Glossary

A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
A   [Top]
A 1. Abbreviation for ampere.
2. Symbol for anode.
3. Symbol for argon.
AC abbreviation for alternative current.
Accelerator a video adapter based on a graphics processor designed to speed up video performance. This improvement is accomplished by relieving graphics processing from the system CPU.
AC/DC an abbreviation used to indicate that a receiver or other equipment will operate from either an AC or DC power line.
AC power supply a power supply that provides one or more AC output voltages, such as an AC generator, dynamotor, inverter, or transformer.
Active display a display capable of rapid responses in the visual subject matter being displayed-graphics or alphanumeric characters, usually under electronic control. Examples include cathode ray tubes (CRTs) and active-matrix liquid-crystal, electromunicescent, and plasma panels for the display of graphics and characters for television receivers and computers.
Active Matrix a video display consisting of a matrix with a transistor at each pixel location to store individually the state of the pixel- either on or off. Pixels in active-matrix panels are turned on or off by addressing them. An example is the thin-film-transistor, liquid-crystal display.
A/D Abbreviation for analogue-to-digital, usually used in connection with converters.
Adapter a device that makes electric or mechanical connections between items not originally intended for use together.
A/D converter or ADC Abbreviation for analogue-to-digital converter
Address a unique set of numbers that identifies a particular location in computer memory.
AFC abbreviation for automatic frequency control.
AGC abbreviation for automatic gain control.
Algorithm a set of well defined rules for the solution of a problem in a finite number of steps.
Aligning tool a small screwdriver, socket wrench, or special tool constructed partly or entirely of nonmagnetic materials, used to align tuned circuits.
Alternating current [AC] an electric current that is continually varying in value and reversing its direction of flow at regular intervals, usually in a sinusoidal manner. Each repetition, from zero to a maximum in one direction and then to maximum in the other direction and back to zero, is called a cycle. The number of cycles occurring in 1 s is called a cycle. The number of cycles occurring in 1 s is called the frequency in hertz. The average value of an alternating current is zero. For alternating current terms, see AC entries.
Amplitude The value of a varying quantity at a specified instant.
Analogue monitor a computer monitor that uses continually variable colour control voltages. The use of analogue voltages allows a large number of colours to be displayed.
Angle the measure of the progression of a sine wave in time or space from a chosen instant or position, or the corresponding amount through which the rotating vector of the wave has progressed.
Anode the positive electrode of a two terminal semiconductor device.
ANSI (American National Standards Institute) an organisation that sets standards for languages, database management, etc.
Aperture an opening through which electrons, light, radio waves, or other radiation can pass. The aperture in the electron gun of a cathode-ray tube determines the size of the electron beam. The aperture in a television camera is the effective diameter of the lens that controls the amount of light entering the camera tube. The dimensions of the horn mouth or parabolic reflector determine the aperture if a microwave antenna.
Aperture grille Slot mask
Aperture mask Shadow mask
Architecture describes how a system is constructed and how its components are put together.
ASCII (American Standard Code for Information Interchange) a set of standard codes defining characters and symbols used by computers.
Aspect ratio the ratio of frame width to frame height of a face of a cathode-ray tube for television or a computer monitor. An aspect ratio of 4:3 is typical for a television picture tube or computer monitor, with 16:9 to become more popular every day.
Automatic degausser An arrangement of degaussing coils mounted around a colour television picture tube or display tube, combined with a special circuit that energizes these coils only while the set is warming up after being turned on. The coils demagnetise any parts of the receiver that have been affected by the earth's magnetic field or by the field of any nearby home appliance. Automatic degaussing permits a colour television receiver or a computer monitor to be moved around a home without readjusting purity controls. Also called automatic colour purifier.
AVI (audio-video interleave) the native Microsoft format that combines digital images and images and audio into a composite file that can be distributed or embedded in Windows applications.
B   [Top]
Banana jack a jack that accepts a banana plug. Generally designed for panel mounting.
Banana plug a plug that has a spring-metal tip which somewhat resembles a banana, used on test leads or as terminals for plug-in components
Band a range of frequencies between two definite limits.
Base one of the three leads of a bipolar transistor.
