Home

Calculations
Contacts
Conversions
Help
Links
Subjects

Electronics Topics

A: The abbreviation of Ampere, the SI unit of Electric current.
ab: A prefix indicating that an electrical unit is part of the CGS absolute electromagnetic system.
Abampere: The CGS electromagnetic unit of current equal to 10 Amperes.
Abcoulomb: The CGS unit of electric charge equal to 10 Coulomb.
Abfarad: The CGS unit of capacitance equal to 1.0x10⁹Farad.
Abhenry: The CGS unit of inductance equal to 1.0x10^-9Henry.
Abmho: The CGS unit that is the reciprocal of the ohm equal to 1.0x10⁹Siemens.
Abohm: The CGS unit of electrical resistance equal to 1.0x10^-9Ohms.
Absolute Accuracy: A measure of the uncertainty of an instrument reading compared to that of a primary standard traceable to a National standard.
Abvolt: The CGS unit of electromotive force equal to 1.0x10^-9Volt.
AC Brownout: The condition that exists when the ac line voltage drops below some specified value.
AC coupling: Circuit that passes an AC signal while blocking a DC voltage.
AC: An electric current whose direction changes direction with a frequency independent of circuit components.
Acausal: If a system is acausal it means the output begins before the input.
Accelerometer: An instrument for measuring acceleration, as of aircraft or guided missiles.
Accumulator: A device by which energy or power can be stored.
Acorn Valve: An acorn valve is a form of thermionic valve used at ultra-high frequencies.
Acoustic Coupler: An acoustic coupler is means of connecting external devices to a telephone handset avoiding direct electrical connection.
Active Device: A component that has gain or operates in a non-linear fashion to change the basic character of an electric signal by, for example, amplification or rectification.
Active High: The active, true, one, or asserted case of a binary signal is the high or most positive voltage level.
Active Low: The active, true, one, or asserted case of a binary signal is the low or less positive voltage level.
Active Network: A circuit that produces gain.
ADC: Abbreviation of Analogue to Digital converter.
Adcock Aerial: An Adcock aerial is a radio aerial system consisting of two vertical open-spaced dipoles with screened horizontal connections.
Admittance: The ratio of current to voltage, the reciprocal of impedance.
Aerial: Another name for an antenna.
AGC: Abbreviation of Automatic Gain Control.
Alternating Current: An electric current whose direction changes direction with a frequency independent of circuit components.
AM: Where audio signals increase and decrease the amplitude of the "carrier wave".
Ammeter: Instrument for measuring the current in amps, milliamps or microamps.
Ampere: The SI unit of Electric current.
Amplification: Amplifiers are used to provide a number of functions.
Amplifier: A circuit or element that provides gain.
Amplitude Modulation: Where audio signals increase and decrease the amplitude of the "carrier wave".
Analogue: Any representation of a physical quantity in terms of a continuous variation of a second physical quantity.
Analogue to Digital converter: A circuit that converts an analog signal, having a continuously varying amplitude, to a digitally quantized representation using binary output signals.
ANC: This is an electronic method of reducing or removing unwanted sound by the production of a pressure wave of equal amplitude but opposite sign to the nwanted sound.
AND Gate: Gate that produces a logic 1 when all of its inputs are 1. In all other cases the output is 0.
Antenna: A length of wire or similar that radiates (such as a transmitting antenna) or absorbs (such as a radio antenna) radio waves.
Antistatic: Of or pertaining to the ability to either prevent the accumulation of or to enable the dissipation of static charge.
Aperture Delay: In an analog-to-digital converter, the delay in time from when the user requests the analog input to be sampled and the actual time when this occurs.
Aperture Jitter: The amount of variance in the aperture delay.
Application Specific Integrated Circuit: An integrated circuit designed for a custom requirement, frequently implemented in a gate array or field programmable array.
ASIC: An abbreviation of Application Specific Integrated Circuit.
Asserted High: The asserted, true, one, or active case of a binary signal is the high or most positive voltage level.
Asserted Low: The asserted, true, one, or active case of a binary signal is the low or less positive voltage level.
Astable: A circuit that has no stable state and thus oscillates at a frequency dependent on component values.
