uses diodes to provide a slight amount of forward bias for the base-emitter junctions of each transistor. [1]
Category:
Direct current
Discharge current
The current that flows to and from the plates of a capacitor as the charge stored by the dielectric decreases.
The current that flows to and from the plates of a capacitor as the charge stored by the dielectric decreases. [1]
Category:
Discharging
- The action of neutralizing the charge stored in a capacitor by connecting a conducting path across the capacitor leads.
Category:
Displacement
Displacement is the change in position from a starting point to an ending point, including direction.
Displacement is a vector that describes the change in position from a starting point to an ending point. It has both magnitude and direction and does not depend on the total path travelled.
Category:
Distance
Doping
The process of adding impurity atoms to a pure semiconductor material such as silicon.
The process of adding impurity atoms to a pure semiconductor material such as silicon. [1]
Category:
Double-subscript notation
A notational system that identifies the points in the circuit where a voltage measurement is to be taken, i.e.; VAG.
A notational system that identifies the points in the circuit where a voltage measurement is to be taken, i.e.; VAG. The first letter in the subscript indicates the point in the circuit where the measurement is to be taken whereas the second letter indicates the point of reference. [1]
Category:
DPDT
DPST
Drain
Dynamometer
E26 terms
Earth ground
A direct connection to the earth usually made by driving copper rods into the earth and then connecting the ground wire of an electrical system to this point.
A direct connection to the earth usually made by driving copper rods into the earth and then connecting the ground wire of an electrical system to this point. The earth ground connection can serve as a common return path for the current in a circuit. [1]
Category:
Eddy current
Circulating current induced in the iron core of an inductor by AC variations of magnetic flux.
Circulating current induced in the iron core of an inductor by AC variations of magnetic flux. [1]
Category:
Effective value
For sine-wave AC waveform, 0.707 of peak value.
For sine-wave AC waveform, 0.707 of peak value. Corresponds to heating effect of same DC value. Also called rms value. [1]
Category:
Efficiency
EIA
Electric field
The invisible lines of force between opposite electric charges.
The invisible lines of force between opposite electric charges. [1]
Category:
Electricity
Dynamic electricity is the effect of voltage in producing current in conductors.
Dynamic electricity is the effect of voltage in producing current in conductors. Static electricity is accumulation of charge. [1]
Category:
Electrolytic capacitor
Type with very high C because electrolyte is used to form very thin dielectric.
Type with very high C because electrolyte is used to form very thin dielectric. Must be connected with correct polarity in a circuit. [1]
Category:
Electromagnet
Magnet whose magnetic field is associated with electric current in a coil.
Magnet whose magnetic field is associated with electric current in a coil. [1]
Category:
Electron
Electron flow
Current of negative charges in motion.
Current of negative charges in motion. Direction is from the negative terminal of the voltage source, through the external circuit, and returning to the positive side of the source. Opposite to the direction of conventional current. [1]
Category:
Electron valence
Electron volt
Unit of energy equal to the work done in moving a charge of 1 electron through a potential difference of 1 V.
Unit of energy equal to the work done in moving a charge of 1 electron through a potential difference of 1 V. [1]
Category:
Electron-hole pair
The creation of a free electron and a hole when a valence electron gains enough energy to leave its covalent bond in a silicon crystal.
The creation of a free electron and a hole when a valence electron gains enough energy to leave its covalent bond in a silicon crystal. [1]
Category:
Element
A substance that cannot be decomposed any further by chemical action.
A substance that cannot be decomposed any further by chemical action. [1]
Category:
Emf
Emitter
The most heavily doped region in a transistor.
The most heavily doped region in a transistor. Its job is to inject or emit current carriers into the base region. [1]
Category:
Emitter bypass capacitor
Also called: CE
A capacitor that bypasses the AC signal around the emitter resistor in a transistor amplifier.
A capacitor that bypasses the AC signal around the emitter resistor in a transistor amplifier. [1]
Category:
Emitter follower
Another name for the common-collector amplifier.
Another name for the common-collector amplifier. [1]
Category:
Engineering Design Process
Also called: Design Process, EDP
The engineering design process is an iterative way to identify needs, create solutions, test them, and improve them.
The engineering design process is a flexible, iterative approach to solving problems. A typical cycle identifies the problem and needs, investigates existing information and solutions, develops ideas, creates or prototypes a solution, tests and evaluates it, communicates results, and improves the design. The process can loop backward or repeat whenever new evidence changes what the design needs.
Category:
Engineering notation
A form of powers of 10 notation in which a number is expressed as a number between 1 and 1000 times a power of 10 that is a multiple of 3.
A form of powers of 10 notation in which a number is expressed as a number between 1 and 1000 times a power of 10 that is a multiple of 3. [1]
Category:
Enhancement mode
The mode of operation for a MOSFET in which the polarity of VGS causes the conductivity of the channel to be enhanced, thus increasing the drain current.
The mode of operation for a MOSFET in which the polarity of VGS causes the conductivity of the channel to be enhanced, thus increasing the drain current. [1]
Category:
Equivalent resistance
Also called: REQ
In a parallel circuit this refers to a single resistance that would draw the same amount of current as all the parallel connected branches.
In a parallel circuit this refers to a single resistance that would draw the same amount of current as all the parallel connected branches. [1]
Category:
Equivalent series resistance
Also called: ESR
A resistance in series with an ideal capacitor that collectively represents all of the losses in a capacitor.
A resistance in series with an ideal capacitor that collectively represents all of the losses in a capacitor. Ideally, the ESR of a capacitor should be zero. [1]
Category:
Extrinsic semiconductor
A semiconductor that has been doped with impurity atoms to alter the characteristics of the material, mainly its conductivity.
A semiconductor that has been doped with impurity atoms to alter the characteristics of the material, mainly its conductivity. [1]
Category:
F30 terms
F connector
Fahrenheit scale
Also called: 8F
Temperature scale that uses 32° for the freezing point of water and 212° for the boiling point.
Temperature scale that uses 32° for the freezing point of water and 212° for the boiling point. [1]
Category:
Farad
Also called: F
Unit of capacitance.