Baseband the frequency band occupied by all the transmitted signals that modulate a particular carrier. The band that transmits picture and synchronising signals in television is one example; another is the band containing all the modulated subcarriers in a carrier system.
Beam a concentrated unidirectional stream of particles, such as electrons or protons.
Bezel a metal or plastic frame fitting over the CRT glass that holds part of the display system together.
BIOS (basic input/output system) a series of programs that handle the computer's low level functions. Video adapters often include their own supplemental BIOS to support high-level video operations.
Bit: binary digit. The basic unit of digital information written as a 0 or a 1.
Bit block transfer (also called BitBlt) a feature of Windows graphics accelation that defines a screen image as a series of pixels that can be moved around quickly and easily.
Black level the level of the picture signal corresponding to the maximum limit of black peaks. This level is generally set t 75% of the maximum signal amplitude of the synchronizing pulses.
Black negative a picture signal in which the voltage corresponding to black is negative with respect to the voltage corresponding to the white areas of the picture.
Blackout a condition of zero voltage on the 120/240 VAC power line due to a failure or deliberate shutdown of the utility's generation and / or transmission facilities.
Black positive a picture signal in which the voltage corresponding to black is positive with respect to the voltage corresponding to the white areas of the picture.
Blank to cut off the electron beam of a cathode ray tube (CRT).
Blanked picture signal the signal resulting from blanking a television picture signal. Adding the sync signal to the blanked picture signal gives the composite picture signal.
Blanketing interference caused by nearby transmitter whose signals are so strong that they override other signals over a wide band of frequencies.
Blanking the process of cutting off the electron beam of a television picture tube, camera tube or cathode ray oscilloscope tube during retrace by applying a rectangular pulse voltage to the grid or cathode during each retrace interval.
Block diagram a diagram in which the principal divisions of an electronic system are indicated by rectangles or other geometric figures, and the signal paths are represented by lines.
Blooming defocusing of television picture areas where brightness is excessive because of enlargement of spot size and halation of the fluorescent screen.
Blower an electric fan that supplies air for cooling purposes.
Bridge an instrument or circuit that has four or more arms, by means of which one ore more of the electrical constants of an unknown component.
Brightness the characteristic of light that gives a visual sensation of more or less light.
Brightness control a control that varies the brightness of the fluorescent screen of a cathode-ray tube (CRT) by changing the grid bias of the tube, thereby changing the beam current.
Boot the process of initialising a computer and loading a disk operating system.
Boot device a drive containing the files and information for a disk operating system.
Buffer a temporary storage place for data.
Bus a collection of digital signal lines within a computer. There might be more than one bus within a computer.
Byte a set of eight bits. A byte is approximately equivalent to a character.
C   [Top]
C 1. Abbreviation for capacitor.
2. Abbreviation for capacitance
3. Abbreviation for Celsius.
4. Abbreviation for coulomb.
Cache memory simply called "cache". Part of a computer's RAM operating as a buffer between the system RAM and CPU. Recently used data or instructions are stored in cache. RAM is accessed quickly, so data called for again is available right away. This functionality improves overall system performance.
Candela the S.I. unit of luminous intensity. One candela is defined as the luminous intensity of 1/60cm2 of a black body radiator operating at the temperature of solidification of platinum. Also called candle.
Capacitance the measure of a device's ability to store an electric charge. The unit of capacitance is the farad (F).
Capacitor an electronic device used to store energy in the form of an electric charge.
Cathode 1. The primary source of electrons in an electron tube. In directly heated tubes the filament is the cathode. In indirectly heated tubes a coated metal cathode surrounds a heater. Other types of cathodes emit electrons under the influence of light or high voltage. 2. The negative electrode of a two terminal semiconductor device.
Cathode ray a stream of electrons, such as that emitted by a heated filament in a tube or emitted by the cathode of a gas-discharge tube when the cathode is bombarder by positive ions.
CCFT (cold cathode fluorescent tube) the light source used in edgelighting liquid-crystal displays so that the display is visible in low light or darkness.
Cell gap the space between two pieces of glass that contains the liquid crystal.
CGA (colour graphics adaptor) a low-resolution graphics mode featuring 320x200 resolution two-colour operation.
Chassis the metal frame on which circuit components are mounted. In monitors, chassis is usually called the printed circuit including all the major electronic circuits. The plural is the same as the singular.
