Product Guide

The following list of manufacturers and suppliers is intended as a guide for the reader and gives some companies who produce items under the headings given. It is not intended to be a comprehensive listing of any one product.

Capacitors Advance Filmcap Ltd Bosch Ltd Britimpex Ltd A F Bulgin & Co Ltd Cambion Electronic Products Ltd Daly (Condensers) Ltd Dubilier Condenser Co (1925) Ltd Electrautom Ltd Electroustic Ltd Electrosil Ltd Emihus Microcomponents Ltd English Electric Valve Co Ltd ERG Industrial Corporation Ltd Erie Electronics Ltd G E Electronics (London) Ltd Guest International ltd Hawnt & Co Ltd A H Hunt (Capacitors) Ltd I RC Components Ltd ITT Components Group (Capacitor Division) lmpectron Ltd London Electrical Manufacturing Co Ltd Macro- Marketing Ltd Matthey Printed Products Ltd Mullard Ltd Oxley Developments Company Ltd Pedoka Ltd The Plessey Co Ltd (Components Group) Radiosparas RIC Capacitors Ltd Salford Electrical Instruments Ltd Siemens (United Kingdom) Ltd Sprague Electric (UK) Ltd

161 Techmation Ltd ERG Industrial Corporation Ltd Telephone Manufacturing Co Ltd Elden Electronics Ltd Townsend-Coates Ltd Electro-Voice Products Union Carbide UK Ltd Ferranti Ltd Vitramon Europe Foster Transformers Ltd Waycom Ltd Gardners Transformers Ltd Wego Condenser Co Ltd Gresham Transformers Ltd Hinchley Engineering Co Ltd Howells Radio Ltd Resistors and Potentiometers ITT Components Group Europe A B Electronic Components Ltd ITT Components Group Europe Alma Components Ltd (Rectifier Product Division) B & K Instruments Ltd Lambda Electronics A F Bulgin & Co Ltd Litton Precision Products C G S Resistance Co Ltd Mullard Ltd Colvern Ltd Parmeko Ltd Cressall Manufacturing Co Ltd Pedoka Ltd Davies Integrated Sales The Plessey Co Ltd (Components Group) Dubilier Condenser Co (1925) Ltd Roberts Electronics Ltd Electrautom Ltd Salford Electrical Instruments Ltd Electroustic Ltd Southern Transformer Products Ltd Electrosil Ltd Walmore Electronics Ltd Erie Electronics Ltd Whiteley Electrical Radio Co Ltd G E Electronics Ltd Zenith Electric Co Ltd Holsworthy Electronics Ltd ITT Components Group Europe ITT Components Group Europe (Potentiometer Relays Division) Allen West (Brighton) Ltd lmpectron Ltd Alma Components Ltd Lindair Optronics (Industrial) Ltd Arrow Electric Switches Ltd Litton Precision Products Associated Automation Ltd May Precision Components Ltd Astralux Dynamics Ltd Morganite Resistors Ltd B & R Relays Ltd Mullard Ltd Brookhurst lgranic Ltd Pedoka Ltd Clare (C P) Electronics Ltd Penny & Giles Ltd Clifford & Snell Ltd The Plessey Co Ltd (Components Group) Cox Engineering Company Ltd Power Development Ltd Jack Davis (Relays) Ltd Radiospares Diamond H Controls Ltd Reliance Controls Ltd Engel & Gibbs Ltd Salford Electrical Instruments Ltd ERG Industrial Corporation Ltd Sprague Electric (UK) Ltd F R Electronics Walmore Electronics Ltd (A Division of Flight Refuelling) Waycom Ltd Hendrey Relays Ltd Welwyn Electric Ltd lmpex Electrical Ltd ITT Components Group Europe Keyswitch Relays Ltd Coils & Transformers Londex Ltd Abrex Electronics Ltd Macro- Marketing Ltd Aladdin Components Magnetic Devices Ltd Amphenol Ltd The Marconi Co Ltd Astralux Dynamics Ltd G A Stanley Palmer Ltd Ataka & Co (UK) Ltd Parmeko Ltd Avel Products Ltd Pedoka Ltd Bede Transformer Co Ltd Oliver Pell Control Ltd A F Bulgin & Co Ltd The Plessey Co Ltd (Components Group) Cambion Electronic Products Ltd Simmonds & Robinson Ltd Clarke & Smith Manufacturing Co Ltd Square D Ltd Drake Transformers Ltd Techna (Sales) Ltd Dynamo & Electrical Services Ltd Telerelay (Sales) Ltd 162 Thorn Bendix Ltd Duval (Electrical Components Division) Emihus Microcomponents Ltd The Valiant Engineering Co Fairchild Semiconductor Ltd Walmore Electronics Ltd Farnell Electronic Components Ltd Westinghouse Brake & Signal Co Ltd Ferranti Ltd Hird-Brown Ltd ITT Components Group Europe Printed Circuit Boards (Valve Product Division) ABC Electronics (Oldham) Ltd Jermyn Industries A B Electronic Components Ltd Lindair Optronics {Industrial) Ltd Bribond Printed Circuits Ltd Macro-Marketing Ltd Circaprint Ltd Marconi-EIIiott Microelectronics Ltd Cressall Printed Circuits Ltd Mullard Ltd Davall (S) & Sons Ltd The Plessey Co Ltd (Components Group) Exacta Circuits Ltd RCA Ltd (Electric Components Division) K & N Electronics Ltd SDS (Portsmouth) Ltd Litton Precision Products SGS (United Kingdom) Ltd M B Metals Ltd STC Semiconductors Ltd MEL Equipment Co Ltd Texas Instruments Ltd Mills & Rockleys (Electronics) Ltd Walmore Electronics Ltd Mullard Ltd Westinghouse Brake & Signal Co Ltd Technograph & Telegraph Ltd

