The Illustrated Dictionary of Electronics - Loscha

400 laser disk • laue diagramOutput+EndmirrorSubstrate andheatsink−laser diodeP-typematerialN-typemateriallaser disk A method of reproducing sound inwhich a laser is used to recover the sound from acompact disk.laser Doppler radar Acronyms, ladar or lopplar. Aform of Doppler radar using the light beam of alaser instead of radio waves.laser eye surgery A method of repairing the retinaof the eye without cutting the eyeball, using laserbeams to push loose retina tissue back intoplace.laser gun A colloquial term for a weapon thatmakes use of a laser as a device of destruction.laser optical videodisc system A system in whicha low-powered laser reads audio and video informationfrom a videodisc and delivers it to a televisionreceiver.laser ranger A radar-like device using intense light(instead of microwaves).laser show A three-dimensional, midair displayhaving motion, made by using lasers in variouscombinations.laser surgery The application of a laser inmedicine for the purpose of assisting in, or actuallyperforming, operations on human subjects.laser welding Welding (especially of tiny pieces)with the heat produced by a laser beam.lasing The emission of coherent electromagneticenergy in the visible-light spectrum. See LASER.lat Abbreviation of LATITUDE.latch 1. A feedback loop in a symmetrical digitalcircuit, such as a flip-flop, used to maintain agiven state. 2. A simple logic-circuit storage elementthat consists of two gates as a unit. 3. Tomaintain a closed (energized) state in a pair of relaycontacts after initial energization from a singleelectrical pulse. See LATCHING RELAY.latching current In a thyristor, the minimumvalue of anode current (slightly higher than theholding current) that will sustain conduction immediatelyafter switch-on.latching relay An electromechanical or fully electronicrelay that locks into whichever mode it isenergized for (on or off).latch-on relay See LOCKING RELAY.latchup In a transistor switching circuit, the abnormalcondition in which the collector voltageremains at its switched-on level after the transistoris switched to cutoff from saturation.latch voltage The input voltage at which a flip-flopchanges states.late contacts Relay contacts that are operated followingthe movement of other contacts during therelay’s operation.latency 1. The time taken by a digital computer todeliver information from its memory. 2. In a serialstorage system, the access time less the wordtime.latent image 1. In a storage tube, a stored imagethat is not yet visible. 2. An image stored in the mosaicof an iconoscope. 3. The image that will appearwhen photographic film or paper is developed.lateral chromatic aberration An aberration affectingthe sharpness of off-axis color televisionimages.lateral compliance In phonograph reproduction,the ease with which the stylus can move laterallyas it follows the groove. Also see COMPLIANCEand LATERAL RECORDING.lateral-correction magnet In a color picture tube,a magnet operated with a set of pole pieces attachedto the focus element of the blue gun; itcontrols horizontal positioning of the blue beamfor convergence.lateral magnet See LATERAL-CORRECTIONMAGNET.lateral recording A disc recording in which thegroove undulates from side to side. CompareVERTICAL RECORDING.latitude Abbreviation, lat. Angular distance measuredaround the earth’s circumference to thenorth and south from the equator. CompareLONGITUDE.latitude effect The tendency of the earth’s magneticfield to decrease the number of chargedsubatomic particles that reach the surface of theearth near the equator, as compared with thenumber reaching the surface at other latitudes.Latour alternator See BETHENOD ALTERNATOR.lattice 1. The orderly internal pattern (matrix) ofatoms in a crystal. Also see CRYSTAL LATTICE.2. A symmetrical arrangement of components ina network (such as an attenuator, a filter, or abridge circuit).lattice filter A lattice network having reactance inits arms that makes it a selective circuit.lattice network See LATTICE, 2.lattice section See LATTICE, 2.lattice structure See LATTICE, 1.lattice winding See UNIVERSAL WINDING.laue diagram A pattern of spots on a photographicplate produced by the scattering of high energyradiation as it falls on a thin crystal. This patternis used to determine the nature of the crystalmaterial.