Chassis ground a connection to the metal chassis on which the components of a circuit are mounted, to serve as a common return path to the power source. The chassis may or may not be connected to an earth ground.
Chip carrier a rectangular or square package with I/O (input-output) connections on all our four sides.
Chrominance the difference between any colour and a specified reference colour or equal brightness.
Circuit an interconnected group of active and passive electrical and electronic components that accomplishes a electrical and electronic components that accomplishes a desired function such as switching, amplification, filtering, or data conversion
CMOS abbreviation for complementary metal oxide semiconductor
CODEC (compressor/decompressor) an IC typically used to compress analogue video signals into digital form during video capture, then decompress those digital files for playback.
Coil [L] a number of turns of wire that introduce inductance into an electric circuit, to produce magnetic flux or to react mechanically to a changing magnetic flux. In high-frequency circuits a coil may be only a fraction of a turn. The electrical size of a coil is called inductance and is expressed in henrys. The opposition that a coil offers to alternating current is called impedance and is expressed in ohms. The impedance of a coil increases with frequency.
Collector one of the three leads of a bipolar transistor.
Colour a characteristic of light that can be specified in terms of luminance, dominant wavelength and purity. Luminance is the magnitude of brilliance. Wavelength determines hue and ranges from about 4000 A for violet to 7000 A for red (400 to 700nm). Purity corresponds to chroma or saturation and specifies vividness of a hue.
Colour display a monitor capable of displaying images in colour using three primary color signals (red, green, and blue -sometimes referred to as an RGB monitor.) If 64 levels of each primary colour can be generated, the monitor can be produce 64x64x64 or 262,144 colours.
Colour display tube [CDT] Subcategory of cathode ray tubes CRTs which are designed and manufactured for use in computer monitors supporting VGA-SVGA graphics mode.
Colour picture tube [CPT] Subcategory of cathode ray tubes CRTs which are designed and manufactured for use in television sets, and monitor systems using Horizontal Resolution around 15kHz. CPT has three different phosphor colours. When these are appropriately scanned and excited in a colour television receiver, a colour picture is obtained.
Component any electronic device such as coil, resistor, capacitor, transistor, integrated circuit, or diode that has distinct electrical characteristics and terminals for connecting it to other components to form a circuit.
Composite colour signal the colour picture signal plus all blanking and synchronising signals. The composite colour signal thus includes the luminance signal, the two chrominance signals, vertical and horizontal sync pulses, vertical and horizontal blanking pulses, and the colour-burst signal.
Connection a direct wire path for current between two points in a circuit
Connector a complete connectivity connecting device, that consists of a mating plug and receptacle for cables or of mechanically mating flanges for waveguides
Configuration the components that make up a computer's hardware setup.
Contrast the degree of difference in tone between the lightest and the darkest areas in television or display picture. Contrast is measured in terms of gamma a numerical indication of the degree of contrast. Pictures with high contrast have deep blacks and brilliant whites, and pictures with low contrast have an overall grey appearance
Contrast ratio the difference in luminance between a selected (on) pixel and an unselected (off) pixel.
Convergence in a colour CRT, the alignment of electron beamd such that each will come together at an aperture in the CRT's shadow mask.
Converter 1. A circuit for converting AC power from one frequency to the other.
2. A circuit for converting DC to AC.
3. A circuit for converting AC to DC.
4. A circuit for converting an analogue function to a digital code.
5. A circuit for converting a digital code to an analogue value.
Cord a small, very flexible insulated cable.
Coulomb [C] The SI unit of electric charge. It is the amount of electric charge that passes through a given cross section of a conductor when a steady current of 1 A is flowing
CPU (central processing unit) the primary functioning unit of a computer system. Also called a microprocessor.
CRT (cathode ray tube) generic name for all the tubes that display a picture, a vacuum tube with a wide face coated with phosphor that generates light when bombarded with a focused electron beam. CRTs are the foundation for most PC monitors in service today.
Crystal a natural or synthetic piezoelectric or semiconductor material whose atoms are arranged with some degree of geometric regularity.
Current the flow of electrons or holes measured in amperes (A) or in fractionsof an ampere. Current can be induced by the application of an electric field through a conductor or by changing the electric field across a capacitor (displacement current)
Cutoff the minimum value of bias voltage, for a given combination of supply voltages, that just stops output current in an electron tube, transistor, or other active device.
