保险丝培训资料.ppt

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1、LittelfuseOCSelectionTrainingAnthonyChang2Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.WhoWeAre.Littelfuse Inc.成立於成立於1927年，為專業製造保險絲公司。自年，為專業製造保險絲公司。自1999至至2005年投入了過電壓保護元件製造而成為一家線路年投入了過電壓保護元件製造而成為一家線路保護元件的保護元件的CircuitProtectionProvider的跨國公司。的跨國公司。總總部設在美國伊利諾州部

2、設在美國伊利諾州DesPlaines市，擁有十幾家工廠分市，擁有十幾家工廠分佈在美、歐、亞三大洲七個國家，在世界各地設有區域性佈在美、歐、亞三大洲七個國家，在世界各地設有區域性營銷中心。營銷中心。3Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.1927 Firstinstrumentfuses1976 ATObladefuse1992 Surfacemount(D-Case)1994 SquareNanofuse1994 A-Case(1206)1996 0603su

3、rfacemount1997 PTCResettableDevice1999 ESDProtectors/HarrisSuppression2002LeadFree1206,0603&0402sizeFuse2002SemitronOverVoltageProducts(TVSDiodes&GDT)2003TECCOR(PowerThyristor&Sidactor)2004WickmannIntegration4Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.Fuse

4、selectionFusereviewBasicsoffuseApplicationofAspectsSelectingafuseFuse ratingI2t ratingExampleofin-rushcurrentDemonstrationoftriptimesDownsidesandsolutionsOverview:5Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.Fusefunctionality-LimitedcurrentvsPotentialcurren

5、tCircuit response without fuse protection current is eventually disrupted(in an unpredictable manner)due to the failure of a component or circuit board traceFused circuit -current is interrupted in a controlled manner(by the fuse)to avoid damage to circuit components -circuit is allowed to fail“grac

6、efully”I(A)tFuseA Fuse is a TemperatureSensitiveDevice that serves as an intentional Weak Link in an electrical circuit.It interrupts overload and short-circuit conditions when its metallic element melts;thereby halting the overcurrent condition.6Confidential and Proprietary to Littelfuse,Inc.2006 L

7、ittelfuse,Inc.All rights reserved.FuseReview:Construction Traditional Cartridge Type Vs.Slimline Thin Film TypeCAPCAPSOLDERSOLDERFILAMENTFILAMENTBODYBODYSOLDERSOLDERCAPCAPCartridge fuseThin Film fuseThe metallic element(filament)melts and disconnects the power to the circuit.7Confidential and Propri

8、etary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.SMDFuse1.-CeramicBody.2.-FuseendcapsTin-LeadandRoHS(SilverorGold)platedcaps.3.-Filament(AgAlloy)for451&CeramicYarnandTinplatewirefor452451series452series8Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights rese

9、rved.FuseSolutionsfor:ACmainsovercurrentprotectionTip/RingcircuitprotectionCartridgeandleadedfuseIndustrystandardformfactors(cartridge,axialleaded,radialleaded)DesignedtoIEC,UL,METIFast-acting,medium-acting,andslo-bloversionsavailableLow,enhancedandhigh-breakingcapacityversionsavailableKeyfeatureist

10、hewidearrayofformfactors,amperageratings,voltageratingsandbreakingcapacitiesthatareavailable9Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.Cartridge,leadedfusePowersupplyPoweradaptorTVSSLightingballastConsumerelectronicsDVD,television,set top boxHomeappliance

11、sWasher,dryer,refrigerator,air conditioner,humidifierTip/ring-PowerCross(2AG)Targetapplications:AC line protection for power supplies AC lineCommon/groundPowermodulePowerplugPowersystemUltraMOV,CIII,LAseriesradialleadedMOVCartridgeorleadedfuseFusePower supplyTip/ring circuitPower supply10Confidentia

12、l and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.FuseSolutionsfor:BatterypackandDCbusovercurrentprotectionSurfaceMountChipFuseSpace-efficientformfactors(0402,0603,1206)Amperageratingsfrom0.062Ato7.0ALowprofileforheight-sensitiveapplicationsConstructedonanepoxy-basedsubstra

