Glossary of Terms
| Term | Definition |
|---|---|
| "C" stage | The condition of a resin polymer when it is in the solid state, with high molecular weight, being insoluble and infusible. |
| C/A | Course/Acquisition (code) |
| cable | Either a stranded conductor with or without insulation and other coverings (singleconductor cable), or a combination of conductors insulated from one another (multipleconductor cable). In fiber optics, a jacketed fiber or jacketed bundle in a form which can be terminated. |
| cable assembly | A completed cable and its associated hardware. |
| cable clamp | A mechanical clamp attached to the cable side of a termination assembly to support the cable or wire bundle. It provides strain relief and absorbs vibration and shock that would otherwise be transmitted by the cable terminations. |
| cable clamp | A device used to give mechanical support to a wire bundle or cable. |
| cable clamp adapter | A mechanical adapter that attaches to the rear of a termination assembly to allow the attachment of a cable clamp. |
| cable modem | Modem designed for use on TV coaxial cable circuit. |
| cable sealing clamp | A device consisting of a gland nut designed to seal around the jacket of a cable. |
| cabler | A machine that mechanically assembles a group of insulated wires. |
| cabling | The act of twisting together two or more insulated components to form a cable. |
| CAD | Computer-aided design. Use of the computer in engineering design activities. |
| calender | Process in which film and sheet material is produced by squeezing heated, viscous material between two or more counter-rotating rolls. |
| CAM | Computer-aided manufacture. Use of computer to aid and direct manufacturing activities. |
| camber | The warpage of ceramic material substrates. It may be in any direction away from the absolute flat condition. Generally measured by passing the slab between two plates of metal, set for maximum allowable camber. |
| campus area network | A network which encompasses interconnectivity between floors of a building and/or buildings in a confined geographic area such as a campus or industrial park. Such networks would not require public rights-of-way and operate over fairly short distances. |
| Canadian Standards Association | CSA - Independent organization that establishes and tests safety standards for electronic components and systems for the Canadian marketplace. |
| CAP | Carrierless Amplitude Phase Modulation. A two-dimensional line code used in ADSL. |
| capacitance | (1) The property of conductors and dielectrics that permits storing electricity when a potential differences exists between conductors. The value of capacitance is expressed as the ratio of the electric charge to the voltage between the conductors. The unit of capacitance is the Farad (F). (2) The ability of an insulation to store electrical energy. This is a function of the permittivity (dielectric constant) of the insulation. Usually expressed in pico farads/foot for a cable. |
| capacitive coupling | The coupling of energy from one conductor to another as a result of the distributed capacitance between them. |
| capacitive decoupling | The establishment of AC ground or a low impedance point for AC signals at a point in a circuit as a result of the presence of capacitance between that point and ground. |
| capacitive reactance | The opposition to alternating current flow presented by a capacitance. The symbol for capacitive reactance is XC. The unit is the ohm. The formula for capacitive reactance is XC = 1/(2ðfC), where f is the frequency of the alternating current signal, and C is the capacitance. |
| capacitor | A device - to store electricity and release it when needed - consisting of conducting plates or foils separated by thin layers of dielectric, the plates on opposite sides of the dielectric layers being oppositely charged by a source of voltage, and the electrical energy of the charged system being stored in the polarized dielectric. A capacitor will block direct current flow but will allow alternating current flow as determined by its capacitive reactance. Often used for filtering or DC blocking. The unit of capacitance is the Farad. |
| CAPs | Competitive Access Provider or Competitive Local Exchange Carrier. Alternative provider to Local Exchange Carrier. |
| Carbonyl Iron | A relatively expensive iron powder used in low permeability, high frequency powdered iron cores. |
| card image | The arrangement of information in memory resulting from computer read-out of a punched card, the information arrangement required for a computer output of a card. A card image is hardware dependent, varying from computer to computer. |
| carrier | (1) A group of strands or ends used to form a finished braid. (2) A higher frequency upon which voice or coded data can be superimposed (modulated). |
| carrier sense multiple access with collision detection | A technique used to control the transmission channel of a local area network to ensure that there is no conflict between terminals that wish to transmit. |
| carrier suppression | The degree to which the carrier signal is reduced in amplitude in a modulator or mixer. Carrier suppression is usually expressed in dB. |
| cascade | To take the output of one amplifier and apply it as the input signal to the second amplifier, and the output of the second to the third, and so on. Each amplifier is called a stage, and stages used successively are said to be in cascade. |
| case | enclosure |
| case temperature | Temperature of the case when the converter and surrounding system are operating normally. Often used as a specification for DC-DC converters with extended temperature ranges. Case temperature is at times referred to as a Base Plate Temperature. |
| catalyst | A substance which initiates and/or accelerates a chemical reaction but normally does not enter into the reaction. |
| catastrophic failure | The complete loss of a device's ability to perform its required function. Most commonly associated with failures that are sudden or involve rapid deterioration. |
| Category 3 | A performance classification for twisted pair cables, connectors and systems.Specified to 16 MHz.Suitable for voice and data applications up to 10 Mbps. |
| Category 5 | A performance classification for twisted pair cables, connectors and systems.Specified to 100 MHz.Suitable for voice and data applications up to 155 Mbps (possibly 1000 Mbps). |
| Category 5e | Also called Enhanced Category 5.A performance classification for twisted pair cables, connectors and systems.Specified to 100 MHz.Suitable for voice and data applications up to 1000 Mbps. |
| Category 6 | A performance classification for twisted pair cables, connectors and systems.Specified up to 250 MHz. |
| cathode | (1) In a semiconductor diode, the terminal to which positive charge carriers flow internally and into which negative charge carriers enter from the external circuit. (2) In electron tubes, the electrode from which electrons are emitted into the inter-electrode space. |