Attenuator: A two port circuit or device that reduces the amplitude of an input signal by a desired amount typically expressed in decibels.
Audio Amplifier: An amplifier designed specifically for amplifying audio signals in the frequency range 20Hz to 20kHz.
Automatic Gain Control: A circuit that adjusts the gain of a stage so that the volume is constant even though the input signal may vary over a wide range.
Avalanche: A cumulative ionization process.
B: An abbreviation of bel, the logarithm of the ratio of two powers. The decibel is one tenth of a bel.
Balun: A transformer circuit that couples a balanced transmission line to an unbalanced transmission line.
Band Gap Energy: For semiconductors and insulators, the energies that lie between the valence and conduction bands.
Base Terminal: That electrode of a transistor which compares generally to the grid of a vacuum tube.
Battery: A group of voltaic cells connected in series.
bel: The bel is the logarithm of the ratio of two powers, and the decibel is one tenth of a bel.
Beta: The current gain in a grounded-emitter transistor amplifier.
Bias: Used in recording signals on a magnetic media (tape). As the tape passes the recording head, the head generates a varying magnetic field corresponding to the analogue signal to be recorded.
Bifilar Winding: Two conductors wound in parallel.
Biot-Savart Law: A law describing the magnetic flux density at a distance r away from an electrical conductor.
Bipolar: A signal that swings both above and below analog ground, thus having positive and negative values.
Bistable: Circuit that has two stable states.
Bit: Binary Digit - the smallest unit of binary data.
Bitrate: The rate at which the compressed bitstream is delivered from the storage medium to the input of a decoder.
Bitstream: An ordered series of bits that forms the coded representation of the data.
Bleeder Current: A current drawn continously from a souce.
Bleeder Resistor: A resistor that allows a small current drain on a power source to discharge filter capacitors or to stabilize an output.
BNC Connector: A twist lock bayonet coaxial connector commonly used in applications involving small coaxial cables.
Bottoming: A transistor in the fully conducting state.
Breadboard: An assembly of preliminary circuits.
Breakdown Voltage: Voltage at which the breakdown of a dialectric or insulator occurs.
Bridge Rectifier: A full-wave rectifier in which there are four arms - each containing a diode.
Broad Band Signal: A random signal containing a wide range of frequency components. Some types of electrical noise in a cable and acoustic noise from turbulent flow tend to be broad band.
Brush DC Motors: The Brush DC motors use commutators and carbon brushes to apply current through the windings as the motor rotates.
Brushless DC Motors: The BLDC motor uses electronic commutation to control the current through the windings.
Burn In: The operation of a newly fabricated device or system prior to application with the intent to stabilize the device, detect defects, and expose infant mortality.
Bus: Transmission medium for electrical or optical signals that perform a particular function, such as computer control.
Busbar: Copper bar or section used for carrying heavy currents, generally rigid when compared to cables.
By-Pass Capacitor: A capacitor that provides a path of low impedance - low resistance to AC signals.
Capacitance: The capacitance is defined as the total electric charge on a body divided by its potential.
Capacitor: An electrical component that passes alternating currents but blocks direct currents.
Capacitor Microphone: Microphone whose operation depends on variations in capacitance caused by varying air pressure on the movable plate of a capacitor.
Carbon Microphone: Microphone whose operation depends on pressure variation in carbon granules causing a change in resistance.
Carrier Suppression: The degree to which the carrier signal is reduced in amplitude in a modulator or mixer.
Cathode Ray Tube: An evacuated tube containing an anode and a cathode that generates cathode rays when operated at a high voltage.
CCD: Abbreviation of Charge Coupled Device.
Central Processing Unit: The computer chip primarily responsible for executing instructions.
Centre Frequency: Frequency to which an amplifier is tuned. The frequency half way between the cut-off frequencies of a tuned circuit.
Centre Tap: Midway connection between the two ends of a winding.
Ceramic Capacitor: Generally a single layer capacitor that is flat and has a brown coating, Also have the name monoblock or monolithic in which the capacitor is made even smaller by creating multy-layers and coated in orange or blue paint.
Channel: A frequency interval or frequency band assigned for communications.
Characteristic Impedance: The ratio of voltage and current at every point along a transmission line on which there are no standing waves.
