最重要的发明电灯

Themostimportantinvention----LightIntroductionTheFirstElectricLightMadein1809byHunphryDavy,thisiscalledtheelectricarc.LateTheAmericanCharlesFranciesBrush

manufacturedsomecarbonarcs.TheInventor

ThomasEdisonexperimentedwiththousandsofdifferentmaterials,eventuallyproducedabulbthatcouldglowforover1500hours.汉弗莱·戴维爵士（法拉第旳老师）[ɑːk]电弧manufactured[,mænjə'fæktʃɚ]制造，加工（manufacture旳过去式）carbonarcs[电]碳弧bulb[bʌlb]电灯泡Therearethreekindsoflight.1.Incandescentlamp(白炽灯)：

a.Incandescentlamp（白炽灯）

b.Tungstenhalogenlamp（卤钨灯）

c.Halogenlamp（卤素灯）......2.Highintensitydischargelamp-HID（气体放电灯）

a.Fluorescentlamp（荧光灯）

b.Sodiumlamp（钠灯）

c.Metalhalidelamp（金属卤化物灯）......3.Others.

a.ElectrodelessLamp（高频无极灯）

b.LightEmittingDiode（发光二极管）......

Intheearly19thcentury，aBritishchemistmadethefirstarclampintheworldbyusing2023cells(电池）and2carbonrods.Butthiskindoflightistoostrong，itcannotbeusedinthehousebutonlyinthestreet.In1879

ByThomasEdison--anAmericaninventorThetemperatureofthefilament:3000℃Averagelifespan:1000hIt'salampwhichranksfirstintheproductionoftheworld.Butmanycountriesaretryingtostopusingit,becauseofitsheavypollution.Incandescentlamp（白炽灯）filament

['fɪləmənt]灯丝lifespan

寿命ComparetoIncandescent

lamp,thiskindoflamphaslongerlifespan(4000h)andhigher

lightefficiency.ItItisoftenusedinthemeetingroom,theexhibitionhallandthestage.TungstenHalogenLamp（卤钨灯）lightefficiency

光效率FluorescentLamp（荧光灯，俗称日光灯）Longlifespan:2500h~3500hHighlightefficiencyGoodcolorrenderingThetemperatureofthefilament:≤1000℃colorrendering显色性SodiumLamp(钠灯)Thehighestlightefficiency.FogpermeabilityLifespan:20230hBeusedinroads,airports,terminals,highways,etc.Fogpermeability

透雾性ElectrodelessLamp（高频无极灯）Verylonglifespan:40000h~80000hEnergysavingBrighter

So,itisoftenusedinsomeplaceswhichhavehigherrequirementsforsafety.Suchastunnels,subwaystationsandfactories.tunnels隧道LightEmittingDiode（发光二极管）Samefeaturesaselectrodelesslamp,butmoreenergysaving.Itissecurewhenitworkunderthelowthermalvoltage.Andit'ssurfacetemperaturelessthan60℃.low

thermalvoltage

低热电压