Unit of capacitance. Value of one farad stores one coulomb of charge with one volt applied. [1]
Category:
Faraday’s law
For magnetic induction, the generated voltage is proportional to the flux and its rate of change.
For magnetic induction, the generated voltage is proportional to the flux and its rate of change. [1]
Category:
Feet per Second Squared
Also called: ft/s^2, ft/s²
Feet per second squared (ft/s²) is a non-SI unit of acceleration.
Feet per second squared, written ft/s², is a common non-SI unit of acceleration.
Category:
Ferrite
Ferrite core
A type of core that has a high value of flux density, like iron, but is an insulator.
A type of core that has a high value of flux density, like iron, but is an insulator. A ferrite core used in a coil has minimum eddy current losses due to its high resistance. [1]
Category:
Ferromagnetic
Field
Group of lines of force; magnetic or electric field.
Group of lines of force; magnetic or electric field. [1]
Category:
Field effect transistor
Also called: FET
A unipolar device that relies on only one type of charge carrier, either electrons or holes.
A unipolar device that relies on only one type of charge carrier, either electrons or holes. FETs are voltage-controlled devices with an input voltage controlling the output current. [1]
Category:
Field intensity
Field winding
Film capacitor
A capacitor that uses a plastic film for its dielectric.
A capacitor that uses a plastic film for its dielectric. [1]
Category:
Filter
Float charging
A method of charging in which the charger and the battery are always connected to each other for supplying current to the load.
A method of charging in which the charger and the battery are always connected to each other for supplying current to the load. With this method, the charger provides the current for the load and the current necessary to keep the battery fully charged. [1]
Category:
Fluctuating direct current
Flux
Flux density
Flywheel effect
Form factor
Forward blocking current
Forward breakover voltage
Forward-bias
Free electron
Frequency
Frequency multiplier
A tuned class C amplifier that has its LC tank circuit tuned to a harmonic or multiple of the input frequency.
A tuned class C amplifier that has its LC tank circuit tuned to a harmonic or multiple of the input frequency. [1]
Category:
Fuel cell
An electrochemical device that converts the chemicals hydrogen and oxygen into water, and in the process produces electricity.
An electrochemical device that converts the chemicals hydrogen and oxygen into water, and in the process produces electricity. A fuel cell provides a steady DC output voltage that can power motors, lights, or other appliances. Unlike a regular battery, however, a fuel cell constantly has chemicals flowing into it so it never goes dead. [1]
Category:
Full-wave rectifier
A circuit that provides an entirely positive or negative output voltage when an AC input voltage is applied.
A circuit that provides an entirely positive or negative output voltage when an AC input voltage is applied. A full-wave rectifier provides an output for both the positive and negative alternations of the input voltage. [1]
Category:
Funity
The frequency where the open-loop voltage gain, Avol, of an op amp equals 1 or unity.
The frequency where the open-loop voltage gain, Avol, of an op amp equals 1 or unity. [1]
Category:
G12 terms
Galvanic cell
Galvanometer
Ganged capacitors
Gate
Gate-source cutoffvoltage
Gauss
Unit of flux density in cgs system equal to one magnetic line of force per square centimeter.
Unit of flux density in cgs system equal to one magnetic line of force per square centimeter. [1]
Category:
Generator
Germanium
Also called: Ge
Semiconductor element used for transistors and diodes.
Semiconductor element used for transistors and diodes. [1]
Category:
Giga
Gilbert
Also called: Gb
Unit of magnetomotive force in cgs system.
Unit of magnetomotive force in cgs system. One gilbert equals 0.794 ampere- turn. [1]
Category:
Graph cycle
A 10:1 range of values on logarithmic graph paper.
A 10:1 range of values on logarithmic graph paper. [1]
Category:
Ground
Common return to earth for AC power lines.
Common return to earth for AC power lines. Chassis ground in electronic equipment is the common return to one side of the internal power supply. [1]
Category:
H16 terms
Half-power points
Half-wave rectifier
A circuit that provides an entirely positive or negative output voltage when an AC input voltage is applied.
A circuit that provides an entirely positive or negative output voltage when an AC input voltage is applied. A half-wave rectifier provides an output for either the positive or negative alternation of the input voltage but not both. [1]
Category:
Hall effect
Harmonic frequency
Henry
Unit of inductance.
Unit of inductance. Current change of one ampere per second induces one volt across an inductance of one henry. [1]
Category:
Hertz
High-pass filter
A filter that allows the higher- frequency components of the applied voltage to develop appreciable output voltage while at the same time attenuating or eliminating the lower-frequency components.
A filter that allows the higher- frequency components of the applied voltage to develop appreciable output voltage while at the same time attenuating or eliminating the lower-frequency components. [1]
Category:
Holding current
Also called: IH
Hole
The absence of a valence electron in a covalent bond structure.
The absence of a valence electron in a covalent bond structure. The hole exhibits a positive charge. [1]
Category:
Hole current
Motion of hole charges.
Motion of hole charges. Direction is the same as that of conventional current, opposite from electron flow. [1]
Category:
Horsepower
Hot resistance
Hydrometer
Hypotenuse
Side of a right triangle opposite the 90° angle.
Side of a right triangle opposite the 90° angle. [1]
Category:
I23 terms
IGFET
Insulated gate field effect transistor.
Insulated gate field effect transistor. Another name for a MOSFET. [1]
Category:
Imaginary number
Value at 90°, indicated by j operator, as in the form jA.
Value at 90°, indicated by j operator, as in the form jA. [1]
Category:
Impedance
Also called: Z
The total opposition to the flow of current in a sine-wave AC circuit.
The total opposition to the flow of current in a sine-wave AC circuit. In an RC circuit, the impedance, Z, takes into account the 90° phase relation between XC and R. Impedance, Z, is measured in ohms. [1]
Category:
Impedance matching
Inductance
Also called: L
Ability to produce induced voltage when cut by magnetic flux.
Ability to produce induced voltage when cut by magnetic flux. Unit of inductance is the henry (H). [1]
Category:
Induction
Ability to generate V or I without physical contact.