Charge Coupled Device: A self-scanning semiconductor imaging device which uses metal-oxide-semiconductor, surface storage and information transfer technologies.
Chip: A piece of semiconductor substrate on which active and/or passive circuit elements have been fabricated.
Choke: An inductor designed to present a high impedance to alternating current.
Circuit: Interconnection of components to provide an electrical path between two or more components.
Circuit Breaker: A protective device used to open a circuit when current exceeds a maximum value.
Clipper Circuit: A circuit that blocks or removes the portion of a voltage waveform above some threshold voltage.
Closed Loop: A system in which the output is used to control the input.
CMOS: Family of logic devices that uses p-type and n-type channel devices on the same IC.
Coaxial Cable: A round cable with a central conductor and screening around with a insulating medium between.
Collector: One terminal of a transistor.
Common Base Connection: Same as ground base connection. A mode of operation of a transistor in which the base is common to both the input and output circuits and is usually earthed.
Common Collector Connection: A mode of operation of a transistor in which the collector is common to both the input and the output circuits and is usually connected to one of the power rails.
Common Emitter Connection: A mode of operation for a transistor in which the emitter is common to the input and output circuits. The base is the input terminal and the collector is the output terminal.
Common Return: return conductor common to two or more circuits.
Common-Mode Rejection Ratio: The ability of the differential amplifier to obtain the difference between the + and - inputs whilst rejecting the signal common to both.
Common-Mode Signal: A signal applied simultaneously to both inputs of a differential amplifier.
Complementary Transistor: A PNP and NPN pair used in a push-pull circuit.
Compliance Voltage: The output dc voltage of a constant current supply.
Complimentary Metal Oxide Semiconductor: Family of logic devices that uses p-type and n-type channel devices on the same IC. It has the advantage of offering medium speed and very low power requirements.
Condenser: An old fashioned name for a capacitor.
Conduction Band: Lowest empty or partially filled band in a semiconductor.
Conductor: A material that allows the passage of electric charge or the easy transfer of thermal energy.
Control Loop: Feedback circuit used to control an output signal.
Control Variable: The inputs and outputs which a control system manipulates and measures to keep proper control.
Corner Frequency: The frequency at which linear extrapolations of two contiguous sections of a device's or component′s transfer function drop by 3 decibels.
CPU: Abbreviation of Central Processing Unit, the computer chip primarily responsible for executing instructions.
Cross Talk: Unwanted breakthrough of one channel into another.
Crossover Frequency: In a loudspeaker with multiple radiators, the crossover frequency is the 3dB point of the network dividing the signal energy.
Crowbar: Circuit used to protect the output of a source from a short circuited load.
CRT: An evacuated tube containing an anode and a cathode that generates cathode rays when operated at a high voltage.
Crystal Controlled Oscillator: Oscillator that uses a quartz crystal in its feedback path to maintain a stable output frequency.
Current: Current is often used to transmit signals in noisy environments because it is much less affected by environmental noise pick-up.
Current Density: Amperes per unit area.
Current Sink: This refers to a sensor output configuration which switches a voltage to the negative side of the power supply.
Current Source: This refers to a sensor output configuration which provides a source of current to the load.
Cutoff: A transistor operating mode where very little current flows between the collector and emitter.
Darlington Pair: Two directly coupled transistors in which the emitter of the first drives the base of the second.
DC: A current that does not change in direction.
DC DC Converter: A circuit or device that changes a dc input signal value to a different dc output signal value.
Delay Line: A transmission line or circuit that imposes a desired amount of propagation delay on an incident signal.
Demodulation: The process of recovering intelligence from a signal, some parameter of which was modified to carry the intelligence.
Dielectric Losses: Power losses due to the conductance of dielectric materials.
Differential Amplifier: One whose output is proportional to the difference between two inputs.
Differential Input: Often used to reduce noise picked up by the signal leads.
Differential Voltage: The difference in voltages at two points as measured with respect to a common reference.
Digital Circuit: A collection of logic gates used to process or generate digital signals.
Digital Signal Processing: The term used for calculations performed on digital signals.
Diode: A semiconductor that allows current to flow in one direction only.
Diode Drop: The forward voltage developed across a diode when it is operating.
