Electronic Components Glossary

New to electronics and circuitry? Here's a handy glossary of often used words and phrases.

555 Timer: Introduced by Signetics in 1971, the 555 timer is still one of the most popular ICs. It is used in timer and multivibrator applications.

Alligator Clips: Used to temporarily hold an electrical connection together for testing or soldering. Often made of nickel plated steel. Can be found with vinyl insulators.

Alternating Current: An electric current that reverses direction in a circuit at regular intervals.

Amplitude: The maximum absolute value reached by a voltage or current waveform.

Anode: The anode of a device is the terminal where current flows in.

AWG: American Wire Gauge - a system of measuring wire size

Bandwidth: The width of the range or band of frequencies that an electronic signal uses on a given transmission medium. Here bandwidth is expressed in terms of the difference between the highest frequency signal component and the lowest frequency signal component.

Biasing: The method of establishing predetermined voltages and/or currents at various points of a circuit to set the appropriate operating point.

Bipolar: Relating to a device capable of using two polarizations, such as a transistor that uses positive and negative charge carriers.

Breadboard: A thin plastic board full of holes used to hold components that are wired together. It is commonly used for prototyping and experimenting with circuit designs.

Bridge Rectifier: A rectifier with four elements connected as a bridge circuit with direct voltage secured from one pair of opposite junctions when alternating voltage is applied to the other pair.

Cable: A bound or sheathed group of mutually insulated conductors.

Capacitance: The property of a capacitor to hold a charge. It is measured in Farads

Capacitor: A device used in electrical circuits . The capacitor stores an electrical charge for a short period of time, and then returns it to the circuit. Common types of capacitors include tantalum, electrolytic, ceramic, and film capacitors.

Cathode: The cathode of a device is the terminal where current flows out.

Ceramic Capacitor: A ceramic capacitor is a capacitor constructed of alternating layers of metal and ceramic , with the ceramic material acting as the dielectric.

Circuit: A configuration of electrically or electro magnetically connected components or devices.

Closed Circuit: An electric circuit providing an uninterrupted, endless path for the flow of current.

Closed Position: Relating to switches - the position in which current can flow.

CMOS: Abbreviation for complementary metal oxide semiconductor, a class of integrated circuits.

Cold Solder Joint: A faulty joint in electric wiring which results from the application of insufficient heat at the joint. The solder merely covers the joint and is not physically attached.

Commutator: A device used in an electric generator to convert the alternating current produced in the generator into direct current before the current is sent into an external circuit. It is basically a rotary switching device synchronized with the frequency of the alternating current. Commutators are also used in electric motors to switch currents in order to maintain magnetic polarities necessary to keep the shafts of the motors turning.<

Conductor: Conductors, such as an electrical connector, are materials that readily conduct electric current through electrical conduction.

Connector: A device that joins to other conductors and to the terminals of apparatus and equipment.

Continuity: Occurs when a complete path for current exists.

Current: The amount of electric charge flowing past a specified circuit point per unit time.

Decoder: A circuit that responds to a particular coded signal while rejecting others.

Desolder Pump: Equipment that removes excess solder via a vacuum.

Diode: A device that restricts current flow chiefly to one direction

Direct Current: (DC) Electric current flowing in one direction only.

Double Pole Double Throw Switch (DPDT): A six terminal switch or relay contact arrangement that simultaneously connects one pair of terminals to either of two other pairs of terminals (two input and four output).

Double Pole Single Throw Switch (DPST): A four terminal switch or relay contact arrangement that simultaneously opens or closes two separate circuits or both sides of the same circuit (two input and two output).

Dual In Line Package (DIP): Integrated circuit package that has two rows of connecting pins.

Electricity: A flow of electrical charges such as electrons through a conductor.

Electrolytic Capacitors: An electrolytic capacitor is a type of capacitor typically with a larger capacitance per unit volume than other types, making them valuable in relatively high-current and low-frequency electrical circuits.

Electromagnet: A magnet consisting basically of a coil of insulated wire wrapped around a soft iron core that is magnetized only when current flows through the wire.

Electromotive Force: Measured in volts, a force that exists between postive and negative charges.

Electron: An elementary particle which is the negatively charged constituent of ordinary matter.

Encoder: An encoder is a device used to change a signal or data into a code.

ESD: Electrostatic discharge is the form of current that is left within an insulating body after the power source is removed.

Farad: The unit of electric capacity; capacity to hold 1 coulomb with a potential of 1 volt.