D   [Top]
Debugging the process of eliminating from a newly designed system the components and circuits that cause early failures.
Deflection yoke an assembly of one or more electromagnets that is placed around the neck of an electron-beam tube to produce a magnetic field for deflection of one or more electron beams. Also called yoke
Degaussing removing magnetism from a CRT or other electronic device
Degaussing coil a coil of wire powered with AC that is used to clear magnetized areas of the CRT.
Diagram a schematic or other line drawing that explains the operation of a circuit or piece of equipment.
Distortion any undesired deviation of an image from proportionality.
DMA (direct memory access) a fast method of moving data from a storage device directly to RAM.
DOS (disk operating system) a program or set of programs that directs the operations of a disk-based computing system.
Dot in a colour CRT, one of the three primary colour phosphors (red, green, or blue). Dots are arranged in a close triangle so that they appear as a single point to the unaided eye.
Drain one of the three leads of a field-effect transistor.
Driver also called a "device driver". A small segment of software that allows application software to take advantage of specialized hardware such as the advanced video modes as the advanced video modes of a video adapter.
Dynamic focusing the process of varying the focusing electrode voltage for a CRT automatically so the electron-beam spots remain in focus as they sweep over the flat surface of the screen.
Dynamic mode switching a system's ability to toggle between several revolution or colour depths in Windows without having to restart Windows.
E   [Top]
Earth English term for ground.
EGA (enhanced graphics adaptor) a medium-resolution graphics mode featuring up to 640x350 resolution, 16 colour operation; commonly available in older applications.
EIA (Electronics Industry Association) a standards organisation in the USA that develops specifications for interface equipment.
EIAJ a Japanese standards organisation that is equivalent of the US Joint Electronic Device Engineering Council (JEDEC).
Electric containing, producing, arising from, or actuated by electricity. Examples are electric energy, electric lamp, and electric motor. It can be used interchangeably with electrical.
Electrical related to or associated with electricity, but not containing it or having its properties or characteristics. It can be used interchangeably with electrical.
Electrolytic capacitor a capacitor whose dielectric is an oxide of aluminum or tantalum. The oxide is formed by electrochemical reaction with those metals. Three styles are wet foil, wet slug and dry or solid slug. Aluminum capacitors are wet-foil style but tantalum capacitors can be made in all three styles. Both aluminum and tantalum units can be polarised or non-polarised. As a class they exhibit high capacitance per unit volume (high volumetric efficiency). An aluminum capacitor can store five or more times as much charge as an equivalent -size film capacitor; a tantalum capacitor can store three times as much charge as an equivalent aluminum capacitor.
Electromagnetic compatibility [EMC] the ability of a device or circuit to function correctly in its intended electromagnetic environment without transmitting unwanted signals to adjacent equipment or receiving unwanted interference from nearby sources.
Electromagnetic shield a metal screen or enclosure placed around circuits to reduce the effects of both electric and magnetic fields. Electromagnetic fields are caused by motors, generators, relays, or devices whose operation depends on alternating fields. Shielding is achieved a reflection or absorption of fields. Reflection occurs at the surface, and it is not usually affected by thickness. Absorption, however, occurs within the shield and is highly dependent on thickness.
Electromagnetic unit [EMU] a CGS unit based on the assignment of unity to the strength of each of two like magnetic poles that repel each other with a force of 1 dyn at a distance of 1 cm in a vacuum.
Electromotive force [EMF] the force that tends to produce an electric current in a circuit. It is usually called voltage.
Electronic circuit a circuit containing one or more transistors, integrated circuits, or other devices providing comparable functions.
Electronics the branch of science and technology that deals with electron devices, including electron tubes, transistors, integrated circuits, and other devices that control the flow of electricity in a vacuum, gas, liquid, semiconductor, etc.
Embedding the process of molding an insulating plastic around a component or assembly to form a solid block having only the leads or terminals exposed.
Emitter one of the three leads of a bipolar transistor.
Encoder a circuit that performs repeated sampling, compression, and analogue-to-digital-conversion to convert an analogue signal to a serial stream of pulse-code modulated (PCM) samples representing the analogue signal.