Diode Transistor Logic: Logic gates implemented using particular configurations of diodes and bipolar junction transistors.
Diplexer: A circuit or system that allows the ability to transmit and receive two distinct signals simultaneously.
Direct Coupled Amplifier: An amplifier in which the output of one stage is coupled to the input of the next without the use of a capacitor.
Direct Current: A current that does not change in direction.
Direct Current Amplifier: A direct coupled amplifier that can provide gain for zero-frequency signals.
Distributed Capacitance: Capacitance that is not concentrated within a lumped capacitor, but spread over a circuit or group of components.
Distributed Inductance: Inductance that is not concentrated within a lumped inductor, but spread over a circuit or group of components.
Dither: The noise added to a signal prior to quantization which reduces the distortion and noise modulation resulting from the quantization process.
DPDT Switch: Abbreviation of Double-Pole, Double-Throw switch.
DPST Switch: Abbreviation of Double-Pole, Single-Throw switch.
Drift: Motion of carriers caused by an electric field.
DSP: Abbreviation of Digital Signal Processing, the term used for calculations performed on digital signals.
D-Sub Connector: A connector whose male end has a D shaped raised shield that protects the connecting pins.
DTL: Logic gates implemented using particular configurations of diodes and bipolar junction transistors.
Duty Cycle: The ratio of operating to non-operating time for a device.
Dynamic Range: The power range over which a component or system functions properly.
earth: Can mean a connection to the earth itself or the negative lead to the chassis or any point to zero voltage.
Eddy Currents: Circulating currents within inductor core material caused by magnetic lines of force cutting across the core in a direction which induces a voltage in the core material.
Electric Motor Noise: There are numerous applications of electric motors and the type of noise produced by each may be very specific to the installation and type of motor.
Electric Motors: There are a number of different types of electric motor: AC Induction Motors, Brush Direct Current Motors, Brushless Direct Current Motors and Stepper Motors.
Electrical Impedance: Impedance of a linear circuit element with two terminals is the ratio of the complex sinusoidally varying voltage applied across the terminals to the complex current that flows in response.
Electrical Length: Physical length expressed in terms of the wavelength of a signal for the medium in which the component or structure is situated.
Electrical Screen: A metal shield which isolates a device from external fields.
Electrolytic Capacitor: A type of capacitor that has a liquid or paste between the plates to increase its capacitance.
Electromagnetic Compatibility: The capability of different electrical systems to coexist in the electromagnetic environment without causing or being subjected to interference.
Electromagnetic Field: Electric and magnetic forces that exist in a physical volume.
Electromagnetic Radiation: The emanation of an electromagnetic field from a source through space.
Electrostatic Sensitivity: The degree to which a component or device is susceptible to damage by electrostatic discharge.
Emitter: One terminal of a transistor. Compares generally to the cathode of a tube.
Emitter Coupled Logic: Where transistors are held in the turned-on state to increase the speed of the gate.
Emitter Follower: A transistor circuit comparable to the cathode-follower tube circuit. (Also called grounded collector.)
Exclusive Or Gate: Logic element that features two inputs. The output will be 1 only when one or the other (but not both) is logic 1. In all other cases the output is 0.
Far Field: The distribution of sound energy at a very much greater distance from a sources than the linear dimensions of the source and in which the sound waves can be considered to be plane waves.
Feedback: Occurs when some or all of the output of the device (such as an amplifier) is taken back to the input.
Ferrite: A solid solution of one or more elements in body-centered cubic iron.
Ferrite Rod Aerial: A coil of wire wound on a ferrite material to increase the inductance of the coil. It's signal capturing capability.
Fibre Washer: Used in many different applications for electrical or thermal insulation, to distribute the load or to add some complaince to the bolted structure.
Field Effect Transistor: A transistor that makes use of the field established in a p-type channel semiconductor material to control the flow of current through the channel.
Filter: Any of various electric, electronic, acoustic, or optical devices used to reject signals, vibrations, or radiation of certain frequencies while passing others.
Finite Impulse Response Filter: A commonly used type of digital filter. Digitized samples of the audio signal serve as inputs, and each filtered output is computed from a weighted sum of a finite number of previous inputs.