Ability to generate V or I without physical contact. Electromagnetic induction by magnetic field; electrostatic induction by electric field. [1]
Category:
Inductive reactance
Also called: X L
A measure of an inductor’s opposition to the flow of alternating current.
A measure of an inductor’s opposition to the flow of alternating current. XL is measured in ohms and is calculated as [1]
Category:
Inductor
Input bias current
Input impedance
Input offset current
Insulator
A material that does not allow current to flow when voltage is applied, because of its high resistance.
A material that does not allow current to flow when voltage is applied, because of its high resistance. [1]
Category:
Integrator
An RC circuit with a long time constant.
An RC circuit with a long time constant. Voltage output across C. [1]
Category:
Interbase resistance
Also called: RBB
The resistance of the n-type silicon bar in a UJT.
The resistance of the n-type silicon bar in a UJT. RBB appears as two resistances, RB1 and RB2. RBB 5 RB1 1 RB2. [1]
Category:
Internal resistance ri
Limits the current supplied by the voltage source to
Limits the current supplied by the voltage source to [1]
Category:
Intrinsic semiconductor
A semiconductor material with only one type of atom.
A semiconductor material with only one type of atom. [1]
Category:
Intrinsic standoffratio
Inverse relation
Same as reciprocal relation.
Same as reciprocal relation. As one variable increases, the other decreases. [1]
Category:
Inversely proportional
The same as a reciprocal relation; as the value in the denominator increases the resultant quotient decreases.
The same as a reciprocal relation; as the value in the denominator increases the resultant quotient decreases. In the formula XC 5 1 2πfC. XC is inversely proportional to both f and C. This means that as f and C increase, XC decreases. [1]
Category:
Ion
Ionization current
J3 terms
J operator
Indicates 90° phase angle, as in j8 V for XL.
Indicates 90° phase angle, as in j8 V for XL. Also, 2j 8 V is at 290° for XC. [1]
Category:
JFET
K7 terms
Keeper
Kelvin (K) scale
Absolute temperature scale, 273° below values on Celsius scale.
Absolute temperature scale, 273° below values on Celsius scale. [1]
Category:
Kilo
Kilometres per Hour
Also called: km/h
Kilometres per hour (km/h) is a common unit of speed and velocity.
Kilometres per hour, written km/h, states how many kilometres are covered in one hour. It is commonly used for road speed in Canada and many other countries. When a direction is included, it can also be used for velocity.
Category:
Kilowatt-hour
A large unit of electrical energy corresponding to 1 kW·1 h.
A large unit of electrical energy corresponding to 1 kW·1 h. [1]
Category:
Kirchhoff ’s current law
Kirchhoff ’s voltage law
Also called: KVL
The algebraic sum of all voltages around any closed path must equal zero.
The algebraic sum of all voltages around any closed path must equal zero. [1]
Category:
L20 terms
Laminations
Thin sheets of steel insulated from one another to reduce eddy-current losses in inductors, motors, etc.
Thin sheets of steel insulated from one another to reduce eddy-current losses in inductors, motors, etc. [1]
Category:
Leakage current
- The current that flows through the dielectric of a capacitor when voltage is applied across the capacitor plates.
- The current that flows through the dielectric of a capacitor when voltage is applied across the capacitor plates. (2) The very small current that flows when a diode is reverse-biased. The leakage current is mainly due to the thermally generated minority carriers that exist in both sections of the diode. [1]
Category:
Leakage flux
Leakage resistance
A resistance in parallel with a capacitor that represents all of the leakage paths through which a capacitor can discharge.
A resistance in parallel with a capacitor that represents all of the leakage paths through which a capacitor can discharge. [1]
Category:
Leclanché cell
Left-hand rule
If the coil is grasped with the fingers of the left hand curled around the coil in the direction of electron flow, the thumb points to the north pole of the coil.
If the coil is grasped with the fingers of the left hand curled around the coil in the direction of electron flow, the thumb points to the north pole of the coil. [1]
Category:
Lenz’s law
Light-emitting diode
Linear amplifier
Any amplifier that produces an output signal that is an exact replica of the input signal.
Any amplifier that produces an output signal that is an exact replica of the input signal. [1]
Category:
Linear component
An electronic component whose current is proportional to the applied voltage.
An electronic component whose current is proportional to the applied voltage. [1]
Category:
Linear proportion
Straight-line graph between two variables.
Straight-line graph between two variables. As one increases, the other increases in direct proportion. [1]
Category:
Linear resistance
A resistance with a constant value of ohms.
A resistance with a constant value of ohms. [1]
Category:
Load
Takes current from the voltage source, resulting in load current.
Takes current from the voltage source, resulting in load current. [1]
Category:
Load currents
The currents drawn by the electronic devices and/or components connected as loads in a loaded voltage divider.
The currents drawn by the electronic devices and/or components connected as loads in a loaded voltage divider. [1]
Category:
Loaded voltage
The voltage at a point in a series voltage divider where a parallel load has been connected.
The voltage at a point in a series voltage divider where a parallel load has been connected. [1]
Category:
Loading effect
Long time constant
A long time constant can arbitrarily be defined as one that is five or more times longer than the pulse width of the applied voltage.
A long time constant can arbitrarily be defined as one that is five or more times longer than the pulse width of the applied voltage. [1]
Category:
Loop equation
Low-pass filter
A filter that allows the lower frequency components of the applied voltage to develop appreciable output voltage while at the same time attenuating or eliminating the higher-frequency components.
A filter that allows the lower frequency components of the applied voltage to develop appreciable output voltage while at the same time attenuating or eliminating the higher-frequency components. [1]
Category:
M32 terms
Magnetic flux
Magnetic pole
Magnetism
Effects of attraction and repulsion by iron and similar materials without the need for an external force.
Effects of attraction and repulsion by iron and similar materials without the need for an external force. Electromagnetism includes the effects of a magnetic field associated with an electric current. [1]
Category:
Magnetomotive force
Also called: mmf
Ability to produce magnetic lines of force.