Epoxy resin A type of synthetic resin (good insulating plastic) that is widely used for encapsulating electronic devices because its properties of high strength and low shrinkage.
EPROM Abbreviation for erasable programmable read-only memory
Ethernet a local area network (LAN) software standard that determines system operation. It is organised with software; network cards and adapters in each computer or terminal in the network
Expansion slot connector a bus that connects an expansion board to the PC. There are several different of busses: ISA, VL, PCI, AGP etc.
Extra-high tension [EHT] British term for the high DC voltage applied to the second anode in a CRT`, ranging from about 4 to 50 kV in various sizes of tubes.
Extra-high voltage [EHV] a voltage above 345 kV when used for power transmission.
F   [Top]
F 1. Symbol for filament. 2. Symbol for fuse 3. Abbreviation for Fahrenheit. 4. Abbreviation for Farad. 5 [f] Symbol for frequency
Fahrenheit [F] temperature scale in which the freezing point of water is 32° and the boiling point of water is 212° at normal atmospheric pressure. Absolute zero is -459.6 °F. To change degrees Fahrenheit to degrees Celsius, subtract 32 and then multiply the result by 5/9 Fahrenheit and Celsius scales agree at on point: -40°F = -40°C. Multiply degrees Celsius by 9/5 and add 32 to get degrees Fahrenheit.
Farad [F] The SI unit of capacitance. A capacitor has capacitance of 1F when a voltage change of 1 V/s across it produces a current of 1 A. The farad is too large a unit for practical work, so two smaller units are generally used. The microfarad is equal to one-millionth of a farad, and the picofarad is equal to one-millionth of a microfarad.
Female connector a connector that has one or more contacts set in recessed openings. Jacks, sockets, and wall outlets are examples of female connectors.
Filament a coil made of resistance wire or ribbon, through which an electric current is sent to produce the high temperature required for emission of electrons in a thermionic tube
File a collection of related information that is stored together on disk.
Film a thin sheet or coating material
Filter a selective device that transmits a desired range of matter or energy while substantially attenuating all other ranges. Thus an electric filter is a network that transmits alternating currents of desired frequencies while substantially attenuating all other frequencies.
Firmware program instructions recorded on a permanent memory device such as PROM or EPROM. BIOS is a typical example of firmware.
Fixed-frequency monitor an analogue monitor that operates using a fixed horizontal sync frequency. Vertical sync frequency might change slightly to accommodate different screen modes.
Flat in CRTs, the degree of flatness of the surface, usually Pure Flat for 100% flat and Real Flat when there is a slight curve (both terms are used by LG-Philips)
Flatpack one of the oldest surface-mount packages with 14 to 50 ribbon leads on both sides of its body.
Flicker a visual sensation produced by periodic fluctuations in light at rates ranging from a few cycles per second to a few tens of cycles per second.
Floating the condition wherein a device or circuit is not grounded and not tied to an established voltage supply.
Flyback transformer a high-energy transformer used to convert horizontal pulse signals into high-voltage that drives the CRT anode, as well as other voltages used within the monitor.
Focus control a control that adjusts spot size at the screen of a cathode-ray tube to give the sharpest possible image. It can vary the current through a focusing coilor charge the position of a permanent magnet
Focus electrode (grid) a CRT electrode that focuses the electron beam(s).
Focusing coil a coil that produces a magnetic field parallel to an electron beam, for the purpose of focusing the beam. The coil is usually mounted on the neck of a cathode ray tube and it carries a direct current
Footprint the form factor and area occupied by a component on a circuit board or substrate
Frequency [f] the number of completed cycles per unit of time for periodic quantity such as alternating current, sound waves. A frequency of 1 cycle/s is 1 hertz (1 Hz).
Fuse a protective device containing a short length of special wire that melts when the current through it exceeds the rated value for a definite period of time. A fuse is inserted in series with the circuit being protected, so it opens the circuit automatically during a serious overload.
Fuse block an insulating base with mounted fuse clips or other contacts for holding fuses.
Fuse diode a diode that opens under specified current surge conditions
G   [Top]
G 1. Symbol for conductance
2. Symbol for gate
3. Symbol for generator
4. Symbol for grid
Gain the increase or decrease of signal amplitude after amplification.