Fir: A light coloured and soft wood. Needs to be dried very well before use.
FIR Filter: A commonly used type of digital filter. Digitized samples of the audio signal serve as inputs, and each filtered output is computed from a weighted sum of a finite number of previous inputs.
Flip Flop: An astable multivibrator.
Flywheel Effect: The continuous interchange of electric energy between the capacitor and inductor of a parallel resonant circuit wherein the energy level is diminished only by circuit resistance and radiated energy.
FM: An abbreviation of Frequency Modulation where the information signal is used to vary the carrier signal frequency.
Footprint: The area occupied by a device or machine.
Forward Bias: The bias applied between the base and emitter of a transistor to coincide with the P and N zone polarities.
Frequency Counter: Counts digital pulses over a defined gate time.
Frequency Modulation: The information signal is used to vary the carrier signal frequency.
Fuel Cell: A device that converts the chemical energy obtained from a redox reaction directly into electrical energy.
Full Duplex: Operational mode of a communication circuit in which each end can simultaneously transmit and receive data.
Fuse: A short length of wire that will easily burn out when excessive current flows.
Gain: The ratio of the output level of a circuit to the input. This will be positive for an amplifier and negative for an attenuator.
Galvanometer: An instrument for detecting and measuring a small electric current by movements of a magnetic needle or of a coil in a magnetic field.
Gate: One of the terminals of a Field Effect Transistor (FET).
Greencap Capacitor: A type of polyester capacitor that the manufacturer dips in green paint to make it distinctive from all other capacitors.
Ground Plane: The earth or negative rail of a circuit. A large or significant mass that presents the effect of earth (ground) to a signal.
Grounded Base: A transistor amplifier circuit comparable to the grounded-grid (signal ground) tube circuit.
Grounded Collector: A transistor circuit comparable to the cathode-follower tube circuit. (Also called emitter follower.)
Grounding: Establishing an electric connection to the Earth in order to neutralize an object.
Half Duplex: Describes a circuit capable of transmitting in either direction, but only one direction at a time.
Half Wave Rectifier: A tube or solid-state diode which passes current in only one direction and thus converts ac to pulsating dc by rectification of one alternation of each cycle.
Hall Effect: The phenomenon whereby a force is brought to bear on a moving electron or hole by a magnetic field that is applied perpendicular to the direction of motion.
Hall Mobility: A measure of the flow of charged particles perpendicular to both a magnetic and an electric field.
Handshaking: The initial exchange between two communications systems prior to and during transmission to ensure proper data transfer.
Headroom: A term related to dynamic range, used to express in dB, the level between the typical operating level and the maximum operating level above which the signal will be clipped.
Heat Pipe: A device that can transfer large amounts of heat with a small difference in temperature between the hot and cold interface.
Heat Sink: A structure that is mechanically attached to a device that generates heat.
Heaviside Oliver: An English electrical engineer who introduced Laplace transforms into electrical engineering.
Heptode: A high-vacuum thermionic valve having seven electrodes.
Hertz: The SI unit of frequency indicating the number of cycles per second (symbol Hz).
Hertz Heinrich: A German physics professor who did the first experiments with generating and receiving electromagnetic waves, in particular radio waves.
Hertzian Waves: Now generally called radio waves.
High Tension: A comparative term used in electronics to denote high voltages.
IC: An abbreviation of Integrated Circuit, first proposed by G. W. A. Dunner in 1952.
IEE: The IEE is an innovative international organisation for electronics, electrical, manufacturing and IT professionals.
IIR: Abbreviation of Infinite Impulse Response filter, a commonly used type of digital filter.
Impedance: Mechanical impedance is the ratio of a force-like quantity to a velocity like quantity when the arguments of the real (or imaginary) parts of the quantities increase linearly with time.
Impulse: The product of the force and the time during which it acts.
In Phase: Two periodic waves reaching peaks and going through zero at the same instant are said to be "in phase."
Induced Current: Current that flows as a result of an Induced EMF.
Inductance: The property of an electric circuit to store magnetic energy when carrying a current.
Inductor: A magnetic device that stores energy in a magnetic field produced by flowing current.