Thermionic Valves & Tubes Connectors Aero Electronics Ltd A B Electronic Components Ltd Ataka & Co (UK) Ltd AMP of Great Britain Ltd Britimpex Ltd Amphenol Ltd Chelmer Valve Co Aviation Electrical & Radio Ltd Claude Lyons Belling & Lee Ltd Cole Electronics Ltd British Insulated Callender's Cables Ltd Dale Electronics Ltd DTV Group Ltd EMI-Varian Ltd Dale Electronics Ltd English Electric Valve Co Ltd Duval Ferranti Ltd Electrautom Ltd Hivac Ltd Emihus Microcomponents Ltd ITT Components Group Europe Farnell Electronic Components Ltd Litton Precision Products Ferranti Ltd The M-0 Valve Co Ltd Greenpar Engineering Ltd Mullard Ltd Guest International Ltd Rank Electronic Tubes ITT Electronic Services RCA Ltd (Electric Components Division) Intel Connectors Ltd Siemens (United Kingdom) Ltd Klippon Electricals Ltd Thorn Radio Valves & Tubes Ltd Lemosa Ltd Twentieth Century Electronics Ltd MB Metals Ltd Walmore Electronics Ltd Macro-Marketing Ltd Metway Electrical Industries Ltd The Plessey Co Ltd (Components Group) Semiconductors Racal Electronics Ltd Aero Electronics Ltd Radiall Microwave Components Ltd Britimpex Ltd SDS (Portsmouth) Ltd Cole Electronics Ltd Townsend-Coates Ltd Dale Electronics Ltd Walmore Electronics Ltd

163 Addresses ABC Electronics (Oldham) Ltd Arrow Electrical Switches Ltd Bosch Ltd 83 Lees Road Brent Road PO Box 166 Oldham Southall Rhodes Way Lancashire Middlesex Watford WD2 4LB 061 624 8812 01-574 2442 Herts Watford 44233 A B Electronic Components Ltd Associated Automation Ltd Abercynon Dudden Hill Lane Bribond Printed Circuits Ltd Glamorganshire London NW10 Terminus Road Abereynon (044374) 331 01-459 8070 Chichester Sussex Abrex Electronics Ltd Astralux Dynamics Ltd Chichester (0243) 84516 6 Winchelsea Road Brightlingsea Forest Gate Colchester London E7 Essex Britimpex Ltd 01-534 2409 Brightlingsea (020630) 2517/8 8-12 Rickett Street London SW6 Advance Filmcap Ltd Ataka & Co (UK) Ltd 01-385 0883 & 1007 Rhosymedre Roman House Wrexham Wood Street Denbighshire London EC2 British Insulated Callender's Cables Ltd North Wales 01-638 8901 PO Box No 5 Ruabon (097 881) 2471 21 Bloomsbury Street Avel Products Ltd London WC1 Aero Electronics Ltd 13-16 Ayron Road 01-636 1600 Gatwick House Soud1 Ockendon Horley Essex Brookhirst lgranic Ltd Surrey South Ockendon (700) 2263 Elstow Road Horley (029 34) 5353 Bedford Aviation Electrical & Radio Ltd Beds. Aladdin Components Moons Lane Bedford (0234) 67433 Greenford Horsham Middlesex Sussex A F Bulgin & Co Ltd 01 578 2300 Horsham (0403) 60206 By-Pass Road Barking Allen West (Brighton) Ltd B & K Instruments Ltd Essex Moulsecoombe Way 59 Union Street 01 -594 5588 Brighton BN2 4QE London SE1 Sussex 01-407 4567 Cambion Electronic Products Ltd Brighton (0273) 66666 B & R Relays Ltd Cambion Works Castleton Alma Components Ltd Temple Fields Harlow Nr Sheffield S30 2WR Diss Hope (Derbyshire) (043 32) 406 Norfolk Essex Diss (0379) 2287 Harlow (027 96) 25231 CGS Resistance Co Ltd Bede Transformer Co Ltd Marsh Lane AMP of Great Britain Ltd Bedesway Terminal House Gosport Street Bede Trading Estate Lymington Stanmore Jarrow Middlesex Hampshire Co Durham Lymington (059 07) 3282 01-954 2356 Jarrow (0632) 897281