| cathode-ray tube | The "picture tube" found in television receivers, oscilloscopes, and computer and terminal displays. |
| CATV | Community antenna television (cable television) |
| cavity | A metallic enclosure in some types of tubes and circuits within which resonant fields may be excited at the microwave frequency to which the cavity is tuned. Usually referred to as a resonant cavity. (See also contact cavity). |
| CCD | Charge-coupled device. A volatile serial-access memory that stores bits as tiny packets of electric charge moving along the surface of a semiconductor chip. |
| CCITT | Consultative Committee for International Telegraph and Telephone- The former name of an international organization that develops communications standards such as Recommendation X.25. Now called ITU-T. |
| CDI | Course Deviation Indicator |
| CDMA | Code Division Multiple Access. A digital transmission technique based on direct sequence spread spectrum. |
| CDPD | Cellular Digital Packet Data. |
| cellular | A wireless phone system that uses a grid of 'cells', each managed by a base station. Often refers to such systems that operate in or around the 800 - 1,000 MHz band. |
| center fastener | A mechanical fastening device located in the center of mating connectors. Includes a threaded screw on one connector that engages a threaded bushing on the mating connector. |
| centi | A prefix that indicates a factor 10-2, abbreviated as "c.." |
| central processing unit | Abbreviated CPU. The section of a computer that contains the arithmetic, logic, and control circuits. In some systems it may also include the memory unit and the operator's console. Also called main frame. |
| centro-symmetrical reflective optics | An optical technique in which a concave mirror is used to control coupling of light from one fiber to another. |
| ceramic | An insulating material having properties similar to those of glass, notably hermeticity. These inorganic compounds are subjected to heat processing and become vitrified into a solid form. The resultant products are used for film circuits and packaging materials in the form of ceramic substrates. In the RF/microwave industry, the most frequently used ceramic materials are alumina (Al2O3), aluminum nitride (Al3N4), and beryllia (BeO). |
| ceramic cores | One of the common materials used for inductor cores. Its main purpose is to provide a form for the coil. In some designs it also provides the structure to hold the terminals in place. Ceramic has a very low thermal coefficient of expansion, which allows for relatively high inductance stability over the operating temperature ranges. Ceramic has no magnetic properties. Thus, there is no increase in permeability due to the core material. Ceramic core inductors are often referred to as 'air core' inductors. Ceramic core inductors are most often used in high frequency applications where low inductance values, very low core losses, and high Q values are required. |
| ceramic-based microminiature circuitry | Microminiature circuitry printed on a ceramic substrate. Usually consists of combinations of resistive, capacitive, or conductive elements fired on a wafer-like piece of ceramic. |
| cermet | A mixture of materials used to produce high resistance conductors for thick and thin film circuits. |
| CFM | Cubic feet per minute, which is a measure of the volume of air flowing in a system. |
| CGI | Common Gateway Interface |
| chain length | In a linear polymer, the number of monomer structural units. |
| channel | (1) A frequency interval or frequency band assigned for communications. (2) A single path for transmitting electric signals, where the term "path" may refer to separate frequencies or time slots.. (3) The conducting layer in an FET between the source and drain. (4) The entire horizontal cabling system: everything between the computer and the LAN hub in the telecom closet, excluding the equipment connections. |
| character | One of a set of elements which may be arranged in ordered groups to express information. Each character has two forms: (1) a man-intelligible form, the graphic, including the decimal digits 0-9, the letters A-Z, punctuation marks, and other formating and control symbols; and (2) its computer-intelligible form, the code, consisting of a group of binary bits. Codes have been defined using 5, 6, 7, and 8 bit groups. |
| characteristic impedance | The impedance of a transmission line that is independent of length. Also, the ratio of voltage to current at any point along a transmission line on which there are no standing waves. |
| chemical resistance | The ability of an insulation to withstand the presence of materials—such as acids, bases, water, salt water, and fuels—that can deteriorate the insulation, or that, if penetrable to the conductor, can cause dielectric loss of insulating qualities. |
| chemically deposited printed circuit | A printed circuit formed on an insulating base by chemical reaction, providing a conductive pattern. |
| chemically reduced printed circuit | A printed circuit formed by the chemical erosion (etching) of portions of the metallic surface of a metalclad insulative material. |
| Cheminax cables | Raychem’s registered trade name for coaxial cables. |
| chip | A single substrate on which all the active and passive circuit elements are fabricated by semiconductor manufacturing techniques. Its function can be simple or complex. |
| chip carrier | A square semiconductor package having leads on all four sides and on .040 or .050in. centerlines. |
| choke | An inductor which is intended to filter, or 'choke', out unwanted signals. |
| churn | A term used to describe turnover in subscribers of various media such as magazines, newspapers, cable, and videotex services. Churn is an important measures of a medium's success in holding on to customers after they have been signed up as subscribers. |
| circuit | 1) A complete path through which electrons can flow from the negative terminal of a voltage source through a conductor and back to the positive terminal. 2) The interconnected combination of a number of elements or parts to accomplish a desired function (eg filter, oscillator, amplifier). |
| circuit element | A basic constituent of a circuit, exclusive of interconnection. |
| circuit speed | The time taken for a circuit to perform its function - from application of input to resulting output. |
| circuit switching | Switching systems in which a dedicated physical circuit path must exist between sender and receiver for the duration of the "call". Used heavily in the phone company network, circuit switching often is contrasted with contention and token passing as a channel-access method, and with message switching and packet switching as a switching technique. |
| Circuit-Switched Network | Network that establishes a physical circuit temporarily, until it receives a disconnect signal. |