13、tesimilartothecircuitboardonwhichitwillbeinstalled.Avoidstemperaturecoefficientofexpansion(TCE)mismatchthatcouldcausereliabilityproblemsinthefield.KeyfeatureofFR-4substrateishighermeltingi2tvaluethanceramicchipfuse,whichminimizesnuisancetrippingduringin-rushcurrentevents.Lowerresistancevaluesalsomin

14、imizepowerdissipation.11Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.Solutionsfor:ACmains/DCbusovercurrentprotectionTip/RingcircuitprotectionSurfaceMountFuseIncludesNano2,TeleLinkandUMFseriesRatedforACandDCcircuitsAmperageratingsfrom0.25Ato15.0AConstructedus

15、ingceramictubebodiestoincreasebreakingcapacityandworkingvoltageKeyfeaturesarehighermeltingi2tvaluethanchipfuse,whichminimizesnuisancetrippingduringin-rushcurrentevents;wire-in-airdesignminimizesthermalde-ratingfactorandextendsusabletemperaturerange.FuseNano2UMFfuseTeleLinkfuseNano2fuse12Confidential

16、 and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.ChipfusesBatterypackHarddiskdriveCellphoneDigitalcameraLCDmonitorinverter(smallpanels)MP3/PMPplayerBluetoothheadsetWire-in-AirSMDfusesMotherboards(servers,notebooks)LCDmonitorinverter(largepanels)Telecomequipment(TeleLink)Aut

17、omotiveElectronicsmodulesTelematics,climate control,navigation,body controllersTargetapplications:Protection of inverter circuit(LCD)DC inputCommon/groundInvertercircuitDCinputPowersystemMLV(MLAseries)Diode(SMAseries)ChipfuseNano2fuseProtection of DC bus(HDD)Data busVBUSSignal GroundHDDunitRibboncab

18、le/connectorMotherboard0402,0603MLVSMAJdiodeShield Ground0467Pb-free0434Pb/Sn0435Pb-freeD0DnInverterFuseInverter13Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.WhatisaFUSE?1.Afuseisathermallyrespondingdevice.2.Afuseisdesignedandmanufacturedtoprotectbybeingthe

19、intentionalweaklinkinanelectricalcircuit.PurposeofthefuseistopreventFIRE!Fusing UltimateSystem End14Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.基基本本保保險險絲絲學學 15Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.保保 險險 絲絲 基基

20、 本本 工工 作作 原原 理理:結構:金屬熔絲及兩端極金屬熔絲及兩端極功能:保險絲是串聯在電路中保險絲是串聯在電路中,當電路正常工作時當電路正常工作時,保險絲只相當予一根導保險絲只相當予一根導線能夠長時間穩定地使用線能夠長時間穩定地使用.只有只有當電路中發生較大的過載電流和或發生短路時保險絲才會熔斷開電流來保護電路的安全.原理:保險絲通電時因電流轉換的熱量會使熔絲的溫度上升保險絲通電時因電流轉換的熱量會使熔絲的溫度上升.當正常工作電流當正常工作電流或允許的過載電流通過時或允許的過載電流通過時,電流產生的熱量通過熔絲電流產生的熱量通過熔絲,殼體向周圍環境輻射殼體向周圍環境輻射,通通過對流和傳導等

21、方式散發的熱量能與產生的熱量逐漸達到平衡過對流和傳導等方式散發的熱量能與產生的熱量逐漸達到平衡.當散熱速跟不上發熱時這些熱量就會在熔絲上逐漸累積,使溫度上升,一旦溫度達到和超過熔絲材料的熔點時會使熔絲熔化而斷開電流,達到保護的作用.16Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.保險絲允許的過載能力保險絲允許的過載能力(FuseCurrentCapacity)Max.Carryingcurrent:ULSTD保險絲的保險絲的最大不熔斷電流是是75%In；IECSTD

22、保險絲的保險絲的最大不熔斷電流是是100%In。同時也要求保險絲在超過限量的過載電流時能及時燒斷，其中同時也要求保險絲在超過限量的過載電流時能及時燒斷，其中:MinimumFusingCurrent:ULSTD保險絲的保險絲的最小熔斷電流在在200%In左右左右；IECSTD保險絲的保險絲的最小熔斷電流在在210%左右。左右。ColdHOT17Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.選選用用保保險險絲絲的的重重要要參參數數(Fuseselectionfactor