Gate one of the three leads of a field-effect transistor
Ghosting a phenomenon where voltage from an energised element leaks to an adjacent OFF element that seems to turn the OFF element partially ON. An effect typically found in passive matrix LCDs.
Grey scale a series of achromatic tones with varying proportions of white and black, to give a full range of grays between white and black. A grey scale is usually divided into 10 steps.
Grid 1. An electrode located between the cathode and anode of an electron tube with one or more openings through which electrons or irons can pass under certain conditions. A grid controls the flow of electrons from cathode to anode.
2. A network of equally spaced lines forming squares, used for determining permissible locations of holes on a printed-circuit or a chassis.
Ground [gnd] a conducting path, intentional or accidental, between an electric circuit or equipment and the earth, or some conducting body serving in place of the earth. Also called earth (British).
Ground wire a conductor that connects electric equipment to a ground rod or other grounded object.
GUI (graphic user interface) software that allows a user to interact with a program.
H   [Top]
H abbreviation for Henry
Heatsink metal heat radiators designed to remove heat components, particularly power transistors, by thermal conduction, convection or radiation. Heat is conducted away from the internal junction of a semiconductor device to a surface where it can be dissipated. It can be a finned aluminum extrusion, finned copper, or aluminum stampings located under the device case, or aluminum extrusions with radiating fins that clip on the device case. A chamber that is cooled by circulating fluid can also be a heatsink.
Henry the SI unit of inductance. The inductance of a circuit is 1 H when a current change of 1 A/s induces 1 V.
Hercules graphics a video mode that provides bit-mapped, single-colour graphics at a resolution of 720 x 348
Hertz the SI unit of frequency, equal to 1 cycle per second
Horizontal amplifier an amplifier for signals that deflect the electron beam horizontally in a CRT.
Horizontal sync the horizontal synchronisation signal used to time each row of pixels.
I   [Top]
Inductance [L] the measure of a device's ability to store a magnetic charge. The unit of inductance is the henry (H).
Inductor an electronic device used to store energy in the form of a magnetic charge.
Integrated circuit [IC] a monolithic semiconductor device that contains many active components (diodes and transistors) and passive components (resistors, capacitors, and inductors) which function as a complete circuit
Interface a hardware / software connection that links one device to another
Interlace an image displayed by drawing two passes of the electron beam where each pass strikes every other horizontal line
ISO International Standards Organisation
J   [Top]
Jack a connecting device into which a plug can be inserted to make circuit connections. The jack can also have contacts that open or close to perform switching functions when the plug is inserted or removed.
JEDEC (Joint Electronic Device Engineering Council) the United States standards organisation that handles packaging standards.
JEIDA Japanese Electronics Industry Development Association.
Joule [j] the unit of work and energy in the SI. One Joule is the work done by a force of a Newton acting through a distance of 1 mile.
K   [Top]
K 1. Symbol for cathode. 2. Abbreviation for Kelvin 3. Unofficial abbreviation for kiloohm [kΩ]
L   [Top]
LCD (liquid-crystal display) a display technology using a thin layer of liquid crystal sandwiched between two electrodes. An electric field across the liquid crystal causes the crystals to rotate and appear opaque.
LIF (low insertion force) a term used to describe sockets that require only a minimum force to insert or extract an IC.
Local bus an interface bus architecture that provides a faster, more efficient path to the CPU. Devices using a local bus interface are intended to achieve higher performance than conventional ISA bus devices.
Logic analyser an instrument used to monitor signals of an integrated circuit of system.
Luminance the luminous intensity of any surface in given direction per unit of projected area of the surface, as viewed from that direction. The SI unit of luminance is the candela per square meter. It was formerly called brightness.
M   [Top]
Main a line that brings power from generator, converter, or service-cutoff switch to the main distribution centre for power lines inside a building. It is the British term for power line.
Manual 1. used or operated by human action, such as with hands. 2. A reference book, especially one that gives operating instructions.
Mapping the area in computer memory where a particular video mode stores its data. Different video modes store data in different locations.
MCGA (multicolour graphics array) a video mode that provides CGA support with 640x480x2 and 320x200x256 video modes.
MDA (monochrome display adapter) the first video standard defined for the IBM PC.