Infinite Impulse Response Filter: A commonly used type of digital filter. This recursive structure accepts as inputs digitized samples of the audio signal, and then each output point is computed on the basis of a weighted sum of past output (feedback) terms, as well as past input values.
Insertion Loss: This may be applied to a silencer or other sound-reducing element, in a specified frequency band, the decrease in sound power level, measured at the location of the receiver, when a sound insulator or a sound attenuator is inserted in the transmission path between the source and the receiver.
Institution of Electrical Engineers: The IEE is an innovative international organisation for electronics, electrical, manufacturing and IT professionals, with specifically tailored products, services and qualifications to meet the needs of today′s technology industry.
Integrated Circuit: First proposed by G. W. A. Dunner in 1952.
Interference: The combining of two or more signals results in an interaction called interference.
Intrinsic Carrier Density: The density of electrons and holes in an intrinsic semiconductor.
Intrinsic Semiconductor: A semiconductor free of defects or impurities.
Inverter: A circuit in both analogue and digital systems that provides an output that is inverse to the input. Also a circuit that converts DC to AC.
JFET: A three-terminal transistor device where the output current flowing between the source and drain terminals is controlled by a variable electric field applied to the gate terminal. The gate design determines the type of FET: either JFET (junction FET) or MOSFET (metal-oxide semiconductor FET).
J-Type Thermocouple: Iron-constantan thermocouple with a temperature range of 0 to 750°C.
kilowatt: One thousand watts.
K-Type Thermocouple: Chromel-Alumel thermocouple with a temperature range of -200 to 1200°C.
LCD: Abbreviation of Liquid Crystal Display.
LDR: A layer of Cadmium Sulphide material that changes resistance according to the amount of light falling on it.
Lead Acid Battery: A battery with electrodes of lead oxide and metallic lead that are separated by an electrolyte of sulphuric acid.
LED: A diode that emits light when current is passed through it.
Lenzs Law: A basic law which states that an induced current set up by the relative motion of a conductor and a magnetic field always flows in such a direction as to form a magnetic field which opposes the motion.
Light Dependent Resistor: A layer of Cadmium Sulphide material that changes resistance according to the amount of light falling on it.
Light Emitting Diode: A diode that emits light when current is passed through it.
Linear Variable Differential Transformer: An inductance element that produces an electrical output proportional to the displacement of a separate movable core; used to measure position.
Liquid Crystal Display: A thin and flat display device made up of a number of colour or monochrome pixels arrayed in front of a light source or reflector.
Lissajou′s Figures: The pattern traced out when the displacements of two simple harmonic motions are traced in the x and y direction.
Lithium Ion Battery: Lithium ions are added to a carbon electrode instead of using metallic lithium as the anode.
Lithium Polymer Battery: The battery has a lithium anode that is separated from the cathode by a thin polymer electrolyte.
Load: The weight supported by a structure.
Loudspeaker: An electroacoustical transducer that changes electrical energy to acoustical energy.
LSB: Abbreviation of Least Significant Bit, the bit within a digital word that represents the smallest possible coded value.
LVDT: An inductance element that produces an electrical output proportional to the displacement of a separate movable core; used to measure position.
Machine: Any mechanical or electrical device that performs a task for people.
Mains Noise: Unwanted noise in electrical signals related to mains signals.
Majority Carriers: The term used in transistor design to indicate the primary current-movement process.
Mayer Method: A method of evaluating the propagation delay of a transmission line.
Mean Time Between Failure: The average time between failures for a continuously operating system.
Mean Time to Failure: The measured operating time of a system or component divided by the number of failures that occurred during that time.
Megohm: One million ohms.
Memory: In a computer system memory is used to store data temporarily or permanently. The capacity of the memory is normally measured in bytes.
MEMS: Abbreviation of Micro Electro Mechanical Systems.
Metal-Oxide-Silicon-Field-Effect-Transistor: In a MOSFET device the gate is insulated from the channel by a very thin (typically less than the wavelength of light) layer of glass (silicon dioxide) and the gate is either metal or doped silicon (polysilicon), hence the acronym metal-oxide semiconductor.
Mho: The unit of conductance, transconductance, or admittance; it is the word ohm spelled backwards.