23、s)選擇的保險絲是主要或次要的保護元選擇的保險絲是主要或次要的保護元件件?(FuseforPrimaryorSecondaryProtection?)1。額定電額定電流流(Ratedcurrent)(Minimumfuserating)=In2。額定電壓額定電壓(Ratedvoltage)AC/DC3。應用環境應用環境温度温度(Ambienttemperature)4。電壓電壓降降(Voltagedrop)5。熔。熔斷斷特性特性(Fusingcharacteristics)-時間時間/電電流特性流特性(TCcurves)6。遮斷遮斷/分分斷斷能力能力(Breaking/Interrupting

24、Capacity)7。熔化。熔化熱熱能值能值(MeltingIt)8。結構結構特特徵徵(Structure)-外形尺寸外形尺寸-安安裝裝型式型式18Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.额定额定電電流流RatedCurrent(In)額定電額定電流流In=Irmax/(Frf*Tdf)最大最大/重載工作電重載工作電流流(maxoperatingcurrentIrmax*)ULre-ratingfactor:Frf-0.75IECre-ratingfactor:

25、Frf-1Temperaturede-ratingfactor,TdfrefertotemperaturecurveA,BorCUL規格保險絲規格保險絲：In=Ir/(Frf*Tdf)IEC規格保險絲規格保險絲:In=Ir/Tdf計算的計算的In是是Absolute最小的最小的In額定電額定電流值可選或流值可選或往上往上選選用最用最佳適用佳適用的的In额额定定電電流值。流值。19Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.應用環應用環境温度境温度(AmbientTe

26、mperature)UL/IEC保險絲保險絲的各项要求都的各项要求都是指在室温是指在室温條條件下件下-250C時時應用環應用環境温度境温度對保險絲對保險絲的的特性特性是有是有很大的很大的影影響響!温度折减率温度折减率-TdfAmbientTemp:referstotheairtemperatureimmediatelytothevicinityoffuse.(Note:AttheworstConditionsuchasBurnIn,hightemptest,etc.)20Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse

27、,Inc.All rights reserved.實例:應用電壓:12 V DC應用最大/重載電流:1A max 環境溫度緊鄰保險絲:80C 脈衝電流:20A 30uSec.*短路電流短路電流:35Amax.at12V保險絲種類:1206 size TFF應用最大電流是應用最大電流是1.0A就將此值帶入下述公式就將此值帶入下述公式:Tdf:0.75*(0.70)Example:21Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.Example:Steadystatecu

28、rrent22Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.應用最大電流(Irmax)1.0ACat.FuseRating=-=-0.75x溫度折減率溫度折減率(Tdf)80C0.75x0.70Cat.FuseRating=1.91A計算值計算值-Absoluteminimumfuseratingcanbeselected.(可從可從1206size的的466or468系列系列2A以上安培數以上安培數,請參考表請參考表(一一)。)表表(一一)P/NRatingVolt

29、ageMeltingI2t04660022.0A63V0.2326A2Sec046602.52.5A32V0.3516A2Sec04660033.0A32V0.5760A2Sec04680022.0A63V0.506A2Sec04680033.0A32V1.270A2SecExample:(Continue)23Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.额定额定電壓電壓RatedVoltage(Vr）保險絲的保險絲的额定额定電壓電壓應應大大於於或等或等於於應用電應

30、用電路路電壓電壓(Vr標標示在保險絲目錄上示在保險絲目錄上)正常正常負載時負載時额定额定電壓對電壓對保險絲保險絲影影響響很小很小過載過載熔熔斷時斷時额定额定電壓電壓對對保險絲保險絲有影有影響響24Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.FUSING Basics:Hotspot温度温度Temperature(C)負載電流時的溫度負載電流時的溫度PCBSn锡球锡球PCBInIInMeltingPoint25Confidential and Proprietary