Monochrome monitor a computer monitor that displays images in a single colour.
Motherboard in a small computer, the main PC board containing the CPU, core memory, most of the system's controller ICs and in some cases, integrated graphics and audio controller
Multi-frequency monitor a monitor that is designed with variable horizontal and vertical sync frequencies. The capability allows the multi-frequency monitor to support a large number of video modes.
N\   [Top]
Neck the small tubular part of the envelope of a CRT, extending from the funnel to the base and housing the electron gun
Noise unwanted low-level electrical interference that is unrelated to the switching of transistors. It is often called "ripple and noise" and can be assigned a peak-to-peak value with a specified bandwidth.
O   [Top]
OEM abbreviation for Original Equipment Manufacturer
Ohm [Ω] The SI unit of resistance and impedance. The electric resistance between two points of a conductor when a constant potential difference of 1 V, applied to these points, produces in the conductor a current of 1 A, the conductor not being the seat of any electromotive force.
OS (operating system) the interface between the hardware and software running on your PC.
Overload a load greater than that which a device is designed to handle. It can cause overheating of the power-handling components and distortion in signal circuits.
P   [Top]
Page a reference to a block of memory (often video memory) in a computer.
Palette a range of colours that are available to be displayed. Only a certain number of the possible colours that can be produced are available at any one time. For example, a monitor that is capable of producing 262,144 colours might only be able to show 256 of those colours at any time.
Parallel port a physical connection on a computer used to connect output devices. Data is transmitted as multiple bits sent together over separate wires. Typically used to connect a printer.
Parity a means of error checking using an extra bit added to each transmitted character.
Passenger Information Display a dedicated monitor displaying information like timetable/departures-arrivals for passengers mainly in airports and rail stations.
Path in printed circuit technology, a conductive strip connecting pads on the surface of one- or two-sided boards or inside a multilayer board, formed by print and etch subtractive methods on copper-foil laminated surfaces, or by plating with additive methods.
Permeable the ability of a material to be magnetized.
Pincushion a form of visual distortion that occurs when a flat image is projected onto a curved surface. Monitor raster circuits are designed to compensate for the distortion.
Pitch also called dot pitch; it is the centre-to-centre dimension between adjacent pixels.
Pixel (picture element) a single visual element of a computer display. On a colour CRT, a pixel is composed of three dots (red, green and blue).
Polarizers sheet material made of polymer acetate incorporated with iodide molecules. The molecules allow scattered light to enter in one plane only. TN LCDs require two polarizers, one in front and one plane only. TN LCDs require two polarizers, one in front and one in back.
POST (power-on self-test) a program in BIOS that handles the computer's initisation and self-test before loading DOS.
Potentiometer a resistor that has a continuously adjustable sliding contact which is generally mounted on a rotating shaft, and used as a voltage diode divider.
Public Information Display a monitor for electronic display of all kinds of information concerning the interest of public. Typical applications include Timetables, Stock Market, Advertisements, News etc.
Pulse a momentary, sharp change in a current, voltage, or other quantity that is normally constant. A pulse is characterised by a rise and a decay and has a finite duration. It also called impulse.
Q   [Top]
Q a figure of merit for an energy-storing device, tuned circuit, or resonant system. It is equal to reactance divided by resistance. The Q of a capacitor, coil, circuit, or system thus determines the rate of decay of stored energy; the higher the Q, the longer it takes for the energy to be released. It is also called Q factor and quality factor.
QWERTY the term for a standard typewriter-style keyboard. The first row of letters begin; Q, W, E, R, T, Y, U, I, etc.
R   [Top]
Rack a standardised steel cabinet that holds 19-inches panels. Originally designed to hold relay panels in telephone exchanges.
Rack-and-panel construction construction of equipment in such a way that all chassis units and panels can be mounted on a standard rack.
Rail voltage British term for supply voltage.
Raster a predetermined pattern of scanning lines that provides substantially uniform coverage of an area.
Refresh rate the number of times each second that the information displayed on a non-permanent display is rewritten. An example is the number of times a CRT image must rewritten or reenergized to remain visible and flicker-free.
Resistance the measure of a device's opposition to the flow of current. The unit of resistance is the ohm (Ω)
Resistor a component used to limit the flow of current in an electronic circuit.