Amphenol Ltd Belling & Lee Ltd Chelmar Valve Co Thanet Way Great Cambridge Road 130 New London Road Whitstable Enfield Chelmsford Kent Middlesex Essex Whitstable (022 72) 4345 01-363 5393 Chelmsford (0245) 55296

164 Circaprint Ltd Diamond H Controls Ltd Electrosil Ltd 17-21 Foster Street Vulcan Road North PO Box 37 Maidstone Norwich NOR 85N Pallion Trading Estate Kent Norfolk Sunderland Maidstone 55484 Norwich (0603) 45291 Co Durham Sunderland (0783) 71481 C P Clare Electronics Ltd Jack Davies (Relays) Ltd Stonefield Way 9-10 Mallow StreP.t Electro-Voice Products South Ruislip Old Street Maple Cross Industrial Estate Middlesex London EC1 Rickmansworth 01-845 1288 01-253 3661 Herts Rickmansworth (79) 75381 Clarke & Smith Manufacturing Co Ltd Drake Transformers Ltd Emihus Microcomponents Ltd Melbourne Works Kennel Lane Heathrow House Melbourne Road Billericay Bath Road Wallington Essex Surrey Billericay (027 74) 51155 Hounslow 01-669 4411 Middlesex 01-759 9584/5 & 9961/2 Clifford & Snell Ltd DTV Group Ltd Hamilton Road 32 Carshalton Road 126 EMI-Varian Ltd West Norwood Sutton Hayes SE 27 Surrey London Middlesex 6166 01-642 2255 01-670 01-573 3888

Cole Electronics Ltd Dubilier Condenser Co (1925) Ltd Engel & Gibbs Ltd Lansdowne Road Ducon Works Elstree Way Croydon CR9 2HB Victoria Road Borehamwood Surrey North Acton Hertford shire 01-686 7581 London W3 01-953 2291 01-992 8671 Colvern Ltd English Electric Valve Co Ltd Spring Gardens Duval Chelmsford Romford 44 George Street Essex Essex Oxford Chelmsford (0245) 61777 Romford 62222 Oxford (0865) 48549 ERG Industrial Corporation Ltd Cox Engineering Co Ltd Luton Road 14 Park Lane Dynamo & Electrical Services Ltd Dunstable S10 Sheffield Unity Works Bedfordshire Sheffield 62482 Pearson Street Dunstable 62241 Blackburn BBR 2ER Cressall Printed Circuits Ltd Lancashire Erie Electronics Ltd Reddicap Trading Estate Blackburn (0254) 53611 South Denes Sutton Goldfield Great Yarmouth Warwickshire Norfolk 021-354 8048 Elden Electronics Ltd Transformer House Great Yarmouth (0493) 4911 Dale Electronics Ltd 370--372 York Road Exacta Circuits Ltd 1 09 Jp,rmyn Street Wandsworth Abbots Factory London SW1 London SW18 Galashiels 01-930 0725 01-874 4131/2 Scotland Galashiels (0896) 3396 Daly (Condensers) Ltd Electrautom Ltd Granby Works Components Division F R Electronics Granby Industrial Estate 34 High Street Wimborne Weymouth Tonbridge Dorset Dorset Kent Wimborne (020 124) 2442 Weymouth 2871 Tonbridge (073 22) 61234

S Davall & Sons Ltd Fairchild Semiconductor Ltd Wadsworth Road Electroustic Ltd Kingmaker House Perivale 73b North Street Station Road Greenford Guildford New Barnet Middlesex Surrey Hertfordshire 01-998 1011 Guildford 65333 01-440 7311 165 Farnell Electronic Components Ltd Hird-Brown Ltd ITT Electronic Services Canal Road Lever Street Edinburgh Way Leeds LS12 2TU Bolton Harlow Yorkshire Lancashire Essex Leeds (0532) 636311 Bolton (0204) 27311 Harlow (027 96) 26777