31、to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.t=0t=1fusingtomeltingfusing Basic Fusing Process(保險絲熔斷過程保險絲熔斷過程)26Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.t=1t=3arcingcontinuedependedontheIandV，Arcingendt=2,arcingstartingBasicFusingProcess(保險絲熔

32、斷過程保險絲熔斷過程)27Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.28Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.保險絲的電壓降說明保險絲的電壓降說明保險絲的電壓降是的電壓降是保險絲在額定電流條件下，其兩在額定電流條件下，其兩端的電壓降。它反映了端的電壓降。它反映了保險絲的內阻，其值不應過的內阻，其值不應過大。若將內阻（電壓降）過大的

33、大。若將內阻（電壓降）過大的保險絲安裝在電路安裝在電路中，它將影響電路的系統參數，使得電路不能正常中，它將影響電路的系統參數，使得電路不能正常工作。標準對電壓降不僅有其值的上限規定，而且工作。標準對電壓降不僅有其值的上限規定，而且對其一致性也作了規定。對其一致性也作了規定。29Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.時間時間/電電流特性流特性Time/CurrentCharacteristic承受承受過電過電流流時時,電電流流與熔斷時間與熔斷時間的的關係關係It

34、isacharacteristicsdeterminehowfastafuserespondstoover-currents.Over-currentisdividedintooverloadsandshortcircuits.UL和和IEC的的熔斷熔斷特性是特性是完完全不同的全不同的30Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.UL/CSA248-14規格規格ULVsIEC60127規格（）規格（）31Confidential and Proprietary t

35、o Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.AGENCYAPPROVALSUL/CSA248-14ListedCompliedUL/CSA248-14Recognized-ManufacturerIEC60127Certifyagency:VDE,BSI,SEMKO,TUV,NemKoMETIPSEMarkingCCCChinaSafetyperIECK-markKoreanSafety32Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.A

36、ll rights reserved.時間時間vs.電流曲線電流曲線:(Timevs.Currentcurve)T/CCurve是一個供是一個供設計參考用設計參考用的工具而不是保險絲的規範的工具而不是保險絲的規範是保險絲一個的是保險絲一個的平均熔斷時間曲線圖平均熔斷時間曲線圖.實際熔斷時間必須考量實際實際熔斷時間必須考量實際供應電壓供應電壓.33Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.如何看讀時間如何看讀時間/電流曲線電流曲線(HowtoreadtheTCcur

37、ve)先選先選3A曲線曲線.找出找出3曲線與曲線與6A線交叉點線交叉點.後再往後再往Y軸讀取相應時間軸讀取相應時間-0.1seconds.18012357.51534Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.遮斷遮斷/分分斷斷能力能力(Breaking/InterruptingCapacity)在額定電壓條件下,保險絲能夠安全地分斷預期的電流且沒有對環境的損害.(Interrupting rating also knownasBreakingCapacityors

38、hortcircuitrating,theinterruptingratingisthemaximumapprovedcurrentwhichthefusecanSAFELYinterruptatratedvoltage.)保險絲最重要的安全指標(Theword“safely”heremeans that there should be no significant damage to the fuse housing nor to the surroundings as a result of arcing or molten metal emerging from the fuse.)短路

39、短路時時保險絲保險絲能安全分能安全分斷斷的最大的最大短路電短路電流流IEC STD Fuse Type有分高分斷(High Breaking Capacity)，中分斷(Enhance Breaking Capacity)和低分斷(Low Breaking Capacity)保險絲.35Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.遮斷遮斷/分分斷斷能力能力(Breaking/InterruptingCapacity)UL248-14規定的分斷能力規定的分斷能力:12

40、5VAC條件下條件下ULListed保險絲必須能切斷保險絲必須能切斷10,000A for Subminiature fuse(2AG)的電流的電流;250VAC條件下保險絲必須能切斷的電流如下條件下保險絲必須能切斷的電流如下:保險絲的額定電流保險絲的額定電流額定分斷能力額定分斷能力01A 35A1.13.5A100A3.69A200A10.115A750A15.130A1500ARemark:Recognized認證的保險絲直接參考製造商的認證的保險絲直接參考製造商的InterruptingRating規格規格36Confidential and Proprietary to Littelf