Ability to produce magnetic lines of force. Measured in units of ampere-turns. [1]
Category:
Magnitude
Value of a quantity regardless of phase angle.
Value of a quantity regardless of phase angle. [1]
Category:
Main line
The pair of leads connecting all of the individual branches in a parallel circuit to the terminals of the applied voltage, VA.
The pair of leads connecting all of the individual branches in a parallel circuit to the terminals of the applied voltage, VA. The main line carries the total current, IT, flowing to and from the terminals of the voltage source. [1]
Category:
Majority current carrier
The dominant type of charge carrier in a doped semiconductor material.
The dominant type of charge carrier in a doped semiconductor material. In an n-type semiconductor free electrons are the majority current carriers whereas in a p-type semiconductor holes are the majority current carriers. [1]
Category:
Make and break
Maximum working voltage rating
Maxwell
Also called: Mx
Unit of magnetic flux equal to one line of force in the magnetic field.
Unit of magnetic flux equal to one line of force in the magnetic field. [1]
Category:
Mega
Mesh
Mesh current
Assumed current in a closed path, without any current division, for application of Kirchhoff’s current law.
Assumed current in a closed path, without any current division, for application of Kirchhoff’s current law. [1]
Category:
Metal-film resistors
Metre
Also called: m, meter
The metre (m) is the SI base unit of length.
The metre, symbol m, is the SI base unit used to measure length. In motion problems it can describe distance or displacement.
Category:
Metres per Second
Also called: m/s
Metres per second (m/s) is a unit of speed and velocity.
Metres per second, written m/s, tells how many metres of distance or displacement are covered each second. It is a common SI unit for both speed and velocity.
Category:
Metres per Second Squared
Also called: m/s^2, m/s²
Metres per second squared (m/s²) is a unit of acceleration.
Metres per second squared, written m/s², is a unit of acceleration. A value of 1 m/s² means velocity changes by 1 metre per second during each second.
Category:
Metric prefixes
Letter symbols used to replace the powers of 10 that are multiples of 3.
Letter symbols used to replace the powers of 10 that are multiples of 3. [1]
Category:
Micro
Microfarad
A small unit of capacitance equal to 1 × 1026 F.
A small unit of capacitance equal to 1 × 1026 F. [1]
Category:
Midpoint bias
A bias point that is centered between cutoffand saturation on the DC load line.
A bias point that is centered between cutoffand saturation on the DC load line. [1]
Category:
Miles per Hour
Also called: mph
Miles per hour (mph) is a common non-SI unit of speed and velocity.
Miles per hour, written mph, states how many miles are covered in one hour. It is common in U.S. customary and some Imperial contexts. When a direction is included, it can also be used for velocity.
Category:
Milli
Millman’s theorem
Minority current carrier
The type of charge carrier that appears sparsely throughout a doped semiconductor material.
The type of charge carrier that appears sparsely throughout a doped semiconductor material. In an n-type semiconductor, holes are the minority current carriers whereas free electrons are the minority current carriers in a p-type semiconductor. [1]
Category:
Mks
Molecules
MOSFET
Metal-oxide-semiconductor field effect transistor.
Metal-oxide-semiconductor field effect transistor. [1]
Category:
Motor
A device that produces mechanical motion from electric energy.
A device that produces mechanical motion from electric energy. [1]
Category:
Motor action
Multiplier resistor
N14 terms
N-type semiconductor
A semiconductor that has been doped with pentavalent impurity atoms.
A semiconductor that has been doped with pentavalent impurity atoms. The result is a large number of free electrons throughout the material. Since the electron is the basic particle of negative charge, the material is called n-type semiconductor material. [1]
Category:
N.I.C.E. Design Process
Also called: N.I.C.E.
N.I.C.E. is a classroom design cycle: Needs & Necessities → Investigate & Inquire → Create & Communicate → Evaluate → repeat.
The N.I.C.E. Design Process is a classroom design cycle used in these resources: Needs & Necessities → Investigate & Inquire → Create & Communicate → Evaluate → repeat. It begins with what the design actually needs to accomplish, uses inquiry and investigation before choosing a solution, makes and communicates the solution, and uses evaluation to return to the needs and improve the next version.
Category:
Nano
Nanofarad
A small unit of capacitance equal to 1 × 1029 F.
A small unit of capacitance equal to 1 × 1029 F. [1]
Category:
NC
Negative feedback
A form of amplifier feedback where the returning signal has a phase that opposes the input signal.
A form of amplifier feedback where the returning signal has a phase that opposes the input signal. [1]
Category:
Negative saturation voltage
Negative temperature coefficient
Also called: NTC
A characteristic of a thermistor indicating that its resistance decreases with an increase in operating temperature.
A characteristic of a thermistor indicating that its resistance decreases with an increase in operating temperature. [1]
Category:
Neutron
Node
Nonlinear resistance
A resistance whose value changes as a result of current producing power dissipation and heat in the resistance.
A resistance whose value changes as a result of current producing power dissipation and heat in the resistance. [1]
Category:
Nonsinusoidal waveform
Any waveform that is not a sine or a cosine wave.
Any waveform that is not a sine or a cosine wave. [1]
Category:
Norton’s theorem
Method of reducing a complicated network to one current source with shunt resistance.
Method of reducing a complicated network to one current source with shunt resistance. [1]
Category:
O14 terms
Obtuse angle
Octave
Oersted
Also called: Oe
Unit of magnetic field intensity; 1
Unit of magnetic field intensity; 1 [1]
Category:
Ohm
Also called: ohms
The ohm (Ω) is the SI unit of electrical resistance.
The ohm, symbol Ω, is the SI unit used to measure electrical resistance. In a simple resistive circuit, 1 ohm of resistance allows 1 ampere of current when 1 volt is applied.
Category:
Ohmic region
Ohms-per-volt rating
Ohm’s law
Open circuit
One that has infinitely high resistance, resulting in zero current.
One that has infinitely high resistance, resulting in zero current. [1]
Category:
Open-circuit voltage
The voltage present across the output terminals of a voltage source when no load is present.