Ferranti Ltd Hivac Ltd lmpectron Ltd Hoi linwood Stonefield Way 23-31 King Street Lancashire South Ruislip London W3 061-681 2000 Middlesex 01-992 5388 01 -845 1288 Foster Transformers Ltd Morden Road lmpex Electrical Ltd Holsworthy Electronics Ltd London SW19 Market Road Holsworthy 01-542 2211 Richmond Devon Surrey Holsworthy 572 Gardners Transformers Ltd 01-876 1047 Somerford Road Christchurch Howells Radio Ltd Intel Connectors Ltd Hants BH23 3PN Carlton Street Vereker House Christchurch 2284 ManchP.ster 14 1-6 Gresse Street Lancashire London W1 P 1 DF GE Electronics (London) Ltd 061 -226 3411 01 -637 1151 Earply HousB 182/184 Campden Hill Road A H Hunt (Capacitors) Ltd Jermyn Industries Kensington Vulcan Way Vestry Estate London W8 New Addington Sevenoaks 01 -727 0711/3 & 5008 Croydon CR9 OBH Kent Surrey Sevenoaks (0732) 51174 Greenpar Engineering Ltd Lodge Hill (503) 2661 Station Works K & N Electronics Ltd Harlow Cordwallis Street Essex IRC Components Ltd Maidenhead Harlow (027 96) 27192 Tredegar Monmouthshire Berkshire Maidenhead 22447 Gresham Transformers Ltd Tredegar 2106 Twickenham Road Hanworth ITI Components Group (Capacitor Keyswitch Relays Ltd Middlesex Division) 1 20-132 Cricklewood Lane 01-894 5511 Brixham Road London NW2 Paington 01-452 3344 Guest International Ltd Devon Nicholas House Paington (0803) 50762 Klippon Electricals Ltd Brigstock Road Power Station Road Thornton Heath Sheerness ITT Components Group EuropB Surrey CR4 7JA Kent (Rectifier Products Division) 01-684 9731 Edinburgh Way Sheerness (079 56) 3093 Harlow Hawnt & Co Ltd Essex Lambda Electronics 11 2-114 Pritchett Street Harlow (027 96) 26811 21 Aston Road Birmingham 6 Waterlooville Warwickshire Hants ITT Components Group Europe 021-359 4301 Waterlooville (070 14) 51577 (Potentiometer Division) Hendry Relays Ltd Broad Lane Leeds 13 390-394 Bath Road Lemosa Ltd Slough Yorkshire PO Box 306 Bucking hamshire Pudsey (097 35) 77261 Shoreham By Sea Burnham 4611 Sussex ITT Components Group Europe Shoreham (079 17) 5262 Hinchley Engineering Co Ltd (Valve Product Division) Pans Lane Brixham Road Lindair Optronics (Industrial) Ltd Devizes Paington 6/12 Tudor Place Wiltshire Devon London W1 Devizes 3573 Paington (0803) 50762 01-637 1601

166 Litton Precision Products Ltd Metway Electrical Industries Ltd Penny & Giles Ltd 95 High Street Metway Works Mudeford Slough Canning Street Christchurch Buckinghamshire Brighton Hampshire Slough 28267 Sussex BN2 2ES Highcliffe (042 52) 2233 Brighton (0273) 66433 Londex Ltd The Plessey Co Ltd PO Box 79 Mills & Rockleys (Electronics) Ltd Components Group 207 Anerley Road Garnett Place Kembrey Street London SE 20 Gillebrands Industrial Estate Swindon 01-778 3111 Skelmersdale Wiltshire Lancashire Swindon (0793) 6211 London Electrical Manufacturing Co Ltd Tawd Vale 3346 Beavor Lane Hammersmith Power Development Ltd Morganite Resistors Ltd London W6 Cadmore Lane Bede Industrial Estate 01-748 2424 Cheshunt Jarrow Hertfordshire Co Durham Claude Lyons Waltham Cross 26896 Jarrow 897771 Tubes Departmt:mt 76 Old Hall Street Racal Electronics Ltd The M-0 Valve Co Ltd Liverpool L3 9PX Western Road Brook Green Works 051 -227 1761 Bracknell Hammersmith Berkshire London W6 Macro- Marketing Ltd Brackn

Salford Electrical Instruments Ltd Techna (Sales) Ltd Peel Works Parkville House The Valiant Engineering Co Ltd Barton Lane Bridge Street 248--250 Lavender Hill Eccles Pinner London SW11 Manchester M30 OHL Middlesex 01-228 3388 Lancashire 01-868 8802 061-789 5081 Vitramon Europe Technograph & Telegraph Ltd Wycombe Lane SDS (Portsmouth) Ltd Fleet Wooburn Green Hilsea Industrial Estate Aldershot High Wycombe Portsmouth P03 5JW Hants Bucks Hampshire Fleet (02514) 3414 Bourne End 22661 Portsmouth (0705) 62332/3 & 62180 Telephone Manufacturing Co Ltd SGS (United Kingdom) Ltd Capacitor Division Walmore Electronics Ltd Planar House Old Meadow Road 11-1 5 Betterton Street Walton Street Hardwicke Trading Estate Drury Lane Aylesbury Kings Lynn London WC2 Buckinghamshire Norfolk 01 -836 0201 /5 Aylesbury (0296) 5977 Kings Lynn 3855 Waycom Ltd Siemens (United Kingdom) Ltd Telerelay (Sales) Ltd Wokingham Road Great West House No 1 Factory Bracknell Great West Road Park Drive Industrial Estate Berks RG 12 1 N D Brentford Braintree Bracknell (0344) 24571 Middlesex Essex 01-568 9133 Braintree 2801/3 Wego Condenser Co Ltd Simmonds & Robinson Ltd Bideford Avenue Texas Instruments Ltd Perivale 44 Park Street Manton Lane Camberley Greenford Bedford Middlesex Surrey Bedford (0234) 67466 Camberley (0276) 25501 01-997 4277

Southern Transformer Products Ltd Thorn Bendix Ltd Welwyn Electric Ltd 301 Richmond Road (Electrical Components Division) Bedlington Twickenham Great Cambridge Street Northumberland Enfield Middlesex Bedlington (067 082) 2181/9 01 -892 9141 /2/3 Middlesex 01-363 5353 Sprague Electric (UK) Ltd Westinghouse Brake & Signal Co Ltd 82 York Way Sprague House Thorn Radio Valves & Tubes Ltd Kings Cross 159 High Street Brimar Sales Dept London N1 Views ley 7 Soho Square 01-837 6432 West Drayton London W 1 01 -437 2444 Middlesex West Drayton 4627 Townsend Coates Ltd Whiteley Electrical Radio Co Ltd Victoria Street Square D Ltd Coleman Road Leicester Mansfield Cheney Manor Nottinghamshire Swindon Leicester (0533) 68561 Mansfield (0623) 24762/5 Wiltshire Swindon (0793) 6222 Twentieth Century Electronics Ltd Centronic Works Zenith Electric Co Ltd STC Semiconductors Ltd King Henry's Drive Pinecrest Works Footscray New Addington Cranfield Road Sidcup Croydon CR9 OBG Wavendon Kent Surrey Bedfordshire 01-300 3333 Lodge Hill (503) 2121 /6 Woburn Sands 2531 /7 168 Glossary of Terms

Absolute maximum system: a system project and relates to components Capacitor: (electrical) basically two of electrical and thermal ratings for and materials which are acceptable conductors separated by an insulat• components under which the figure to both parties. ing layer; a component possessing given for a particular parameter Aquadag: a trade name for a appreciable capacitance, often a cannot be exceeded without the graphitised carbon conductive coat• multilayer unit; formerly termed a risk of permanent damage to the ing applied to the inner surface of condenser. component. cathode ray tubes and some other Carbide cermets: cermets based Accelerated test: a test applied to thermionic valves. mostly on titanium carbide with components in which the level of Armature type relays: a term used to nickel, cobalt, or iron based alloys applied stress exceeds that stated in cover the broad spectrum of electro• for the metal. the reference conditions in order to magnetic relays which have an Carbon composition resistors: resistors shorten the time required to observe armature hinged or pivoted to the in which the resistive element con• the stress response of the item. fixed yoke of the relay; operating sists of finely divided carbon, an Acoustic surface wave devices: single from either a.c. or d.c. inert filler and a synthetic resin crystal semiconductor devices in Assessed: electronics reliability; a binder pressed into the form of a which amplification is achieved by statistical adjective meaning that rod and cured; the ends may be passing a signal along the surface result determined as a limiting value sprayed with metal and have of a semiconductor chip as a of the confidence interval with a soldered leads or a metal end cap, mechanical wave which interacts stated probability level based, alternatively leads may be embedded with the electrical properties of the usually, on the same data as the in the rod before pressing. crystal, giving an increase of the observed result on nominally Catastrophic failure: a classification of power transfer. identical items. failure in electronics devices which AHoy diode: a diode manufactured atta: prefiix used in metric units giving covers both suddenness and degree; from a semiconductor wafer to a value of lQ-18; symbol a. a catastrophic failure is both which contact leads are welded. Base: semiconductors; the region sudden and complete. Amplification factor: (elec) thermionic between the emitter and collector in CDL: (elec) core diode logic. valves; the ratio of the change in a junction transistor. Clark ceO: a standard cell used in anode voltage to the change in Betatron: a circular electron accelera• high accuracy measuring bridges control grid voltage producing that tor employing magnetic induction etc where current requirements are effect. as the accelerating medium. minimal; mercury-zinc construction. Amplitude modulation: (elec) impart• Bifilar winding: a method of pro• Coil constant: the ratio of an ing intelligence to a radio carrier ducing non - inductive wound inductive coil's reactance to its wave by causing the amplitude of electronic components by winding effective resistance at a given the wave to vary in sympathy with half the turns back over themselves. frequency. the amplitude of the modulating Bound joints: an electrical connection Coil loading: (elec) improving the per• waveform. method in which the lead wire is formance of a transmitting line by Analogue computing: an electronic laid parallel to the length of the the insertion of inductive coils at computing system in which the terminal adjacent to the wide face predetermined intervals. quantities to be computed are and secured by several turns of Commercial relays: electrical relays represented by the magnitude of wrapping wire. designed to perform reliably under generated voltages. Burn-in: the operating of electronic conditions likely to be met in APL: The abbreviation generally components for a period of some normal applications. recognised for Approved Parts and hours prior to their integration in Complete failure: a classification as Materials List; this list is the result a circuit under varying temperature to the degree of failure of an of discussions between purchaser conditions which simulate their electronics device, used to cover and manufacturer on a particular eventual operational environment. failures resulting from deviations in 169 the characteristics beyond specified CW transmission: continuous wave of an item, beginning at some limits such as to cause a complete transmission; information trans• stated time and during which the lack of the required function. mission by means of transmitted failure rate of some items is Conductivity: (thermal) transfer of radio waves which do not vary in decreasing rapidly. heat through a medium without either frequency or amplitude. ECL: (elec) emitter coupled logic. apparent movement, by inter• Damped oscillation: a oscillatory Electroluminescence: a property pos• molecular energy effects (heat units I function of successively decreasing sessed by certain solids which unit area and time, eg J fm2s or cycle amplitude. causes them to emit light when W/m2); DCL: (elect) direct coupled logic. placed in a varying electric field. (electrical) passage of current Degradated failure: a classification of Electron gun: collective term for the through a medium by movement of failure in an electronics device emitter and grids of a cathode ray charge carriers (eg electrons and/ or which covers both suddenness and tube responsible for the generation, ions) under the influence of a degree; a degradation failure is acceleration and initial focusing of potential gradient; reciprocal of both gradual and partial. the electron beam. volume resistivity; unit of con• Delay line: (electronics) a transmission Electro-optical tubes: a term generally ductance, mho; of restivity, ohm. line of such characteristics as to recognised as covering cathode ray Conformal coatings: coatings using retard the time of arrival of a tubes, camera tubes, storage tubes plastics varnishes with the addition transmitted signal. and image intensifiers. of plasticisers which are sufficiently Demodulation: the process of extract• Encapsulation: sealing (potting) of an flexible to allow the coated com• ing intelligence from a transmitted item or structure within, typically, ponent to move slightly or expand radio wave; also detection. a plastics material for protection without damage. Derating: the process of operating a from environment; widely used to Constant failure rate period: a term component or system at parameters contain electronics components. used in electronics reliability con• lower than the maximum per• Extrapolated: electronics reliability; a cepts which refers to that period in missible levels, usually to offset the statistical adjective relating to an the life of an item during which effect of unusual or extreme con• extension of the observed or the failures occur to some items at ditions. assessed results with durations of an approximately uniform rate. DiJferential capacitor: a two-part stress conditions different from Contact: (electrical) device to com• variable capacitor designed so that those applying to the conditions of plete part of a current-carrying tuning the rotor increases the the assessed state. circuit; types include static capacitance of one section while Failure: electronics; the termination (stationary in normal use), sliding decreasing the other. of the ability of an item to perform (eg brush contacts on rotating DIP: dual in line package. its required function. machines, wiper or slide wires or Double-throw switch: a mechanical Failure rate: electronics; a term rails, pantographic collectors), open• switch where connection may be qualified by a statistical adjective, ing (switching devices). made by switching the blade into ie observed, assessed, extrapolated Continuous rating: a rating specifying either of two sets of contacts. and predicted; the proportion of electrical loads which can be Drift: (electronics) the change, usually failures in a particular period of handled by a device for indefinitely associated with time, of any para• time under stated conditions. long periods. meter of a component or Feedthrough capacitors: capacitors Cracked carbon resistors: cracked or characteristic of a circuit. used to decouple and illter RF pyrolytic carbon film resistors con• Dry reed relays: a coil acting on one circuits. sisting of ceramic rods over which or more magnetic reed switches femto: prefix used in metric units a hydrocarbon vapour has been which themselves consist of two units giVmg a value of lQ-15; passed and decomposed depositing ferromagnetic metal reeds, sealed symbol f. a thin carbon film; resistance value into a glass capsule and aligned to Ferrimagnetic (feiTomagnetic): pro~ is adjusted by cutting a heliw give a slight overlap at the contact perty of a material that has a groove through the carbon film and area. relatively high permeability which partially through the ceramic. Dry units: electronics-wound com• varies with flux density; notably Cryogenics: study of phenomena at ponents; coils and transformers to iron and ferrous alloys, compounds very low temperatures. which no further treatment is such as ferrites. Crystal can relays: hermetically sealed applied after assembly. Ferrite: (electronics) ferrimagnetic relays with balanced armatures and DTL: (elec) diode transistor logic. oxide material which exhibits a housed in enclosures originally Dual-in-line package (DIP): a combination of insulating and designed for the quartz crystal of packaged integrated circuit so called magnetic properties useful in oscillators. because it has two rows of in-line electronics applications; often a Crystal controUed osciUator: an pins; the pins are commonly 2.5 complex oxide of eg rare-earth electronic oscillator whose fre• mm apart and semi-rigid to allow metals and iron. (Metallurgy) a quency is locked to the natural the device to be easily inserted into metallic solid solution based on frequency of vibration of a piezo· PCBs and flow soldered; available alpha-iron. electric crystal. with 16 and 24 leads. FET: (elec) field effect transistor. Cryotron: (electrical) a logic element Duplex radio transmission: the Flashed filaments: electronics con• consisting of two thin strips of simultaneous transmission of two struction; carbon illaments which superconducting material in close intelligence-bearing radio waves on have been subjected to a flashing proximity; a relay or miniature one carrier wave. process in a carbon-containing electronic swich. Dynode: an electrode in a thermionic atmosphere to improve the CfL: (elec) core transistor logic. valve or similar device whose uniformity of their cross-section. Current gain: ratio of current in the function is secondary emission. Flat pack: (elec) a packaged integrated collector circuit to the current in the Early failure period: a term used in circuit, commonly with 14 leads emitter circuit of a transistor; electronics reliability concepts which available and measuring approxi• symbol a: refers to the early period in the life mately 6 mm x 6 mm.

170 Flux jump: (electrical) collapse of for converting d.c. to a.c. sisting of one or more mercury current path in a superconductor Ion: electrically charged particle (of switches, tilted by the movement of which has been driven into the atomic or molecular size) which can the relay armature. normal state by heat generated transport electricity by its mobility Mercury wetted reed relays: a form from movement of current path, through a fluid medium, eg of reed switch having a pool of eg near limiting current density of electrolyte or gas. mercury at its base which by a material. kilo: prefix used in metric units giving capillary action wets the contact Fragility factor: an electronic equip• a value of 103; symbol k. faces. ment rating relating to its handling Klystron: electronic valve for generat• Metal film resistors: resistors formed in mechanical transit; it is deter• ing or amplifying microwave by the deposition of a thin metal mined by a programme of drop quantities. film on a cylindrical ceramic tests to determine the deceleration Lambertian surface: electro-optics; a substrate and the cutting of a level which will cause damage to perfectly diffuse surface which has helical groove between the ends; the packaged equipment. a constant radiance independent of the film is usually lacquered and Frequency modulation: imparting the viewing direction. . the whole encapsulated for pro• intelligence to a radio carrier wave Laser: Light Amplification using tection. by causing the frequency of the Stimulated Emission Radiation; a Metal glaze (cermet) resistors: resistors wave to vary in sympathy with the device which produces a coherent formed by depositing a coating of amplitude of the modulating wave• beam of light which is very intense micrometric-sized glass and metal form. and almost parallel; various types particles dispersed in a viscous Full wave rectifier: an electronic of laser are gas, crystal and organic substance onto a ceramic circuit which converts each half injection. substrate and firing; the organic cycle of alternating current into Latching relays: relays designed to substances bum-off and the glass direct current. hold the contacts in the energised fuses and bonds to the substrate. Function generators: generators which position after the power has been Metal oxide film resistors: the film is deliver an electronic output signal removed from the energising coil. formed by the hydrolysis of an which is a function of the input Lateral p-n-p: electronics semi• aqueous solution of stannic voltage, ie sine, square, logarithmic. conductor device; generally a chloride on a glass, ceramic or Fuse: (general) melt; (electrical) device specially designed low beta glazed ceramic rod at red heat; used to protect equipment from transistor used in a linear circuit. resistivity and TCR is modified by overload; a conductor that fuses (ie Lidar: term for light detection and the addition of a small proportion breaks circuit) at specified load; ranging using lasers; operating ·on of antimony or boron compounds. energy of fusion is proportional to the same basic principles as radar. micro: prefix used in metric units the square of the cross sectional Light emitting diode: a low power giving a value of l0-6; symbol P.· area of the conductor. light source in the form of a semi· Microwave switching tubes: cold Garnet: (mineral) groups of materials conductor p-n junction diode; cathode gas filled tubes used for (including semi-precious gemstones) subject to continuing development. switching duties in radar applica• of cubic crystal structure; term lSI: generally recognised abbreviation tions. also used to describe crystallo• for large scale-integration; used in Microwave tubes: a term generally graphic class of materials, eg the electronics industry to cover recognised as encompassing families ferrites. multifunction integrated circuits. of tubes (valves) working in the giga: prefix used in metric units giving Luminous emittance: electro-optics; UHF bands; covers triodes, a value of 109; symbol G. the luminous flux output per unit travelling wave tubes, magnetrons, Gradual fallure: a classification of surface area. modulators, klystrons and micro• failure in electronics which applies Magnetron: a complex electronic wave switching tubes. when the failure could be valve capable of producing high Military relays: (elec) a general term anticipated by prior examination. output powers at microwave covering relays designed to operate IGFET: (elec) insulated gate field frequencies. under extremes of environmental effect transistor. MAS: metal alumina semiconductor. conditions. lgnitron: (electronics) mercury-arc Mass resistivity: (electrical) for a Misuse fallures: a classification of valve using a pool of mercury as material at a given temperature, the failure in which the failure is the cathode and capable of rectify• product of the density and volume attributable to the application of ing large currents. resistivity. stresses beyond the stated Impulse relays: usually a single coil Mean life: electronics; defined as the capabilities of the item. device; the armature alternatively mean value of the lengths of Mixed dielectric capacitors: capacitors transfers the contact system from observed times to failure of all whose dielectric is a combination of one state to another by means of a specimens in a sample of items plastic films and paper. mechanism holding the armature in under stated stress conditions; Moire fringe: the bands of light and one of two states. MTIF and mean life apply only shade which appear when a beam Inherent weakness fallures: a classifi• to non-repaired items, mainly com• of light passes through regularly cation of failure in electronics in ponents. spaced grids having the same pitch; which the failure is attributable to Mechanical interlocking relays: used in transducers for linear a weakness inherent in the item essentially two-coil three-position measuring techniques. itself when subjected to stresses devices, usually consisting of two MOS: (elec) generally recognised within the stated capabilities of the relays on a common base with a abbreviation for metal oxide silicon item. mechanical link preventing the semiconductor 'devices. Inrush loads: instantaneous currents operation of one relay whilst the MTBF: mean time between failures experienced on the closing of relay otb.er is energised. (electronics etc); a term which contacts, many times greater than mega: prefix used in metric units refers to repairable items and the steady-state value of the load. giving a value of 106; symbol M. defined as: for a stated period in Inverter: electronic circuit or device Mercury switch relays: relays con- the life of an item, the mean value 171 of the lengths of observed times characteristics of an equipment Shrunken raster: a method of measur• between consecutive failures under based on the observed, assessed or ing line width (electronic display stated stress conditions. extrapolated reliability (or failure devices) in which a raster having MITF: mean time to failure rate) of HS parts, and taking into a known number of lines is reduced (electronics etc); defined as: for a account the circuit design. in ampitude until the lines appear stated period and under stated Pulse width modulation: a method of to merge; the width is then taken as stress conditions the total transmitting intelligence employing being the raster height divided by cumulative observed time divided electrical pulses of equal amplitude the number of lines. by the total number of failures in but of varying time duration. SIC: (elec) silicon integrated circuit. the population during the period. 'Q' factor: the measure of the 'good• Side contact connector: a type of oano: prefix used in metric units ness' factor of a component; for connector used in association with giving a value of lQ-9; symbol n. an inductive coil the ratio of the PCBs containing a number of Observed: electronics reliability; a reactance to the total resistance at spring fingers which made contact statistical adjective meaning that that frequency. with pads on the board result which is obtained by RCI'L: (elec) resistor - capacitor Solenoid actuated relays: alternatively observing the number of actions transistor logic. called relay contactors, these which occur in a certain time to a Reftow soldering: a method of making operate on the principle of a soft single item or a number of items. electrical connections whereby com• iron core being attracted to a pole Operatiooal amplifiers: directly ponents whose leads have been face situated in the centre of the coupled electronic amplifiers of previously tinned may be assembled coil, the coil normally being sur• infinitely high gain capable of and connection made by reflowing rounded by a magnetic m

172 TFFI': (elec) thin film field effect Travelling-wave tube: electronic valve vacuum; the two basic processes are transistor. in which microwave signals are vacuum evaporation and cathodic Thermoelectric cycle: the phenomena amplified by interacting with an sputtering. resulting from the flow of direct electron beam. Video amplifier: wide band electronic current through a junction of dis• TRL: (elec) transistor-resistor logic. amplifier capable of handling video similar metals; one junction is TTL: (elec) transistor-transistor logic. frequency signals. cooled, the other heated. Type-tests: tests carried out by the Waveguides: hollow metal tube-like Thermoelectric generation: the electronic component manufacturer structures used for transmitting practical application of the electro• intended to prove the design of a electrical energy in the frequency motive force produced when a particular component for its range 1000 to 200 000 MHz. junction between dissimilar con• application. Wear-out failure period: a term used ductors is heated. Ultrasonic soldering: a soldering in electronics reliability concepts Thick film resistors: formed by screen method utilising high frequency which refers to that period during printing an ink (consisting of finely vibration energy to provide local the life of items when the failure divided particles of a metal or metal heat, avoiding the formation of rate of some items is rapidly oxide, fine glass powder and a metal oxides. increasing due to deterioration binder dispersed in an organic Unipolar transistors: an insulated gate processes. liquid) onto a ceramic substrate and field effect transistor consisting of a Wrapped joints: a wrapped electrical subsequent drying and firing. thin layer of the semiconductor, joint is one in which a rectangular Transducer: a device used to convert cadmium sulphide, on an insulating pin or stake is tightly bound several the magnitude of one parameter substrate with metal contacts form• times with wire; a special tool is into the magnitude of another para• ing the source and drain terminals. used to make the wrap and this mater, usually more easily Vacuum deposition: the process of method breaks down any surface measured. growing thin solid films in a film on the pin or the wire.

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