Resolution the ability to delineate, detail, or distinguish between nearly equal values of a quantity. It is a measure of picture image in both vertical and horizontal axes.
S   [Top]
Screen the surface on which a display system is made visible for viewing
Screen electrode a CRT electrode used to regulate overall display brightness.
Semiconductor a class of materials, such as silicon, with electrical properties in between those of conductors (e.g. copper and aluminum) and insulators (e.g. glass and rubber). A material that exhibits relatively high resistance in a pure state and much lower resistance when it contains small amounts of certain impurities. It also denotes electronic devices made from semiconductor materials.
Serial port a physical connection on a computer used to connect output devices. Data is transmitted as individual bits sent one at a time over a single wire. Typically used to connect a modem or a mouse.
Shadow mask a thin film metal plate (placed directly in front of a colour CRT's phosphor face) that blocks stray electrons from exciting nearby colour dots. A slot mask is a variation of the shadow mask.
Slot mask a CRT mask that has vertical slots positioned in front of a screen on which colour phosphors are arranged in vertical stripes. It is in the Trinitron and other tubes that have in-line electron guns. It is also called an aperture grill.
SMT surface-mount technology
Solder 1. an alloy that can be melted at a fairly low temperature, for joining metals which have much higher melting points. An alloy of lead and tin in approximately equal proportions is the solder most often used for making permanent joints in electronic circuits. 2. To join two metals with solder.
Soldering gun a soldering tool that has as its tip a fast-heating resistance element which serves as a short-circuit across high-current, low voltage secondary winding of a step-down transformer built into the unit. A trigger-type switch in a pistol-grid handle permits intermittent use.
Source one of the three leads of a field-effect transistor.
Spark a short duration electric discharge caused by a sudden breakdown of air or some other dielectric material that separates two terminals. It is accompanied by a momentary flash or light.
Spike a short-duration transient whose amplitude considerably exceeds the average amplitude of the associated pulse or signal.
Spot the luminous area produced on the viewing screen of a CRT by the electron beam.
T   [Top]
TFT (thin-film transistor) a fabrication technology used in flat-panel displays where transistors used to operate each pixel are fabricated right onto flat-panel displays.
Transformer [T] a component that consists of two or more coils, which are coupled together by magnetic induction. It can transfer electric energy from one or more circuits to one or more other circuits without change in frequency, but usually with changed values of voltage and current.
Transistor a generic term covering a class of solid state devices that are capable of amplification and/or switching. The two principal categories are bipolar junction transistor (BJT) and field-effect transistor (FET). BJTs are further classified to NPN and PNP and FETs are further classified into junction FETs (JFETs) or metal-oxide semiconductor (MOSFETs). All FETs can be further classified as N-channel or P-channel. A transistor can be discrete device or it can be integrated into an IC.The term also includes the phototransistor and the unijunction transistor.
TTL (transistor-transistor logic) digital logic ICs using bipolar transistors.
TUV Abbreviation for Technische Uberwachungs - Verein Rheinland, a German organisation approved for testing products to the German VDE standards and awarding the Gepruffe Sicherheit (G.S) label. Organisations capable of giving TUV approvals are located in the United States.
V   [Top]
Vertical sync a vertical synchronisation signal used to time each frame (set of horizontal lines).
Video memory an amount of RAM used to store image data to be displayed by a monitor.
Viewing angle a conceptual cone perpendicular to the LCD where the display can still be seen clearly.
VGA (video graphics array) a high-resolution graphics mode featuring 640x480 16-colour and 320 x 200 256 colour resolutions.
Voltage [E] the term most often used to designate electric pressure that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points. Voltage is measured in volts, millivolts, and kilovolts. The terms electromotive force, potential, potential difference, and voltage drop are all often called voltage.
W   [Top]
Watt [W] The SI unit of electric power which in one second gives rise to energy of one joule. In a DC circuit, the power in watts is equal to volts multiplied by amperes. In an AC circuit, the true power is effective volts multiplied by effective amperes, then multiplied by the circuit power factor. There are 746 watts in one horsepower (hp). It is named after the Scottish inventor James Watt, 1736-1819.
Wire a single bare or insulated metallic conductor that has solid, stranded, or tinsel construction, to carry current in an electric circuit.
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