The voltage present across the output terminals of a voltage source when no load is present. [1]
Category:
Open-loop cutofffrequency
Also called: fOL
The frequency at which the open-loop voltage gain of an op amp is down to 70.7% of its maximum value at DC.
The frequency at which the open-loop voltage gain of an op amp is down to 70.7% of its maximum value at DC. [1]
Category:
Open-loop voltage gain
Also called: A VOL
The voltage gain of an op amp without negative feedback.
The voltage gain of an op amp without negative feedback. [1]
Category:
Operational amplifier
Also called: op amp
A high-gain, direct-coupled differential amplifier.
A high-gain, direct-coupled differential amplifier. [1]
Category:
Oscilloscope
P46 terms
P-type semiconductor
A semiconductor that has been doped with trivalent impurity atoms.
A semiconductor that has been doped with trivalent impurity atoms. The result is a large number of holes in the material. Since a hole exhibits a positive charge, the material is called p-type semiconductor material. [1]
Category:
Parallel bank
A combination of parallel- connected branches.
A combination of parallel- connected branches. [1]
Category:
Parallel circuit
One that has two or more branches for separate currents from one voltage source.
One that has two or more branches for separate currents from one voltage source. [1]
Category:
Paramagnetic
Material that can be weakly magnetized in the same direction from the magnetizing force.
Material that can be weakly magnetized in the same direction from the magnetizing force. [1]
Category:
Passive component
PC board
Peak inverse voltage
Also called: PIV
The maximum instantaneous reverse-bias voltage across a diode.
The maximum instantaneous reverse-bias voltage across a diode. [1]
Category:
Peak reverse voltage rating
Also called: VROM
The maximum reverse-bias voltage that can be safely applied between the anode and cathode terminals of an SCR with the gate open.
The maximum reverse-bias voltage that can be safely applied between the anode and cathode terminals of an SCR with the gate open. [1]
Category:
Peak value
Maximum amplitude, in either polarity; 1.414 times rms value for sine- wave V or I.
Maximum amplitude, in either polarity; 1.414 times rms value for sine- wave V or I. [1]
Category:
Peak-to-peak value
Pentavalent atom
Percent efficiency
For an amplifier, this refers to the percentage of DC input power that is converted to useful AC output power.
For an amplifier, this refers to the percentage of DC input power that is converted to useful AC output power. [1]
Category:
Period
Permanent magnet
Permeability
Ability to concentrate magnetic lines of force.
Ability to concentrate magnetic lines of force. [1]
Category:
Phase angle
Phasing dots
Used on transformer windings to identify those leads having the same instantaneous polarity.
Used on transformer windings to identify those leads having the same instantaneous polarity. [1]
Category:
Phasor
Phasor triangle
Pickup current
Pico
Picofarad
A small unit of capacitance equal to 1 × 10212 F.
A small unit of capacitance equal to 1 × 10212 F. [1]
Category:
Pinch-offvoltage
Polar form
Form of complex numbers that gives magnitude and phase angle in the form A/u 8.
Form of complex numbers that gives magnitude and phase angle in the form A/u 8. [1]
Category:
Polarity
Pole
Position
Position describes where an object is relative to a chosen reference point.
Position describes an object's location relative to a chosen reference point or coordinate system. A change in position is displacement.
Category:
Positive saturation voltage
Positive temperature coefficient
Also called: PTC
A characteristic of a thermistor indicating that its resistance increases with an increase in operating temperature.
A characteristic of a thermistor indicating that its resistance increases with an increase in operating temperature. [1]
Category:
Potentiometer
Variable resistor with three terminals connected as a voltage divider.
Variable resistor with three terminals connected as a voltage divider. [1]
Category:
Power
Power amplifier
Power bandwidth
Also called: fmax
The highest undistorted frequency out of an op amp without slew- rate distortion.
The highest undistorted frequency out of an op amp without slew- rate distortion. [1]
Category:
Power factor
Power gain
Also called: AP
The ratio of output power to input power in a transistor amplifier.
The ratio of output power to input power in a transistor amplifier. AP can also be calculated as [1]
Category:
Power supply
Powers of 10
Preferred values
Common values of resistors and capacitors generally available.
Common values of resistors and capacitors generally available. [1]
Category:
Primary winding
Transformer coil connected to the source voltage.
Transformer coil connected to the source voltage. [1]
Category:
Principal node
Printed wiring
Proportional
A mathematical term used to describe the relationship between two quantities.
A mathematical term used to describe the relationship between two quantities. For example, in the formula The term proportional means that if either f or L is doubled XL will double. Similarly, if either f or L is reduced by one-half, XL will be reduced by one-half. In other words, XL will increase or decrease in direct proportion to either f or L. [1]
Category:
Proton
Pulsating DC
Pulse
A sharp rise and decay of voltage or current of a specific peak value for a brief period of time.
A sharp rise and decay of voltage or current of a specific peak value for a brief period of time. [1]
Category:
Q3 terms
Q of a coil
The quality or figure of merit for a coil.
The quality or figure of merit for a coil. More specifically, the Q of a coil can be defined as the ratio of reactive power in the inductance to the real power dissipated in the coil’s resistance. Q 5 XL ri. [1]
Category:
Q point
The values of IC and VCE that exist in a transistor amplifier with no AC signal present.
The values of IC and VCE that exist in a transistor amplifier with no AC signal present. [1]
Category:
Quadrature phase
R25 terms
Radian
Radio frequency
Ramp
Sawtooth waveform with linear change in V or I.
Sawtooth waveform with linear change in V or I. [1]
Category:
Ratio arm
Accurate, stable resistors in one leg of a Wheatstone bridge or bridge circuit in general.
Accurate, stable resistors in one leg of a Wheatstone bridge or bridge circuit in general. The ratio arm fraction, R1 R2, can be varied in most cases, typically in multiples of 10. The ratio arm fraction in a Wheatstone bridge determines two things; the placement accuracy of the measurement of an unknown resistor, Rx, and the maximum unknown resistance, Rx(max), that can be measured. [1]
Category:
RC phase-shifter
An application of a series RC circuit in which the output across either R or C provides a desired phase shift with respect to the input voltage.
