The Illustrated Dictionary of Electronics - Loscha

fader • fan-out 275tomotive high-fidelity sound system, a controlthat adjusts the volume of the front speaker setand rear speaker set. Usually, this is a singleknob; increasing the front volume decreases therear volume, and vice-versa.fading 1. Repeated increases and decreases of radiocommunications signal amplitude at the receptionpoint. Fading of a radio wave results frommultiple propagation paths from transmitter toreceiver, causing the received waves to arrive inconstantly varying phase relationships. 2. In acell or battery power supply, a gradual loss ofpower-delivering capability that occurs duringthe discharge cycle.TXEarthfadingIonizedlayerRXcent to 10 percent of its peak amplitude. CompareRISE TIME.false add A logic add (i.e., addition without carries).false alarm 1. Improper operation of an electronicsecurity system, resulting in actuation of thedevice when no breach of security has occurred.2. In radar, the presence of a false echo thatcauses the attendant circuits or personnel to actas though an enemy target is present.false error A condition in which a computer systemerroneously signals the existence of an error.false precision See MISLEADING PRECISION.false retrieval The incorrect specification of criteriafor information to be selected for retrieval sothat an unwanted item of data is selected. Alsocalled false drop.family Any group of components, circuits, ratings,or characteristics, classed together because ofsome common or analogous feature or application.Examples: IC family, family of curves, andfamily of equations.family of curves A group of curves plotted on thesame axes, that depict the performance of a circuitor device at several levels of a third parameter (e.g.,curves showing transistor collector current vs. collectorvoltage for several levels of base current).Collectorcurrent,milliamps8_6 _4 _2 _0 ____0 51015Collector voltage, voltsfactory automation The use of robotic devices, tothe greatest extent possible, as laborers in manufacturingplants.Fahnestock clip A flat, sheet-metal spring clip forholding a wire (usually in a temporary breadboardsetup).Fahrenheit scale A temperature scale on whichthe freezing point of water is 32 degrees, and theboiling point of water is 212 degrees. CompareABSOLUTE SCALE and CELSIUS SCALE.failsafe Pertaining to devices or circuits that, uponfailure, cause no damage or serious malfunction.failsoft In a computer, a system in which operationis maintained—even in the event of partial failure.Efficiency is reduced but the computer doesnot completely shut down.failure The condition wherein a circuit, system, ordevice is not operating correctly.failure analysis 1. The process of determining thefailure rate for a component, system, or device.2. The process of determining the cause of afailure.failure mode The particular way in which a failureof equipment or a method occurs.failure unit A unit of machine or device failure:one failure per billion (10 9 ) hours of operation.fall-in The time when synchronous speed is attainedin a synchronous motor.falling characteristic A NEGATIVE RESISTANCEcharacteristic.fall time 1. Decay time. 2. The time required forthe amplitude of a pulse to decrease from 90 perfamilyof curvesBasecurrent,microamps15010050250_fan antenna See DOUBLE-V ANTENNA.fan-in 1. A number of inputs entering a commoninput terminal. 2. In digital computer operations,the number of inputs that can be accommodatedby a logic circuit. Compare FAN-OUT.fan-in circuit A circuit having a number of inputlines entering a common input point. Also seeFAN-IN, 1.fan-out 1. One common output terminal feeding anumber of output lines. 2. In digital computer