Micro Electro Mechanical Systems: A technology dealing with building mechanical structures on silicon wafers using integrated circuit processing techniques.
millivolt: A unit of electrical potential equal to one thousandth of a volt.
Minority Carriers: The conduction band holes in n-type material and valence band electrons in p-type material.
Mismatch Loss: The loss of power delivered into a load as a result of the interconnection of devices having unequal impedances.
Modem: A device whose name combines the term modulate with demodulate which refers to its ability to transmit and receive data superimposed on a carrier frequency.
Monostable: Circuit with two states. Only one state is stable.
Moore′s Law: This states that the number of devices on a silicon chip could double each year.
MOSFET: In a MOSFET device the gate is insulated from the channel by a very thin (typically less than the wavelength of light) layer of glass (silicon dioxide) and the gate is either metal or doped silicon (polysilicon), hence the acronym metal-oxide semiconductor.
Most Significant Bit (MSB): The bit within a digital word that represents the biggest possible single-bit coded value.
MSB: Abbreviation of Most Significant Bit, the bit within a digital word that represents the biggest possible single-bit coded value.
MTBF: The average time between failures for a continuously operating system.
MTTF: The measured operating time of a system or component divided by the number of failures that occurred during that time.
Multimeter: Electronic meter that displays voltage, current and resistance.
Multivibrator: A building block in which the output is either High or Low. There are three foms of multivibrator: Monostable, bi-stable and astable. The monostable has only one stable state, the bi-stable has two stable states and the astable is free-running (no stable states).
mV: An abbreviation of millivolt, a unit of electrical potential equal to one thousandth of a volt.
Nand Gate: Gate whose output is 0 when both input are 1 and 1 in all other cases.
Negative Feedback: Feedback from the output of an analogue circuit that tends to oppose the input.
Negative Ground: A system where the negative terminal of the source is connected to the system′s metal chassis.
Negative Resistance: A device having negative voltage-current characteristics.
Negative Temperature Coefficient: A term used to describe a component whose resistance or capacitance decreases when temperature increases.
Neon Bulb: Glass envelope filled with neon gas which when ionized by an applied voltage will glow red.
Nicad: Abbreviation of Nickel Cadmium Battery.
Nickel Cadmium Battery: The battery has a nickel-hydroxide cathode, a cadmium anode, and aqueous potassium hydroxide electrolyte.
Nickel Metal Hydride Battery: The battery has a nickel-hydroxide cathode, a metal hydride anode, and aqueous potassium hydroxide electrolyte.
NiMH: A common abbreviation for Nickel Metal Hydride Battery.
N-JFET: A three-terminal transistor device where the output current flowing between the source and drain terminals is controlled by a variable electric field applied to the gate terminal. The gate design determines the type of FET: either JFET (junction FET) or MOSFET (metal-oxide semiconductor FET).
N-MOSFET: In a MOSFET device the gate is insulated from the channel by a very thin (typically less than the wavelength of light) layer of glass (silicon dioxide) and the gate is either metal or doped silicon (polysilicon), hence the acronym metal-oxide semiconductor.
Noise: Noise is any undesired signal.
Noise Floor: Normally the lowest threshold of useful signal level.
Nor Gate: Gate whose output is 0 if any of its inputs is a 1.
Not Gate: Logic element that acts as an inverter.
Notch Filter: An electronic network which passes signals having frequencies above and below the band-elimination frequency span.
NPN Transistor: Type of bipolar transistor using n-type p-type n-type material in its manufacture.
N-Type Thermocouple: Nicrosil-Nisil thermocouple with a temperature range of -200 to 1200°C.
Nyquist Frequency: Half the sampling frequency. Any analog frequency component above the Nyquist frequency will, after sampling, be converted (aliased) to a frequency below the Nyquist frequency.
Offset Error: If you get a reading other than zero for a zero condition then you have an offset error.
Ohmmeter: Device used to measure electrical resistance.
Open Circuit Voltage: The voltage between the terminals of a battery or power source when no current is flowing.
Open Loop: A system operating without feedback.
Open Loop Gain: Gain of an amplifier when no feedback is present.
Operating Point: That point in the characteristics of a tube or transistor around which the signal voltages vary.
Operational Amplifier: One of the basic building blocks of analogue circuits.