An application of a series RC circuit in which the output across either R or C provides a desired phase shift with respect to the input voltage. RC phase-shifter circuits are commonly used to control the conduction time of semiconductors in power control circuits. [1]
Category:
Reactance
Real number
Any positive or negative number not containing j.
Any positive or negative number not containing j. (A 1 jB) is a complex number but A and B by themselves are real numbers. [1]
Category:
Real power
The net power consumed by resistance.
The net power consumed by resistance. Measured in watts. [1]
Category:
Reciprocal relation
Same as inverse relation.
Same as inverse relation. As one variable increases, the other decreases. [1]
Category:
Reciprocal resistance formula
A formula that states that the equivalent resistance, REQ, of a parallel circuit equals the reciprocal of the sum of the reciprocals of the individual branch resistances.
A formula that states that the equivalent resistance, REQ, of a parallel circuit equals the reciprocal of the sum of the reciprocals of the individual branch resistances. [1]
Category:
Rectangular form
Representation of a complex number in the form A 1 jB.
Representation of a complex number in the form A 1 jB. [1]
Category:
Reflected impedance
Relative permeability
Also called: mr
The ability of a material to concentrate magnetic flux.
The ability of a material to concentrate magnetic flux. Mathematically, relative permeability, designated μr, is a ratio of the flux density (B) in a material such as iron to the flux density, B, in air. There are no units for μr because it is comparison of two flux densities and the units cancel. [1]
Category:
Relative permittivity (r)
A factor that indicates the ability of an insulator to concentrate electric flux, also known as the dielectric constant, K.
A factor that indicates the ability of an insulator to concentrate electric flux, also known as the dielectric constant, K. [1]
Category:
Relay
Resistance
Also called: R
Resistance is opposition to electric current.
Electrical resistance describes how strongly a component or material opposes electric current. The common quantity symbol is R and the SI unit is the ohm (Ω). For a simple resistive circuit, voltage, current, and resistance are related by V = I × R.
Category:
Resistance wire
A conductor having a high resistance value.
A conductor having a high resistance value. [1]
Category:
Resonance
Condition of XL 5 XC in an LC circuit to favor the resonant frequency for a maximum in V, I, or Z.
Condition of XL 5 XC in an LC circuit to favor the resonant frequency for a maximum in V, I, or Z. [1]
Category:
Resonant frequency
The frequency at which the inductive reactance, XL and the capacitive reactance, XC of an LC circuit are equal.
The frequency at which the inductive reactance, XL and the capacitive reactance, XC of an LC circuit are equal. [1]
Category:
Reverse bias
Rheostat
Variable resistor with two terminals to vary I.
Variable resistor with two terminals to vary I. [1]
Category:
Ringing
Root-mean-square (rms) value
For sine-wave AC waveform, 0.707 of peak value.
For sine-wave AC waveform, 0.707 of peak value. Also called effective value. [1]
Category:
S63 terms
Saturation
Saturation region
Sawtooth wave
Scalar
Schmitt trigger
An op-amp comparator that utilizes positive feedback.
An op-amp comparator that utilizes positive feedback. [1]
Category:
Scientific notation
A form of powers of 10 notation in which a number is expressed as a number between 1 and 10 times a power of 10.
A form of powers of 10 notation in which a number is expressed as a number between 1 and 10 times a power of 10. [1]
Category:
Secondary cell or battery
Secondary winding
Self-inductance
Inductance produced in a coil by current in the coil itself.
Inductance produced in a coil by current in the coil itself. [1]
Category:
Semiconductor
Series circuit
Series components
Series opposing
Series string
Series-aiding
Series-aiding voltages
Voltage sources that are connected so that the polarities of the individual sources aid each other in producing current in the same direction in the circuit.
Voltage sources that are connected so that the polarities of the individual sources aid each other in producing current in the same direction in the circuit. [1]
Category:
Series-opposing voltages
Voltage sources that are connected so that the polarities of the individual sources will oppose each other in producing current flow in the circuit.
Voltage sources that are connected so that the polarities of the individual sources will oppose each other in producing current flow in the circuit. [1]
Category:
Shield
Metal enclosure preventing interference from radio waves.
Metal enclosure preventing interference from radio waves. [1]
Category:
Short circuit
Has zero resistance, resulting in excessive current.
Has zero resistance, resulting in excessive current. [1]
Category:
Short time constant
A short time constant can arbitrarily be defined as one that is one-fifth or less the time of the pulse width of the applied voltage.
A short time constant can arbitrarily be defined as one that is one-fifth or less the time of the pulse width of the applied voltage. [1]
Category:
Shunt resistor
A parallel connection.
A parallel connection. A device to increase the range of an ammeter. [1]
Category:
SI
Siemens
Silicon
Semiconductor element used for transistors, diodes, and integrated circuits.
Semiconductor element used for transistors, diodes, and integrated circuits. [1]
Category:
Silicon controlled rectifier
Also called: SCR
A unidirectional semiconductor device, like a diode, that remains in a nonconducting state, although forward-biased, until the forward breakover voltage is reached.
A unidirectional semiconductor device, like a diode, that remains in a nonconducting state, although forward-biased, until the forward breakover voltage is reached. Once conducting, the voltage across the SCR drops to a very low value. [1]
Category:
Sine
Trigonometric function of an angle, equal to the ratio of the opposite side to the hypotenuse in a right triangle.
Trigonometric function of an angle, equal to the ratio of the opposite side to the hypotenuse in a right triangle. [1]
Category:
Sine wave
Skin effect
A term used to describe current flowing on the outer surface of a conductor at very high frequencies.
A term used to describe current flowing on the outer surface of a conductor at very high frequencies. Skin effect causes the effective resistance of a coil to increase at higher frequencies because the effect is the same as reducing the cmil area of the wire. [1]
Category:
Slew rate
Slew-rate distortion
Slip rings
Slow-blow fuse
A type of fuse that can handle a temporary surge current that exceeds the current rating of the fuse.
A type of fuse that can handle a temporary surge current that exceeds the current rating of the fuse. This type of fuse has an element with a coiled construction and is designed to open only on a continued overload such as short- circuit. [1]
Category:
Small signal
Solder
Alloy of tin and lead used for fusing wire connections.