Ferrite Core: A device placed on cables and wires to reduce RF interference.

Fuse: A device that protects an electric circuit from excessive current.

Gain: An increase in signal power, voltage, or current by an amplifier, expressed as the ratio of output to input. Also called amplification.

Gauge: A system to measure wire or tubing diameter.

Ground: A conducting object, such as a wire, that is connected to such a position of zero potential.

Heatsink: A mass of metal that is added to a device for the purpose of drawing off and dissipating heat; used with power transistors and many types of metallic rectifiers. Also known as dissipator.

Hertz (Hz): A unit of frequency, equal to one cycle per second; symbol. Abbreviated as Hz.

High Pass Filter: A filter that blocks low frequencies and allows high frequencies to pass through.

I: Symbol that represents 'Current'.

IC: Abbreviation for Integrated Circuit which is a microscopic array of electronic circuits and components that has been diffused or implanted onto the surface of a single chip of semiconducting material such as silicon.

Impedence: Opposition that a circuit presents to electric current. It includes both resistance and reactance.

Inductance: The property of an electric circuit or of two neighboring circuits whereby an electromotive force is induced by the process of electromagnetic induction in one of the circuits by a change of current in either of them.

Inductors: A device for introducing inductance into a circuit.

Infrared (LEDs): Infrared is an invisible band of radiation at the lower end of the visible light spectrum. With wavelengths from 750 nm to 1 mm, infrared starts at the end of the microwave spectrum and ends at the beginning of visible light. Infrared transmission typically requires an unobstructed line of sight between transmitter and receiver.

Insulator: A material that does not easily transmit energy, such as electric current.

Integrated Circuit (IC): An IC is a microscopic array of electronic circuits and components that has been diffused or implanted onto the surface of a single chip of semiconducting material such as silicon.

Inverter: A device used to convert direct current into alternating current. Also, a type of logic gate with a single input.

Jack: A type of connector.

K Ohm: One thousand ohms.

Live Circuit: A circuit with applied voltage.

Logic Gate: A electronic device that performs a logical operation on an input signal.

Low Pass Filter: A filter designed to transmit electromagnetic frequencies below a certain value, while excluding those of a higher frequency.

Lug: A fitting to which wires can be attached.

Lumens: A lumen is a unit of luminous flux. It is represented by the abbreviation 'lm'. One lumen equals the amount of light emitted in a solid angle from a source that radiates to an equal extent in all directions.

Microcontroller: Known as an MCU, a microcontroller is a type of microprocessor that can contain an entire "computer on a chip".

MOV (Metal Oxide Varistor): A two electrode device having a voltage dependent nonlinear resistance; its resistance drops as the applied voltage is increased. Also known as voltage dependent resistor. Abbreviated as MOV.

Multimeter: An instrument that measures electrical quantities such as voltage, resistance and amperage.

N Type Semiconductor: A semiconductor to which doping material is added to increase the number of free charge carriers.

Non-Polar: A non-polarized (non-polar) capacitor is a type of capacitor that has no implicit polarity; it can be connected either way in a circuit.

Ohm: A unit of resistance represented by the symbol:

Ohms Law: The equation used to calculate voltage, current, resistance or power. The law states that the direct current flowing in a conductor is directly proportional to the potential difference between its ends. The equation is written as V = IR.

Open Circuit: A circuit that is broken and current is unable to flow.

Open Position: A switch position that prevents current from flowing.

Operational Amplifier (Op Amp): A voltage amplifier that amplifies the differential voltage between a pair of input nodes. For an ideal operational amplifier, the amplification or gain is infinite.

Oscillator: An electronic circuit that converts energy from a direct current source to a periodically varying electric output.

Oscilloscope: An electronic instrument that measures voltage, frequency and more for waveforms. It produces a display showing two or more variables.

P Type Semiconductor: A semiconductor to which doping material is added to decrease the number of electrons.

Pad: Circuit board contact points.

PN Junction: The interface between two regions in a semiconductor crystal which have been treated so that one is a p-type semiconductor and the other is an n-type semiconductor.

Potentiometer: Manually adjustable, variable, electrical resistor. It has a resistance element that is attached to the circuit by three contacts, or terminals. Also referred to as a pot.

Photovoltaic Cells: Formerly used exclusively in space, photovoltaic cells convert sunlight into electricity. Photo=Light; Voltaic=Electricity

Proton: A positively charged particle.