| circular mil area | CMA - A unit of area equal to the area of a circle whose diameter is 1 mil (0.001 inch). Used chiefly in specifying cross-sectional areas of conductors. To obtain the number of circular mils in a round solid wire of a given diameter, express the diameter in mils then square it. The CMA formula for stranded conductor is to square the mil diameter of one strand then multiply by the number of strands. |
| circular mils (cm) | The cross sectional area of a circular conductor calculated as a square conductor (cm is the diameter squared). This is often used in power applications for current handling capability vs. temperature rise. |
| Circulator | A multiport device that propagates signals from one port to the adjacent port with low loss in one direction and with high loss in the opposite direction. |
| cladding | An outer layer on a fiber core which promotes total internal reflection of light and also serves as a protection medium. |
| Cladding mode | A mode confined to the cladding; a light ray that propagates in the cladding. |
| clear | To replace information in a storage device by zero (or blank, in some machines). Also frequently used as being synonymous with "reset" - even in cases where neither memory nor counters are involved. |
| CLEC | A distributed system model of computing that brings computing power to the desktop, where users("clients") access resources from servers. |
| Client/Server | A distributed system model of computing that brings computing power to the desktop, where users("clients") access resources from servers. |
| clock | (1)The device in a digital system which provides the continuous train of pulses used to synchronize the transfer of data. Sometimes referred to as "the heartbeat." (2) Timing pulses used within a system or circuit to synchronize the operation of components. In a DC-DC converter, these pulses are used to synchronize operation of the PWM chips. |
| Clocking | The arrangement of connector inserts, jackscrews, polarizing pins, sockets, keys/keyways, or housing configurations to prevent the mismating or cross-mating of connectors. See also Polarization. |
| Close Magnetic Path | Magnetic core shapes designed to contain all of the magnetic flux generated from an excited winding(s). Inductors made with these core types are considered to be shielded inductors. Shielding, however, is a matter of degree. Common core shapes that are considered to have closed magnetic paths are toroids, E-cores, and most pot cores. Shielded bobbins also offer a high degree of shielding but most have an air gap to some degree. Common core shapes that are considered to have open magnetic flux paths are rod cores and unshielded bobbin cores. |
| closed barrel | The portion(s) of a terminal, splice, or contact that is crimped. When designed to receive the conductor, it is called the wire barrel. When designed to support or grip the insulation, it is called the insulation barrel. Wire and/or insulation barrels may be either "open" or "closed" in design. Closed barrels resemble a hollow cylinder into which the wire must be inserted. Open barrels are formed into an open "U" and are common to most strip terminals manufactured by AMP Incorporated. |
| closed circuit | An electrical circuit through which current can flow, such as when a power switch is moved to the "on" position. The opposite of an "open" circuit. |
| closed end splice | An insulated splice in which two or more wires overlap and all enter the splice from the same end of the barrel. |
| closed entry contact | A female contact designed to prevent the entry of a pin or probing device having a crosssectional dimension (diameter) greater than the mating pin. |
| closed loop | A routine in which a group of instructions is repeated for an indefinite period. |
| Closed Magnetic Path | Magnetic core shapes designed to contain all of the magnetic flux generated from an excited winding(s). Inductors made with these core types are considered to be shielded inductors, although shielding is a matter of degree. Common core shapes that are considered to have closed magnetic paths are toroids, E-cores, and most pot cores. These core shapes do, however, contain minute air gaps that are unavoidable in manufacturing. Some common core shapes considered to have open magnetic flux paths are rod cores and unshielded bobbin cores. |
| CMA | Circular Mill Area - A unit of area equal to the area of a circle whose diameter is 1 mil (0.001 inch). Used chiefly in specifying cross-sectional areas of conductors. To obtain the number of circular mils in a round solid wire of a given diameter, express the diameter in mils then square it. The CMA formula for stranded conductor is to square the mil diameter of one strand then multiply by the number of strands. |
| CMG | Course Made Good |
| CMOS | Complementary-Metal-Oxide-Semiconductor - A popular MOS IC that uses both p-type and n-type material for the channels. This allows very dense packaging and low power consumption. |
| CMTS | cable modem termination system |
| CO | Central Office. A local telephone company office which connects to the main system where circuit switching of customer lines occurs. |
| coax | Short for coaxial. Single-conductor cables with braided shields. Used in the 80's for data transmission. Now generally replaced with UTP for data. Still used for video. |
| coaxial cable | A cylindrical transmission line structure consisting of a central conductor surrounded by a dielectric, which is in turn surrounded by a second, cylindrical conductor (called the shield or outer conductor). The cylinders subtended by center conductor, dielectric and outer conductor all share the same axis. The degree of flexibility in coaxial cables is indicated by the terms, flexible, semirigid, or rigid. |
| coaxial ribbon cable | Ribbon cable consisting of parallel coaxial conductors joined together in a flexible insulating material and designed for mass termination. |
| COBOL | COmmon Business Oriented Language. Used to express problems of data manipulation and processing in English narrative form. |
| Coder/Decoder (Codec) | Equipment to convert between analog and digital information format. Also may provide digital information format. Also, may provide digital compression functions. |
| coefficient of expansion | The fractional change in dimension of a material for a unit change in temperature. |
| Coercive Force (HC) | The value of magnetizing force required to reduce the flux density to zero. |
| COFDM | code orthogonal frequency-division multiplexing |
| co-fire | The process of placing the circuits onto an unfired ceramic, and firing the two (ie the circuits and ceramic) at the same time. Registration for this process is generally toward the center of the slab. |
| COG | Course Over Ground |
| coil | (1) Successive turns of insulated wire which create a magnetic field when an electric current is passed through the wire. (2) Another term for an "inductor". |