Alloy of tin and lead used for fusing wire connections. [1]
Category:
Solenoid
Source
Spade lug
SPDT
Specific gravity
Ratio of weight of a substance with that of an equal volume of water.
Ratio of weight of a substance with that of an equal volume of water. [1]
Category:
Specific resistance
Speed
Speed is the rate of change of distance with time.
Speed is a scalar: it has magnitude but no direction. It is the rate of change of distance with time. In calculus, speed is the derivative of distance travelled with respect to time. Common units include metres per second (m/s), kilometres per hour (km/h), and miles per hour (mph).
Category:
SPST
Square wave
An almost instantaneous rise and decay of voltage or current in a periodic pattern with time and with a constant peak value.
An almost instantaneous rise and decay of voltage or current in a periodic pattern with time and with a constant peak value. The V or I is on and offfor equal times and at constant values. [1]
Category:
Standard resistor
A variable resistor in one leg of a Wheatstone bridge that is varied to provide equal voltage ratios in both series strings of the bridge.
A variable resistor in one leg of a Wheatstone bridge that is varied to provide equal voltage ratios in both series strings of the bridge. With equal voltage ratios in each series string the bridge is said to be balanced. [1]
Category:
Static electricity
Stator
Steady-state value
Storage cell or battery
Stray capacitance
A very small capacitance that exists between any two conductors separated by an insulator.
A very small capacitance that exists between any two conductors separated by an insulator. The capacitance can be between two wires in a wiring harness or between a single wire and a metal chassis as examples. [1]
Category:
Stray inductance
The small inductance associated with any length of conductor or component lead.
The small inductance associated with any length of conductor or component lead. The effects of both stray inductance and stray capacitance are most noticeable with very high frequencies. [1]
Category:
String
Strings in parallel
Series resistor strings that are connected in parallel with each other.
Series resistor strings that are connected in parallel with each other. [1]
Category:
Summing amplifier
Superconductivity
Superposition theorem
Method of analyzing a network with multiple sources by using one at a time and combining their effects.
Method of analyzing a network with multiple sources by using one at a time and combining their effects. [1]
Category:
Supersonic
Surface-mount resistor
Surface-mount technology
Susceptance
Swamping resistor
An unbypassed resistor in the emitter circuit of a common-emitter amplifier.
An unbypassed resistor in the emitter circuit of a common-emitter amplifier. A swamping resistor stabilizes the voltage gain and reduces distortion. [1]
Category:
Switch
Device used to open or close connections of a voltage source to a load circuit.
Device used to open or close connections of a voltage source to a load circuit. [1]
Category:
Switching contacts
T29 terms
Tail current
Tangent
Also called: tan
Trigonometric function of an angle, equal to the ratio of the opposite side to the adjacent side in a right triangle.
Trigonometric function of an angle, equal to the ratio of the opposite side to the adjacent side in a right triangle. [1]
Category:
Tantalum
Taper
How R of a variable resistor changes with the angle of shaft rotation.
How R of a variable resistor changes with the angle of shaft rotation. [1]
Category:
Tapered control
The manner in which the resistance of a potentiometer varies with shaft rotation.
The manner in which the resistance of a potentiometer varies with shaft rotation. For a linear taper, one-half shaft rotation corresponds to a resistance change of one-half its maximum value. For a nonlinear taper, the resistance change is more gradual at one end, with larger changes at the other end. [1]
Category:
Taut-band meter
Temperature coefficient
For resistance, how R varies with a change in temperature.
For resistance, how R varies with a change in temperature. [1]
Category:
Tesla
Unit of flux density, equal to 108 lines of force per square meter.
Unit of flux density, equal to 108 lines of force per square meter. [1]
Category:
Thermistor
A resistor whose resistance value changes with changes in its operating temperatures.
A resistor whose resistance value changes with changes in its operating temperatures. [1]
Category:
Thevenin’s theorem
Method of reducing a complicated network to one voltage source with series resistance.
Method of reducing a complicated network to one voltage source with series resistance. [1]
Category:
Three-phase power
Threshold voltage
Throw
Thyristor
A semiconductor device with alternating layers of p and n material that can only be operated in the switching mode where they act as either an open or closed switch.
A semiconductor device with alternating layers of p and n material that can only be operated in the switching mode where they act as either an open or closed switch. [1]
Category:
Time constant
Time required to change by 63% after a sudden rise or fall in V and I.
Time required to change by 63% after a sudden rise or fall in V and I. Results from the ability of L and C to store energy. Equals RC or LyR. [1]
Category:
Tolerance
The maximum allowable percent difference between the measured and coded values of resistance.
The maximum allowable percent difference between the measured and coded values of resistance. [1]
Category:
Toroid
Electromagnet with its core in the form of a closed magnetic ring.
Electromagnet with its core in the form of a closed magnetic ring. [1]
Category:
Transconductance
Transformer
Transient response
Temporary value of V or I in capacitive or inductive circuits caused by abrupt change.
Temporary value of V or I in capacitive or inductive circuits caused by abrupt change. [1]
Category:
Transistor
A three-terminal semiconductor device that can amplify an AC signal or be used as an electronic switch.
A three-terminal semiconductor device that can amplify an AC signal or be used as an electronic switch. [1]
Category:
Triac
A bidirectional semiconductor device that remains in a nonconducting state until the forward breakover voltage is reached.
A bidirectional semiconductor device that remains in a nonconducting state until the forward breakover voltage is reached. Once conducting, the voltage across the triac drops to a very low value. Like an SCR, the breakover voltage can be controlled by gate current. [1]
Category:
Trigonometry
Trivalent atom
Troubleshooting
Tuning
Varying the resonant frequency of an LC circuit.
Varying the resonant frequency of an LC circuit. [1]
Category:
Turns ratio
Comparison of turns in primary and secondary of a transformer.
Comparison of turns in primary and secondary of a transformer. [1]
Category:
U4 terms
UHF
Ultra high frequencies in band of 30 to 300 MHz.