41、use,Inc.2006 Littelfuse,Inc.All rights reserved.遮斷遮斷/分分斷斷能力能力(Breaking/InterruptingCapacity)IEC127規定的分斷能力規定的分斷能力:250VAC條件下的分斷能力保險絲條件下的分斷能力保險絲-低分斷(LBC)必須能安全切斷必須能安全切斷35AMINIMUM或或它的它的10In中的最中的最大的電流大的電流;中分斷(EBC)必須能安全切斷必須能安全切斷150A的電流的電流;高分斷(HBC)必須能安全切斷必須能安全切斷1500A的電流的電流37Confidential and Proprietary to L

42、ittelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.EXAMPLE:(continue)0466seriesInterruptingrating50A63VAC/DCfor0.52.0A0466seriesInterruptingrating50A32VAC/DCfor2.53A0466seriesInterruptingrating50A24VAC/DCfor45A0468seriesInterruptingrating35A63VAC/DCfor2A0468seriesInterruptingrating50A32VAC/DCfor3

43、A38Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.熔化熔化熱熱能值能值(MeltingI2t)切切斷保險絲斷保險絲所需的所需的熱熱能量值能量值*(is a direct measure for the energy required to blow the fuse-element.)often,the fuse nominal melting It Method of fuse selection is applied to those applications

44、in which the fuse MUST sustain large current pulses of a short duration.選選用用保險絲保險絲规格的重要参数规格的重要参数(mostimportantfuseselectionfactor)防疲勞防疲勞,多次的擴散多次的擴散,氧化氧化(prevent de-grade,and oxidize,etc.)力特對每一種小型保險絲给出了Fuse Nominal熔化I2t值清除I2t=熔化I2t+飛弧I2t Clearing I2t=Melting I2t+Arcing I2t *Ratio 22%=Pulse I2t/Fuse M

45、elting I2t *Select either F-fast-acting or T-time lagged fuse*Thesehigh-energycurrentsarecommoninmanyapplicationsandaredescribedbyavarietyofterms,suchas“surgecurrent”,“start-upcurrent”,“Inrushcurrent”,andothersimilarcircuit“transients”thatcanbeclassifiedingeneralcategoryof“PULSES.”Pulsecurrenti.e.af

46、lowofrepetitivecurrentpulses.39Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.PulseIt=ip(t)dt=ip(t)0SafetyfactorisLessthan22%=PulseIt/FuseNominalMeltingItORFuse minimum Melting It=Pulse It /22%40Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,In

47、c.All rights reserved.I2tofanArbitraryPulse-ConceptuallyI2t=areaunderi2(t)curvei(t)Time(t)Current(A)t t1 1t t2 2i2(t)Time(t)Current(A)t t1 1t t2 2i2(t)41Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.MeltingI2tMeltingI2tisanindexthatcharacterizestheenergyrequi

48、redtomeltafuseelement.MeltingI2tvaluesareempiricallymeasuredasshown:Current(A)Timemelting timearcing timeElement melted,Arcing beginsIntegrated to calculateMelting I2t42Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.ExampleofInrushCurrentIp2Ip1Ip3t1t2t3t4t5Ir=

49、4.5A43Confidential and Proprietary to Littelfuse,Inc.2006 Littelfuse,Inc.All rights reserved.ExampleofInrushIp1=25AIp2=20AIp3=25AT1=3mSecT2=10SecT3=3mSecT4=1hourT5=5mSecPulseI2t1=Ip1xIp1xt1=25x25x3mSec=1.875A2SecPulseI2t2=Ip2xIp2x(t3-t2)=20 x20 x3mSec=1.2A2Sec.PulseI2t3=Ip3xIp3x(t5t4)=25Ax25Ax5mSec=

50、3.125A2SecTotal Pulse I2t=6.2A2Sec(3.1A2Sec)Fuse Melting I2t=Total Pulse I2t/0.22 100,000 cycles=28.2A2Sec(14.1A2Sec)Fuse rating,In=Ir/(safety factor*Temperature factor)ULfactor=0.75,IECfactor=1,Temperature=100CFuserating,In=4.5/(0.75x0.9)=6.67AforULtypefuseminimum.In=4.5/(1x0.9)=5AforIECtypeminimum