| Coil Hi-Pot | The minimum voltage which the relay coil terminals will isolate when the relay is properly mounted. |
| Coil Resistance | The DC resistance, in ohms, of the coil at 25°C. |
| Coils | Another name for inductors. |
| Cold Bend | A test conducted by wrapping tubing or cable around a mandrel or by bending it in an arc while at a low temperature. |
| cold flow | Permanent deformation of polymeric materials (insulation) at ambient temperature due to mechanical force or pressure (not due to heat softening). |
| Cold Impact | A test performed by subjecting a component to a specified impact during exposure to low temperature. It measures the brittleness of the material. |
| cold joint | A soldered joint made with insufficient heat; solder has not completely flowed and wet the substrate. |
| cold weld | A metallurgical bond. The joining of two metals (without an intermediate material) by the application of pressure only - without electrical current or elevated temperature. |
| cold work | Hardening and embrittlement of metal due to repeated flexing action. |
| Collector | The region of a bipolar transistor into which current flows from the base of the transistor under the influence of reverse bias across the two regions. |
| Collector Current | The current that flows through the collector of a bipolar transistor. |
| Color Code | A means of identifying cable components using solid colors or stripes. Also, the scheme that assigns a number from 0 to 9 for each of 10 colors. |
| color coding | The selective placement of color on a terminal or contact to aid in its identification and to assure proper selection of the correct wire size and crimping tool. |
| color concentrates | Pigmented resins with high percentages of pigment. They are mixed with unpigmented resins by the processor. |
| Color Stability | The time and temperature ranges within which the color of a material will remain within the specified color limit. |
| command | A pulse, signal, or set of signals initiating one step in the performance of a computer operation. See also instruction. |
| Common | Conductive path used as a return for two or more circuits. Common is often used interchangeably with ground, which is technically not correct unless it is connected to earth. Also see Ground. |
| Common Carrier | Licensed utility that provides communications services at government-regulated rates. |
| Common Mode Current | A current conduction mode in which currents, present in two or more conductors, are flowing in phase and with equal magnitude within the conductor. |
| Common Mode Filter (or Choke) | An often used type of EMI filter which is wound in such a way that the phasing of the conductors will present a high impedance to common mode current (or noise) while presenting a low impedance to the desired signal. |
| Common Mode Noise | Noise or electrical interference that is common to both electrical lines in relation to ground. |
| Common Mode Noise | Noise component that is common to both the converter output and return lines with respect to the input common. |
| Common Mode Type I | On a single phase Wye bus, the conduction mode in which phase, neutral, and ground currents are in phase. The return current path is through the ground plane and the case. |
| Common Mode Type II | On a single phase Wye bus, the conduction mode in which phase and neutral currents are in phase, but the green wire currents are the return path, thus 180¡ out of phase. |
| Common Mode Voltage | The voltage that drives directed common mode (noise) current. |
| common-mode EMI | Interference that appears between both signal leads and common reference plane (ground) and causes the potential of both sides of the transmission path to be changed simultaneously and by the same amount relative to ground. |
| common-mode impedance coupling | The coupling of energy from one circuit to another that results when two or more currents flow through a common impedance. |
| compiler | A computer program that converts a program in a high-level language such as FORTRAN or Pascal into machine language. |
| complement | The complement of a variable or function is the binary opposite of that variable or function. In binary, if the function is "1," its complement will be "0." |
| component | Any item used in conjunction with another item in its manufacture. |
| compound | Any material composed of more than one element type. |
| Compound Under Strands | CUS - A problem that occurs when loose stranding, or overheating during extrusion, allows compounds to get under individual strands of conductor. |
| Compression | (1) The reduction in expected output power from a device or network that results from saturation of the device as a result of increased input power to the device. (2) The process of eliminating redundancy in a stream of data to represent the data in a more compact manner without destroying the meaning or information contained in the data. |
| compression molding | A method of molding thermosets. Compound (usually preheated) is placed in an open mold, mold is closed, and heat and pressure applied until material is cured. Material melts and flows within the mold to take the shape of the finished part. |
| compression set | The amount of compression an elastomer retains. Expressed as a percentage of original dimensions. |
| computer | Any device capable of accepting information, applying prescribed processes to the information, and supplying the results of these processes. |
| computer, off-line | Auxiliary equipment used with a computing system which operates independently of the main processing equipment, so as not to hamper the computer speed. Typical off-line equipment includes punched-card, punched-paper-tape, and magnetic-tape units. Also, the computer is not actively monitoring or controlling a process. |
| computer, on-line | Major processing equipment of compatible computer speed which is directly connected to the main processing unit. Also, a computer that is actively monitoring or controlling a process. |
| Concentrator | Device that serves as a wiring hub in star-topology network. Sometimes refers to a device containing multiple modules of network equipment. |
| concentric | A central core surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement. Different diameter circles with exactly the same center point. |
| Concentric Stranding | A method of stranding conductor. Specifically, the final conductor is built up in layers so that the inner diameter of a succeeding layer is always equal to the outer diameter of the underlying layer. |
| Concentricity | (1) Ratio (expressed as a percentage) of the thinnest to the heaviest wall thickness. Measured on expanded or recovered tubing, or wire insulation, or jacketing. (2) In a wire or cable, the measurement of the location of the center of the conductor with respect to the geometric center of the circular insulation. |
| Conditioned Analog Line | Analog line to which devices have been added to improve the electrical signal. |
| Conductance | The reciprocal of resistance. The unit of conductance is the siemens, abbreviated as "S." The unit of conductance was the "mho," which was once shown as an upside down capital omega. |
| Conduction Cooled | Cooling a converter via a solid material. Cools a power converter by adding a heat sink or attaching the module to the system chassis. |
| conductive composite | A material comprised of electrically conductive particles dispersed in a polymer binder. |
| conductive fillers | A conductive material added to a dielectric to make it conductive. |
| conductive pattern | The pattern formed from an electrically conductive material on an insulating base (eg the circuit paths on a printed circuit board). |
| conductive plastics | A plastic to which conductive fillers have been added. |
| Conductive Polymer | A dispersion of conductive particles in an insulating organic polymer. |
| Conductivity | The capability of a material to carry electrical current, usually expressed as a percentage of copper conductivity (copper being 100%). Specifically, the ratio of the current flow to the potential difference causing the flow. The reciprocal of resistance. |
| Conductor | A device or material through which current flows easily |
| Conductor Resistance | The resistance to flow of the electrical current along a conductor. Expressed in ohms/1000 feet. (Usually referenced to 20°C). |
| Conduit | A tubular raceway for holding wires or cables. |
| Configuration | Arrangement of contacts in a multiple-contact connector. |
| confined (C) crimp | A crimp that remains in the confines of the outside diameter of the original barrel. (See also confined crescent crimp). |
| confined crescent (CC) crimp | A crimp that remains within the confines of the outside diameter of the original barrel, and is usually identified by two crescent (moon) shaped forms on the top and bottom of the wire barrel crimp. |
| connector | A coupling device employed to connect conductors of one circuit with those of another circuit. Used to provide rapid connect/disconnect mating with a pc board, posts, or another connector. A housing becomes a connector when it contains the specified number of contacts (with conductors) to make it functional. |
| connector assembly | Includes more parts than just a housing and contacts. It usually consists of a housing (with contacts), or a shell (with modules or inserts and contacts), and the necessary hardware to hold the assembly together and/or make the assembly a functional connector. |
| Connector Classes | Categories based on shape, function, and smallest-size contact in a series. |
| Connector Insert | In connectors with metal shells, the part that holds contacts in proper arrangement while electrically insulating them from each other and from the shell. |
| Consolidation point | An interconnect device that allows the horizontal cable to be split into two parts.Used for zone cabling. |
| Contact | The element in a connector that makes the actual electrical connection. Also the parts of a connector that actually carry the electrical current, and are touched together or separated to control the flow. |
| contact alignment | See contact float. |
| contact area | When conductors, electrical contacts, and/or printed circuit boards are joined electrically, "contact area" defines the actual amount of surface area through which current is free to pass from one to the other. |
| Contact Arrangement | All Kilovac relays are one of the following: single pole single throw (SPST); single pole double throw (SPDT); double pole double throw (DPDT); four pole double throw (4PDT) |
| contact bounce | The intermittent and undesired opening of closed contacts or closing of open contacts that occurs during relay operate and release times. |
| Contact Capacitance | Contact capacitance is measured either between open contacts or between contacts and ground. Measurements are made per MIL-STD-202, Method 305, at 1 kHz. |
| contact cavity | A defined hole in the connector insert or housing into which the contact must fit. |
| Contact Crimp | A contact whose rear portion is a hollow cylinder that accepts the conductor. A crimping tool is applied to swage or form the contact metal firmly against the conductor. Sometimes referred to as a solderless contact. |
| contact durability | The number of insertion and withdrawal cycles that a connector must be capable of withstanding while remaining within the performance levels of the applicable specification. |
| contact engaging and separating force | Force required to either engage or separate contacts - both in and out of the connector housing or insert. Values are generally established for maximum and minimum forces. Performance acceptance level vary per specification or customer requirements. Sometimes the forces are not only measured initially, but also after specified number of engagements and separations. |
| contact float | Defines the overall side play which contacts shall have within the contact cavity of a connector housing, to permit self-alignment of mating contacts. Sometimes referred to as contact alignment. |
| Contact Form | All Kilovac relays are one of the following: Form A: SPST-Normally Open; Form B: SPST-Normally Closed; Form C: SPDT; Form 2C: DPDT; Form 4C: 4PDT; Form P: SPST-Latching; Form R: SPDT-Latching; Form X: SPST-NO-Double Make; Form Y: SPST-NC-Double Break |
| contact inspection hole | A hole, perpendicular to the cylindrical rear portion of screw machine contacts, used to check the depth to which wire has been inserted into the wire barrel. |
| contact rating | The maximum specified voltage and current to be passed through a set of contacts. |
| contact resistance | (1) Measurement of electrical resistance of mated contacts when assembled in a connector under typical service use. Electrical resistance is determined by measuring from the rear of the contact area of one contact to the rear of the contact area of its mate (excluding both crimps) while carrying a specified test current. Overall contact resistance would be the wire to wire measurement. (2) In vacuum relays, the resistance of closed contacts is measured as voltage drop across contacts carrying 1 amp at 6 Vdc. Measurement is made in accordance with MIL-R-83725, SAE ARD 50031, or MIL-R-6106. In gas-filled relays, 1 amp at 28 Vdc is used to measure contact resistance. “Kelvin” connections should be used to obtain accurate readings. |
| contact retention | Defines the minimum axial load in either direction which a contact must withstand while remaining firmly fixed in its normal position within the connector insert or housing. |
| contact shoulder | The flanged or enlarged portion of a contact that prevents it from being over inserted into the appropriate contact cavity. The shoulder may also contribute to proper orientation and stability with the connector housing. |
| contact size | Defines the largest wire size which is normally used with the specific contact. By control document dimensioning, it also defines the size of the engagement end of the pin contact. |
| contact spacing | The distance between the centers of contacts within a connector insert or housing. |
| contact spring | The spring placed inside a sockettype contact to force the pin into positive intimate contact. Various types are used - depending on the application - including: leaf, cantilever, napkin ring, squirrel cage, hyperbolic, and "chinese finger" springs. All perform the function of wiping and establishing good contact. |
| contact wipe | The distance over which the mating contact surfaces are touching during engagement and separation. (See also wiping action). |
| contact, bellows | A contact in which a flat spring is folded to provide a uniform spring rate. AMP considers cantilever spring construction to be superior to bellows because the insertion forces of the cantilever are desirably less. |
| contact, two-piece | A contact made of two separate parts joined by swedging, brazing, or other means of fastening to form a single contact. While this provides the mechanical advantages of two metals, it also has the inherent electrical disadvantage of difference in conductivity. |
| contents | The information contained in any storage medium. |
| continuity | A continuous path for the flow of current in an electrical circuit. |
| Continuous Current | The maximum current that can be carried by the closed contacts of the relay for a sustained time period. This specification is determined by measuring the resis-tance heating effect on critical relay components and must be derated at RF frequencies. |
| Continuous Operating Temperature | Maximum temperature at which a component will maintain an acceptable lifetime performance, based on accelerated aging prediction. |
| Continuous Service | Conditions (time, temperature, environment) that describe the lifetime requirements of a component. |
| Continuous Shield | See six-sided shielding. |
| Continuous Wave | The state of operation in which there is no interruption of the presence of a signal. The succeeding cycles of a continuous wave are identical. |
| control unit | The portion of a computer which directs automatic operation, interprets computer instructions, and initiates the proper signals to the other computer circuits to execute instructions. |
| Control Winding | The winding on a mag amp or saturable reactor used to control the amount of magnetic energy the core will absorb before saturating. |
| controlled part | An item which requires the application of specialized manufacturing and/or procurement techniques. |
| controller | An instrument that holds a process or condition at a desired level or status as determined by comparison of the actual value with the desired value. |
| Convection Cooled | Cooling of a converter via the movement of air over the surface of its heat dissipating components. Free-air convection means that the natural movement of air (unassisted by a fan or blower) is sufficient to maintain a converter within specified operating limits. |
| Conversion Loss | The reduction of signal power as a result of the conversion from the signal frequency to the IF frequency by a down converting mixer. Since this is defined as a loss, a reduction in power is considered as a positive conversion loss. LC = (IF output power)/(signal input power). Conversion loss can also be expressed in dB: L (dB) = -10 log (PIF/ PRF). When referring to a mixer diode, conversion loss is the loss in an optimum single-ended mixer carefully designed to minimize losses in the RF and LO coupling networks. Conversion loss normally includes power transferred to the image frequency that is resistively terminated. |
| copolymer | A compound resulting from the polymerization of two different monomers. |
| Copper Loss | The power lost by current flowing through the winding. The power loss is equal to the square of the current (I) multiplied by the resistance (R) of the wire (I2R). This power loss is realized in the form of heat. |
| Copper Loss | The power lost by current flowing through the winding. The power loss is equal to the square of the current multiplied by the resistance of the wire (1^2*R). This power loss is transferred into heat. |
| CopperOptics | A PairGain trademark referring to the functionality of the company's xDSL technology. In essence, with PairGain xDSL products, users can achieve fiber optic-quality signal transmission over copper cable. |
| cordwood | The technique of producing modules by bundling parts as closely as possible and interconnecting them into circuits by welding or soldering leads together. |
| Core | (1) In cables, a component or assembly of components over which additional components, such as a shield or a sheath, are applied. (2) Inner wall of dual-wall heat-shrinkable tubing. (3) Magnetic material placed within and around a coil to provide a path of lower reluctance for magnetic flux. (4) The central, light-carrying part of an optical fiber; it has an index of refraction higher than that of the surrounding cladding. |
| Core Constant | The summation of the magnetic path length of each section of the magnetic circuit divided by the square of the corresponding magnetic area of the same section. |
| Core Losses | Core losses are caused by an altering magnetic field in the core material. The losses aer a function of the operating frequency and the total magnetic flux swing. The total core losses are made up of three main components: Hysteresis, eddy current and residual losses. These losses vary considerably from one magnetic material to another. Applications such as higher power and higher frequency switching regulators require careful core selection to yield the highest inductor performance by keeping the core losses to a minimum. |
| Core Saturation | The DC bias current flowing through an inductor which causes the inductance to drop by a specified amount from the initial zero DC bias inductance value. Common specified inductance drop percentages include 10% for ferrite cores and 20% for iron powder cores in energy storage applications. Also referred to as saturation current. |
| 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. |
| corona | A discharge of electricity appearing as a bluish-purple glow on the surface of, and adjacent to, a conductor when the voltage gradient exceeds a certain critical value. It is due to the ionization of surrounding air by high voltage. |
| counter | A device which maintains a continuous count of the events or pulses which are sequenced through, received, or sent. The word "counter" is sometimes used improperly as a synonym for scanner or multiplexer. |
| Coupler | A class of multiport components that directs the majority of an incident signal to the output port and the remainder of the signal to other ports. |
| Coupling Factor | The ratio of the input power of a coupler to the output power from the coupled port. Coupling factor is typically expressed in decibels (dB). |
| Coupling Ring | The portion of a plug that aids in the mating and demating of a plug and receptacle and holds the plug to the receptacle. |
| coupon | A specimen of a printed board, or of printed-board material, for testing purposes. |
| Cover, Electrical Connector | An item specifically designed to cover the mating end of a connector for mechanical and/or environmental protection. Also known as a dust cover. |
| Coverage | A calculated percentage that defines the completeness with which a braid or shield covers the surface of the underlying insulated conductor or conductors. |
| CPE | Customer Premises Equipment-Terminating equipment, such as terminals, phones, routers and modems, supplied by the phone company, installed at customer sites, and connected to the phone company network |
| CPU | Central Processing Unit - The section of a computer that contains the arithmetic, logic, and control circuits. In some systems it may also include the memory unit and the operator's console. Also called main frame. |
| creep | Any slow change in a dimension or characteristic when a constant stress is applied to a material over a given period of time. Also referred to as cold flow. |
| creepage | The conduction of electricity across the surface of a dielectric. |
| creepage path | The path across the surface of a dielectric between two conductors. Lengthening the creepage path reduces the possibility of arc damage or tracking. |
| crimp | The final configuration of a terminal barrel after the necessary compression forces have been applied to cause a functional union between the terminal barrel and wire. |
| crimp contact | An electrical terminal or contact having a wire barrel that has been formed or machined into a hollow cylinder or left to remain as an open "U." After a wire has been inserted, the barrel is swedged into a controlled form that will continue to exert pressure on the wire. A crimp contact is often referred to as a solderless contact. |
| crimp height | A top to bottom measurement of the crimped barrel, using a Crimp Height Comparator in the prescribed manner. Refer to Instruction Sheet IS 7424. |
| crimper | The term most commonly used within AMP to identify that part of the crimping die - usually the moving part - which indents or compresses the terminal barrel(s). Also called indenter. |
| crimping chamber | The area of a crimping tool in which a contact or terminal is crimped; the crimping enclosure formed by the mating of the anvil (nest) and crimper (indenter). When the dies or jaws are fully closed or bottomed, it is the crimping chamber that is checked with a go no-go plug gage to ensure that the crimp produced by the tooling satisfies the crimp height specification. See also die closure. |
| Crimping Die | Portion of the crimping tool that shapes the crimp. |
| crimping dies | A term most commonly used within AMP to identify the shaping tools that when moved toward each other, produce a certain desirable form to the barrel of the terminal or contact that has been placed between them. Crimping dies for open barrel terminals are usually referred to as "crimper and anvil." Die set components used to crimp closed barrel terminals of the loose-piece variety may be referred to as "indenter and nest," "moving die and stationary die," or "male die and female die." Die sets are sometimes also referred to as die inserts. |
| crimping head | Tooling containing jaws and linkage for use in pneumatic or hydraulic powered units to crimp loosepiece contacts/terminals that may be too large for hand tool applications. |
| crimping tool | A term most commonly used to identify a hand held mechanical device (hand crimping tool) that is used to crimp a contact, terminal, or splice. |
| Critical Rate of Rise of Off-State Voltage | Maximum voltage rate of rise that will not cause a SiBar device to turn on. |
| Critical Rate of Rise of On-State Current | Maximum current rate of rise a SiBar device can withstand without damage. |
| Cross connect (XC) | Connecting hardware used to patch between two groups of cables (horizontal to backbone, for example).AMP 110Connect XC. |
| cross crimp | A crimp that deforms the terminal by exerting pressure on the top and bottom of the terminal barrel without confining the sides. Usually identified by a raised crescent (moon) shaped form on the surface of the crimp. |
| Cross Regulation | For a multiple output converter, the change in voltage on one output (expressed as a percent) caused by a load change on another output. |
| cross-linked | Inter-molecular bonds between long chain thermoplastic polymers by chemical or electron bombardment means. The properties of the resulting thermosetting material are usually improved. |
| Crosslinking | The formation of bonds between molecular chains in a polymer by means of chemical catalyzation or electron bombardment. The properties of the resulting thermosetting material are usually improved. |
| Crosslinking by Irradiation | A method of crosslinking polymers that makes a nonflowing material. This generally improves the properties of the polymer. |
| crossover | The point at which two conductors - insulated from each other - cross. |
| crosstalk | A magnetic or electrostatic coupling which causes the unwanted transfer of energy from one circuit, called the disturbing circuit, to another circuit, called the disturbed circuit (eg, voice communication heard in a given circuit, but originating in an adjacent circuit). |
| Crowbar | Circuit that crowbars or rapidly shuts down a converters output if a preset voltage level is exceeded. The circuit places a low resistance shunt across the output when an overvoltage condition exists. |
| CRT | cathode-ray tube. |
| CRT display | A computer terminal presenting visual data readout on a cathode-ray tube. |
| crush crimp | A crimp used on small contacts with small wire sizes. The wire barrel is preformed with the tips flared outward. During the crimping process, the flared tips slide around the crimper until the wire barrel closes, and then, the tips fold down and away from the center seam. |
| Crystallinity | The portion of polymer chains that are ordered in a regular (as opposed to amorphous) structure or a crystal lattice. Crystallinity tends to improve mechanical properties and fluid resistance. Crystalline or semicrystalline materials have a well-defined melting point (shrink temperature) at which the structure becomes disordered and the polymer flows. |
| CSA | Canadian Standards Association. A nonprofit, independent organization which operates a listing service for electrical and electronic materials and equipment. The Canadian counterpart of the Underwriters Laboratories. |
| CSMA/CD | Carrier sense, multiple access, with collision detection. A technique used to allocate and control the communication channel of a local area network and ensure there is no conflict between nodes that wish to transmit. |