Ultra high frequencies in band of 30 to 300 MHz. [1]
Category:
Unijunction transistor
Also called: UJT
A 3-terminal semiconductor device that has only 1 p-n junction.
A 3-terminal semiconductor device that has only 1 p-n junction. UJTs are used to control the conduction angle of an SCR. [1]
Category:
Unipolar
A device having only one type of charge carrier, either electrons or holes.
A device having only one type of charge carrier, either electrons or holes. [1]
Category:
Universal time constant graph
A graph that shows the percent change in voltage or current in an RC or RL circuit with respect to the number of time constants that have elapsed.
A graph that shows the percent change in voltage or current in an RC or RL circuit with respect to the number of time constants that have elapsed. [1]
Category:
V20 terms
Valence electrons
Variac
Transformer with variable turns ratio to provide different amounts of secondary voltage.
Transformer with variable turns ratio to provide different amounts of secondary voltage. [1]
Category:
Vector
A vector is a quantity with both magnitude and direction.
A vector is a quantity with both magnitude and direction. Displacement, velocity, and acceleration are vector quantities.
Category:
Velocity
Velocity is the rate of change of displacement with time and is a vector.
Velocity is the rate of change of displacement with time. It is a vector, so it has both magnitude and direction. The SI unit is metres per second (m/s); common everyday units can also include kilometres per hour (km/h) or miles per hour (mph) when a direction is included. For example, 100 km/h north while driving northbound on Highway 410 describes a velocity, while 100 km/h by itself describes only speed.
Category:
VHF
Very high frequencies in band of 30 to 300 MHz.
Very high frequencies in band of 30 to 300 MHz. [1]
Category:
Volt
Also called: V, volts
The volt (V) is the SI unit of electric potential difference.
The volt, symbol V, is the SI unit used to measure electric potential difference, commonly called voltage. One volt is one joule of energy per coulomb of electric charge.
Category:
Volt-ampere
Also called: VA
Unit of apparent power, equal to V × I.
Unit of apparent power, equal to V × I. [1]
Category:
Volt-ampere characteristic
Volt-ampere reactive
Also called: VAR
The volt-amperes at the angle of 90°.
The volt-amperes at the angle of 90°. [1]
Category:
Voltage
Also called: Potential Difference
Voltage is electric potential difference: energy transferred per unit charge.
Voltage is the electric potential difference between two points. It describes energy transferred per unit charge. The SI unit is the volt (V). In introductory circuit work, voltage is sometimes described as electrical push, but potential difference is the more precise idea.
Category:
Voltage divider
A series circuit to provide V less than the source voltage.
A series circuit to provide V less than the source voltage. [1]
Category:
Voltage drop
Voltage across each component in a series circuit.
Voltage across each component in a series circuit. The proportional part of total applied V. [1]
Category:
Voltage follower
An op-amp circuit with unity voltage gain.
An op-amp circuit with unity voltage gain. A voltage follower has a very high input impedance and a very low output impedance. Voltage followers are also known as unity-gain amplifiers, buffer amplifiers, and isolation amplifiers. [1]
Category:
Voltage gain
Also called: A V
The ratio of output voltage to input voltage in a transistor amplifier or Vin
The ratio of output voltage to input voltage in a transistor amplifier or Vin [1]
Category:
Voltage polarity
The positive and negative ends of a potential difference across a component such as a resistor.
The positive and negative ends of a potential difference across a component such as a resistor. [1]
Category:
Voltage source
Supplies potential difference across two terminals.
Supplies potential difference across two terminals. Has internal series ri. [1]
Category:
Voltage taps
The points in a series voltage divider that provide different voltages with respect to ground.
The points in a series voltage divider that provide different voltages with respect to ground. [1]
Category:
Voltaic cell
Voltmeter loading
VOM
W11 terms
Watt
Watt-hour
Wattmeter
Measures real power as instantaneous value of V × I.
Measures real power as instantaneous value of V × I. [1]
Category:
Wavelength
Wavetrap
An LC circuit tuned to reject the resonant frequency.
An LC circuit tuned to reject the resonant frequency. [1]
Category:
Weber
Also called: Wb
Unit of magnetic flux, equal to 108 lines of force.
Unit of magnetic flux, equal to 108 lines of force. [1]
Category:
Wheatstone bridge
Balanced circuit used for precise measurements of resistance.
Balanced circuit used for precise measurements of resistance. [1]
Category:
Wire gage
A system of wire sizes based on the diameter of the wire.
A system of wire sizes based on the diameter of the wire. Also, the tool used to measure wire size. [1]
Category:
Wire-wound resistors
Resistors made with wire known as resistance wire that is wrapped around an insulating core.
Resistors made with wire known as resistance wire that is wrapped around an insulating core. [1]
Category:
Work
Corresponds to energy.
Corresponds to energy. Equal to power × time, as in kilowatt-hour unit. Basic unit is one joule, equal to one volt-coulomb, or one watt-second. [1]
Category:
Wye network
Three components connected with one end in a common connection and the other ends to three lines.
Three components connected with one end in a common connection and the other ends to three lines. Same as T network. [1]
Category:
X1 terms
XL
Y1 terms
Y network
Z6 terms
Zener current
Also called: IZ
The name given to the reverse current in a zener diode.
The name given to the reverse current in a zener diode. [1]
Category:
Zener diode
A diode that has been optimized for operation in the breakdown region.
A diode that has been optimized for operation in the breakdown region. [1]
Category:
Zero-crossing detector
An op-amp comparator whose output voltage switches to either 6Vsat when the input voltage crosses through zero.
An op-amp comparator whose output voltage switches to either 6Vsat when the input voltage crosses through zero. [1]
Category:
Zero-ohm resistor
A resistor whose value is practically 0 Ω.
A resistor whose value is practically 0 Ω. The 0-Ω value is denoted by a single black band around the center of the resistor body. [1]
Category:
Zero-ohms adjustment
Zero-power resistance
The resistance of a thermistor with zero power dissipation, designated R0.
The resistance of a thermistor with zero power dissipation, designated R0. [1]
Category: