FORMSWRTHYPHASCISPELPRGHDOC h PICP69LINP6Z BOXP6Z dOVLP6Z dSWCL@BlackWhiteRedGreenBlueCyanYellowMagentafSalmonwPeachUBrownellowLight GreenwwwGrey DarkOrangeݙVanillalowGrey LightIDXHIDXDSoftSansdTitleepz,IDXDSoftSansdBlank LinefIDXDSoftSansdLetter HeadergIDXDSoftSans dIndex EntryhTOCH TOCDSoftSansdTitlenz%TOCDSoftSans dBlank LineoTOCDSoftSansdZLevel 1pTOCDSoftSans dZLevel 2qTOCDSoftSerif dLevel 3rTOCDSoftSerif dhLevel 4sTOCDSoftSerif dvLevel 5tTOCDSoftSerif d*Level 6uTOCDSoftSerif dLevel 7vTOCDSoftSerif d8Level 8wIDXPSEC1 PTPAG3pA PRN3KBVtils:APPLICATIONS/FinalWriter/FWFonts/SWOLFonts/Serif/WŬWW~WW { dELX.FormulaText{WPASDSoftSansdDocument TitlePASDSoftSansdSection Namepz??PASDSoftSansdTopic Nameq{??PASDSoftSansdSub Topic 1r|??PASDSoftSansdSub Topic 2s}??PASDSoftSans dBodyPASDSoftSans dIndented BodyTOCP!rOUTPBIBPTOIPENDPDSP2PHHFDASoftSans dSoftSans dPNDASoftSans dSHPP6Z dGRMRStrictly.For Business Writing.For Casual Writing.Custom 1.Custom 2.Custom 3.IDXLConductorsTDINFFCOP3`WA2W*FDTASoftSans_BoldvxW.*W.*W.*WŬUtils:APPLICATIONS/FinalWriter/FWFonts/SWOLFonts/W2\TWPPW/VWtW%@W/Y~W/0VW/VFDTAWorchester Utils:APPLICATIONS/FinalWriter/FWFonts/SWOLFonts/Serif/FDTASoftSansW8W%YW$PWwLWW$oW$WtW_W$PW# W$WtW~GINF  GINFUtils:GRAPHICS/PPaint/Brushes/FWriter5/CellsSeries.bshN@N@ X9BlackFORM~ILBMBMHD0UV,CMAP @@CAMGBODY6`n)<n)?[o?D[o% D)% C% Dd)% [%D%% S$% f |f  8 8 |8 | 8 |10?c c8  8sx~9;~1#c1c8 8s89;;~1?c?c88 s89;;`~?1?>?cc80?8>'s898;;~ ?1??c1b"8?8 s898;;~~1?c1b"88 s8?9;;~ ~?1??c1b"8? sp898;;~ }1??1b"8?8  s@H8989;~ 3c1f"8?8  3@pf809~ 1"8?8  H<8x8~?? 8  @H80`߀~8 @p~888888{DŽ@=wc <"D@w"  "G@}w{# 8"@@߽w} B "@߾ A@PW G + 8>8qs88qs88qs 8p ~~ qs"#8"#8|DDqwwps;#8#8||Dqwwps8b""80c8||qϜwws" 8#8|q ww?"8"#8|DDqwwp;"8"#8|DDqwwp;b# 0`p~@ϟs88888?88?F?F?88psF?F?88qpp8s F?@ 88p p8sF?F""#88ppsF>F""#8pp~8?sF?F""#p8sF>F""#pp~8??`?F""#|p8$~?F""#pp8$?σ~? 1F"" 0|pp8=?~?? 0p$???$?? 0GINFUtils:GRAPHICS/PPaint/Brushes/FWriter5/CellsParallel.bshFP.FP.d%ln9BlackFORMILBMBMHDiw,CMAP @@CAMGBODYk    ` y 0 v H v H v x v HYH=c " }# ߽ B ߾ A@+      `88 s a ݭ "R ݭ "R ݡ "^ ݭ "Rm)1>!_ ??@?!0??99?9w8s8?1#?99s9w8s8?1?? 999w8s8?1>??` 99?9w8s8?!1???DGG9?9p?9w8s?1??DG 99p9w8s &??1???DG  "98?9p?9w8s>1??DG9 $9p9ss8`~qc?GG 8fs`83;[Ì?#GG!_ ?@0?1~#1c?9?1c?9>?1 c ??1c""#9???1 c""# 9?1c""# $9? c""#$9 # c""# =9 # c""#  $s9 ? ""$q9`???<[D[DCD[DS$=c " }# ߽ B ߾ A@+~<gfgfgggf<GINF 3JZ BlackMagentaGINF SHD1PW? W?dW?PTMainTBDYRULEWATTR dCHRSElectronic Servicing yr.1 pt.1ATTR dCHRS ATTR hdCHRS ATTR hdCHRS ATTR dCHRSLecture: 010.T ATTR [dCHRS ATTR hdCHRS ATTR hdCHRS ATTR hdCHRS ATTR hdCHRSTATTR hdCHRShu - 21 - NovemberATTR hdCHRS ATTR hdCHRS-1996RULEATTR dCHRSRULEATTR xCHRSCells (Batteries)RULEATTR dCHRSRULEATTR dCHRSA cell is a device that provides a source of electricity from a chemical reaction hence, converting chemical energy to electrical energy. Every cell has its Voltage that it supplies and its internal resistance.RULEATTR dCHRSRULEATTR1 dCHRS1The Voltage that the source produces is known as ATTR dCHRSElectro Motive Force (E.M.F.)ATTR dCHRS and is the voltage supplied when a source has no load. When a load is connected to the cell, the voltage given is now referred as ATTR dCHRSPATTR dCHRSoATTR dCHRStential Difference (p.d.).ATTRc dCHRSc The EMF is always slightly higher from the p.d. because every cell has in it what is known as the ATTR dCHRSInternal ResistanceATTR dCHRS, a hidden resistance which iATTR dCHRSsATTR dCHRS ATTR dCHRSaATTR- dCHRS-lways in series with the source in a circuit.RULEATTR dCHRSRULEATTR dCHRSElectricity can be supplied also by dynamos, apart from cells, in which they convert mechanical energy to electrical energy. There are differences between a chemical source of electricity and a mechanical source of electricity (dynamo). RULEATTR dCHRSRULE$BATTR# dCHRS#When a chemical cell is brand new, ATTRM dCHRSMthe Internal resistance is very small, and as this is in series with the cellATTR dCHRS, it does not alter very much the current output of the cell. As, by time, the cell is used, its Internal Resistance becomes larger and larger until the output current eventually is minute and becomes zero. The dynamo (or alternator) also has its internal resistance, but this is fixed and so will always keep the same initial value. As for the chemical source, the Internal resistance of dynamos is always in series with the source. RULEATTR dCHRSRULEATTR dCHRSIn a chemical cell, this Internal Resistance is made up of the chemicals making up the cell. In the dynamo or alternator the Internal Resistance is in the wire wound around the former (copper winding resistance) and this is permanent (do not change with time).RULEATTR dCHRSRULE ATTRdCHRSCells in SeriesRULEATTR dCHRSRULEATTR dCHRSRULEATTR dCHRSRULEATTR dCHRSRULEATTR dCHRSRULEATTR dCHRSRULEATTR dCHRSRULEATTR dCHRSRULEcATTRc dCHRScCells can be connected in series to provide a higher voltage since the total voltage between AB is RULEATTR dCHRSV1 + V2 + V3 + V4 = 1.5 + 1.5 + 1.5 + 1.5 = 6.0 Volts. When connected in series, the batteries can be of different voltages.RULEATTR dCHRSRULEATTR dCHRSThe current produced by the battery is the smallest current the smallest cell can provide. Hence if there are three powerful (torch) battries of 1Amp, and a pencil battery of 0.9Amp, the total current across the circuit is of 0.9Amp.RULEATTR dCHRSRULEBATTRO dCHRSOCells are connected with the same Voltage, size, current, (ampere hour capacity), and also of the same type and make. Also one must ensure that the polarity of the cells are connected as shown. The voltage of an inverted cell is subtractive! A battery consists of a collection of cells which maybe connected in series or in parallel. ATTR@ dCHRS@Cells are connected in series to provide a higher Voltage outputATTR dCHRS.RULEATTR dCHRSRULE ATTRdCHRSCells in parallelRULE ATTRdCHRSRULE ATTRdCHRSRULE ATTRdCHRSRULE ATTRdCHRSRULE ATTRdCHRSRULE ATTRdCHRSRULE ATTRdCHRSRULE ATTRdCHRSRULE4ATTR4 dCHRS4Cells connected in parallel must always be of the same voltage, and connected in such a way that their positive terminal of each cell is connected to the other positive terminals of the other cells. When cells are in parallel, the voltage between AB remains the same Vtot = V1 = V2 = V3 = V4 = 1.5Volts.RULEATTR dCHRSRULE,ATTR dCHRSHowever the total current is the sum of current that each cell supply and hence the overall current in the circuit is high. Itot = I1 + I2 + I3 + I4 = 4.0Amps. ATTR\ dCHRS\Cells are connected in parallel to provide a higher current capacity or ampere hour capacityRULEATTR dCHRSRULEATTR dCHRSExample:ATTR dCHRS ATTRY dCHRSYWhat is the total voltage and current of a battery having 3 identical cells connected in ATTR hdCHRS ATTR hdCHRS ATTR dCHRSparallel of 4V and 1Amp each. RULECATTR hdCHRS ATTR hdCHRS ATTR hdCHRSVATTR hdCHRStotATTR hdCHRS = V1 = V2 = V3 = 4VoltsATTR (dCHRS ATTR hdCHRS ATTR hdCHRSIATTR hdCHRStotATTR hdCHRS = I1 = I2 = I3 = 3AmpsRULEATTR dCHRSRULEATTR dCHRSRULE ATTRdCHRSAmpere Hour - AHRULEATTR dCHRSRULEJ,ATTR? dCHRS?The charge stored in a cell is equal to current x time ATTR  dCHRS Q = I T RULEATTR dCHRSRULE1ATTR1 dCHRS1The basic unit of charge is the Coulomb (C) and is equal to 1Amp x 1sec. The coulomb is a very small unit of charge for battries since their charge capacity is very large. So a bigger unit was introduced and this was called the AmpereHour (AH) which is equal to 1Amp for 1 hour, hence 1A x 3600s = 3600C.RULEATTR dCHRSRULEqATTRq dCHRSqSo a battery that stores 1 AH can be discharged by consuming 1A for 1 hour, or consuming 100Amps for 36 seconds. RULEATTR dCHRSRULEwATTRw dCHRSwFor smaller values of charge, the Milli, Micro and Nano Coulombs are used. Such small charges are used for capacitors. RULEATTR dCHRSRMSTRULEATTR dCHRSLMSTRULEATTR dCHRS