| CSR | Centro-symmetrical reflective optics. |
| CSU/DSU | Channel Service Unit/Data Service Unit- A digital interface unit that connects end user equipment to the local digital telephone loop. |
| Cuk Converter | Variation of the "buck-boost" converter that produces very low output ripple. Used primarily in applications that do not require input/output isolation. Also see Flyback Converter. |
| cure | To change the physical properties of a material by chemical reaction, by the action of heat and catalysts, alone or in combination, with or without pressure. |
| Curie Temperature | The temperature at which a ferrite material loses its magnetic properties. The core's permeability typically increases dramatically as the core temperature approaches the curie temperature, which causes the inductance to increase. The permeability drops to near unity at the curie temperature, which causes the inductance to drop dramatically. The curie point is the temperature at which the initial permeability (µi) has dropped to 10% of its value at room temperature. |
| Curing | Application of heat to thermoset material to harden or set the material; once set, cannot be resoftened by heating. |
| curing agents | Agents added to accelerate the reaction or curing of thermosetting plastics. They act as catalysts; ie, they do not react directly with the polymer in the polymerization. Crosslinking agents are distinguished from catalysts because they react with molecules and are coupled directly into the cured system as a structural member of the polymer. |
| curing cycle | The time, temperature, and pressure required for curing. |
| current | The rate of transfer of electricity from one point to another. Current is usually a movement of electrons but may also be a movement of positive ions, negative ions, or holes. Current is measured in amperes, milliamperes, and microamperes. |
| Current Density | The amperes per unit of cross section in the conductor. This is commonly measured in circular mils per amp (cm/a). |
| Current Foldback | See foldback current limiting. |
| current gain | In a transistor, the ratio of output to input current under specified conditions. |
| Current Limit | Maximum steady-state current level at which the power switch output is regulated in response to an overcurrent fault. |
| Current Limit Knee | On a plot of output voltage vs current, the point at which current begins to limit (or foldback). |
| Current Limiting | Feature that protects the converter (or load) from damage under overload conditions. The maximum converter output current is automatically limited to a predetermined safe value. If the converter is specified for auto restart, normal operatoin is automatically restored when overload condition is removed. |
| Current Mode Control | Control method used with switching converter topologies. A dual loop control circuit adjusts the PWM operation in response to a measured output current. |
| Current Rating | The maximum continuous electrical flow of current for which a device is designed to conduct for a specified time at a specified operation temperature. Usually expressed in amperes. |
| Current Transformer | Usually used in a sensing device, current transformers customarily have a one turn primary. The number of secondary turns is determined by the sensitivity required and is terminated with a resistor. Toroidal in shape, cores of silicon steel, nickel alloy, or ferrite are used. Choice of core material influences cost and accuracy. |
| Current,Hold | The largest steady state current that, under specified ambient conditions, can be passed through a PolySwitch device without causing the device to trip. For SiBar devices, the current at which the device resets to a high-impedance state once the surge current dissipates. See also Hold Current. |
| Current,Maximum Interrupt | The highest fault current that can safely be used to trip a PolySwitch device under specified conditions. Typically the lower the voltage dropped across the PolySwitch device in its tripped state, the higher the maximum interrupt current. Maximum interrupt currents are usually shown in this Databook at the maximum voltage. It may be possible to use a PolySwitch device at a higher interrupt current, but each such use must be individually qualified. |
| Current,Normal Operating | The highest steady state current that is expected to flow in a circuit under normal operating conditions. At the maximum ambient operating temperature of the circuit, the hold current of a PolySwitch device used to protect the circuit is typically greater than the normal operating current. |
| Current,Operating Range | The range of normal operating currents in a circuit containing a PolySwitch device. Typically the hold current of the PolySwitch device should be greater than the top of the operating current range. |
| Current,Trip | The smallest steady state current that, if passed through a PolySwitch device, will cause the device to trip, under specified conditions. |
| Current-carrying Capacity | The maximum current an insulated conductor is capable of carrying without exceeding its insulationand /or jacket-temperature limitations under specified ambient conditions. Also known as ampacity. |
| current-mode logic | CML - A bipolar logic family that works by diverting current from one path to another, rather than by switching transistors on and off. Characterized by very fast operating speeds and high power dissipation. Also called emitter current logic (EML). |
| CUS | Compound Under Strands - A problem that occurs when loose stranding, or overheating during extrusion, allows compounds to get under individual strands of conductor. |
| cutoff frequency | fc - The frequency at which the filter provides 3 dB of loss (1/2 power). |
| cutoff tab | On strip terminals, the projection which results when the point-of-shear is not flush with the terminal body. |
| Cutoff wavelength | For a single-mode fiber, the wavelength above which the fiber exhibits single-mode operation. |
| Cutout | The hole, usually round or rectangular, cut into a metal panel in order to mount a connector. The cutout may also include holes for mounting screws or bolts. |
| Cut-through Resistance | Resistance of solid material to penetration by an object (typically a closely controlled knife edge) under conditions of pressure, temperature, and other elements. |
| CW | Continuous Waves - The state of operation in which there is no interruption of the presence of a signal. The succeeding cycles of a continuous wave are identical. |
| cycle | One complete sequence of values of an alternating quantity, including a rise to maximum in One direction, and return to zero, a rise to maximum in the opposite direction, and return to zero. the number of cycles occurring in One second is called the frequency. |
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