Or Gate: Logic gate whose output will be a 1 if any of it imputs is at 1.
Oscillator: A regenerative circuit which has signal-generating characteristics.
Oscilloscope: An instrument using a cathode-ray tube for visual display of electric signals.
PCM: Coding where the input signal is represented by a given number of fixed-width samples per second.
Peak to Peak Value: The over-all amplitude of a signal measured from its lowest peak to its most highest peak.
Peak Value: The instantaneous maximum value of a waveform.
pF: Abbreviation of picofarad, the farad is the SI unit of capacitance.
Phase: Phase identifies the position at any instant which a periodic wave occupies in its cycle. A portion of a material system whose properties and composition are homogeneous and which is physically distinct from other parts of the system.
Photoelectric Effect: The ejection of electrons from metallic surfaces by illuminating light.
Phototransistor: A transistor with a window on the top face to allow light to fall on the active surface.
Photovoltaic Cell: A unit which generates a voltage related to the light intensity impinging on it.
Piezoelectric: Any material which provides a conversion between mechanical and electrical energy.
Pixel: Single picture element of a detection device.
P-JFET: A three-terminal transistor device where the output current flowing between the source and drain terminals is controlled by a variable electric field applied to the gate terminal. The gate design determines the type of FET: either JFET (junction FET) or MOSFET (metal-oxide semiconductor FET).
P-MOSFET: In a MOSFET device the gate is insulated from the channel by a very thin (typically less than the wavelength of light) layer of glass (silicon dioxide) and the gate is either metal or doped silicon (polysilicon), hence the acronym metal-oxide semiconductor.
PNP Transistor: Type of bipolar transistor using p-type, n-type, n-type semiconductor material.
Potentiometer: A variable resistor with three terminals-one on each end of the resistor and one "wiper" which contacts the resistor midpoint to indicate a variable position.
Potting Compound: An insulating material for encapsulating one or more circuit elements.
Primary Cell: A cell or battery which is not intended to be recharged and is discarded when the cell or battery has delivered all its electrical energy.
Protocol: The set of conventions that govern the treatment and formatting of data in an electronic communications system.
Pulse Code Modulation: Coding where the input signal is represented by a given number of fixed-width samples per second.
PV Cell: Abbreviation of Photovoltaic Cell.
Q: The quality factor defines the sharpness of resonance.
Quality Factor: The quality factor defines the sharpness of resonance.
Quantization Error: When a continuous time signal is digitized, because there isn′t an infinite number of discrete digital levels, the difference between the actual analog value and the digital representation of that value is defined as the quantization error.
Quiescent Current: The standing current that flows in a circuit when the signal is not applied. The quiescent current is usually very low or lower than when processing a signal.
Radio Frequency Choke: A choke coil with a high impedance at radio frequencies.
Radio Frequency Interference: This is unwanted Electromagnetic Emissions in the radio reception bands.
Radio Waves: Electromagnetic radiation in the region of the spectrum smaller than about 3 x 10⁸Hz and wavelengths greater than about 1 m.
RAM: Abbreviation of Random Access Memory, a data storage device for which the order of access to different locations does not affect the speed of access, except for bursts.
Random Access Memory: A data storage device for which the order of access to different locations does not affect the speed of access, except for bursts.
Range: The maximum and minimum allowable full-scale signal.
Reactance: The opposition to the flow of electricity posed by capacitors and inductors.
Recursive Filter: A filter in which there is no need to store past measurements for the purpose of calculating current estimates.
Resistance: The electrical resistance of a conductor.
Resistor: Passive component with a known resistance. The value of resistance is usually shown by a set of coloured bands on the body of the component.
RF Choke: A choke coil with a high impedance at radio frequencies.
Rheostat: A device to regulate the flow of electric current by transforming part or all of it into heat.
Ribbon Cable: Any cable constructed as a ribbon with parallel elements.
Rise Time: The time required for the output of a transducer to rise from 10% to 90% of its final value, as it responds to a step change in the measurand.
RS232: Serial communications system.
SDRAM: Abbreviation for Synchronous Dynamic Random Access Memory, SDRAM delivers bursts of data at high speeds using a synchronous interface.
Secondary Cell: A galvanic battery which, after discharge, may