Prototyping Board: A thin plastic board full of holes used to hold components that are wired together. It is commonly used for prototyping and experimenting with circuit designs and also referred to as a breadboard.

Pulse: A short duration of current flow which rapidly alternates between high and low.

Pulse Width Modulation: A method to control the speed of a motor by turning voltage on and off in rapid pulses. The longer the intervals, the faster the speed of the motor.

R: The symbol for resistance.

RC (resistor/capacitance) time constant: The product of capacitance and resistance in seconds.

Relay: A device that responds to a small current or voltage change by activating switches or other devices in an electric circuit.

Resistance: A measurement of the difficulty encountered by a power source in forcing electric current through an electrical circuit, and hence the amount of power dissipated in the circuit. Resistance is measured in ohms.

Resistor: A component that resists an electric current by producing a voltage drop between its terminals in accordance with Ohm's law.

Schematic: A procedural diagram of an electronic circuit or project.

Semiconductor: A solid material whose electrical conductivity at room temperature is between that of a conductor and that of an insulator. The most significant semiconductor is the transistor.

Sensors: A sensor is a type of transducer. Since a significant change involves an exchange of energy, sensors can be classified according to the type of energy transfer that they detect.

Series Circuit: A circuit in which current runs sequentially through each component.

Short Circuit: An abnormal condition of relatively low impedance, whether accidental or intentional, between two points of different potential in an electric network.

Sine Wave: Wave whose amplitude is the sine of a linear function of time.

Single Pole Double Throw Switch (SPDT): A three-terminal switch or relay contact arrangement that connects one terminal to either of two other terminals.

Single Pole Switch: A switch with one input wire.

Slide Switch: A switch with an actuator that slides forward and backward to turn the device on and off.

Solar Cell: A semiconductor device that converts the sunlight into electric energy. Also referred to as a photovoltaic cell.

Solder Wick: Used to remove solder.

Soldering: The act of using melted solder to connect components together or to circuit boards.

Soldering Iron: The tool used to melt and apply solder.

Solderless Breadboard: A prototyping board that requires no solder to attach the components.

Solid Wire: Wire consisting of a single strand.

Spike: A brief increase in voltage.

Square Wave: A graphic image of a digital pulse as visualized on an oscilloscope. It appears square since it rises quickly to a particular amplitude, stays constant for the duration of the pulse and drops fast at the end of it.

Static Electricity: Static electricity is the form of current that is left within an insulating body after the power source is removed.

Stranded Wire: A group of wires (or combinations of groups of wires) usually twisted together wrapped under insulation.

Stray Capacitance: Undesirable capacitance between circuit wires, between components and the chassis, or between wires and the chassis, in electronic equipment.

Tantalum Capacitors: A kind of capacitor where the anode is a type of tantalum .

Terminal: A position in a circuit or device at which a connection is normally established or broken.

Thermistor: An electrical resistor with a relatively large negative temperature coefficient of resistance. Thermistors are useful for measuring temperature and gas flow or wind velocity.

Thermocouple: A thermoelectric device used to measure temperatures accurately.

Tolerance: The variation in the value of a component due to the manufacturing process. It is expressed typically as a percentage,

Transistor: A small electronic device containing a semiconductor and having at least three electrical contacts, used in a circuit as an amplifier, detector, or switch. A solid-state device involved in amplifying small electrical signals and in processing of digital information. Transistors act as the key element in amplification, detection, and switching of electrical voltages and currents.

Variable Capacitor: Capacitor whose capacitance can be altered by changing the effective area of the plates or the distance between the plates.

Variable Resistors: Also known as potentiometers.

Voltage: The force, or pressure, of electricity. Also known as potential.

Voltage Divider: A number of resistors in series provided with taps at points to make available a fixed or variable fraction of the applied voltage.

Voltage Drop: The difference in voltage from one end of an electrical circuit to the other.

Voltage Regulator: A device or circuit that maintains a load voltage nearly constant over a range of variations of input voltage and load current.

Voltage Spike: Voltage spikes are rapid, quick duration electrical transients in the electric potential of a circuit.

Watt: A unit of power which equals one joule per second.

Watt hour: A unit of electrical energy equal to the work done by one watt acting for one hour and equivalent to 3,600 joules.

Wave Form: The representation of a wave in graph-form achieved by plotting wave against time.

Wire: A usually pliable metallic strand manufactured in many lengths and diameters. It is sometimes clad and often electrically insulated, used mainly to conduct electricity.

Wire Gauge: The system used to measure the diameter of wire.