Relatedconcepts
Introduction
1.Theratedpowerofthespeakerisalsocalledthenominalpower,whichmeansthatthespeakerisallowedtoinputthespeakerundertheconditionoftherateddistortionThemaximumelectricpower.ItsunitisvA(volt-ampere)orliner(watt).
2.Nominalpowerreferstothemaximumoutputpowerofthespeakerforalongtimewithoutdistortion,andthemaximumpowerreferstothemaximuminstantaneouspowerofthespeakerwithoutdamagingthespeaker.Themaximumloadcapacitythatcanbewithstood.
Accuratedefinition
Thedefinitionofoutputpoweristheenergyprovidedtotheoutsideworldbyenergyorequipmentperunittime.Thereisnospecificcalculationformulafortheoutputpower,unlessthemechanicalworkdonebythemotorperunittimeismeasured.BecauseaconsiderablepartoftheinputpowerisconvertedintoelectromagneticwavesormechanicalfrictionlossisalsorelatedtothephasedifferenceofACvoltageandcurrent.
Introductiontooutputpower
Amplifieroutputpower
Strictlyspeaking,thepowerindexofpoweramplifierisdividedintonominaloutputpowerandmaximuminstantaneousoutputpower.Theformeristheratedoutputpower,whichcanbeinterpretedasthemaximumvalueoftheoutputpowerwhentheharmonicdistortionchangeswithinthestandardrangeandcanworksafelyforalongtime;thelatterreferstothe"peak"outputpowerofthepoweramplifier,whichisinterpretedasthepoweramplifieracceptsWhenanelectricalsignalisinput,themaximumoutputpowerthatcanbewithstoodinstantaneouslyunderthepremiseofensuringthatthesignalisnotdamaged.
Mechanicaloutputpower
istheratiooftheenergyoutputfromvariousenergysourcesorenergyconversionequipment(suchaspowerandlightingequipment)totime,thatis,theenergyorequipmentdirectionperunittimeEnergyprovidedbytheoutsideworld.Itsunitsaregenerallywattsandkilowatts,andareoftenexpressedinvolt-ampereandkilovolt-ampereinpowersystems.
However,itshouldbenotedthatmanyhostsonthemarketaremarkedwiththeirpeakpower.Weneedtodiscountthisnumberby50%beforetheactualoutputpowercanrepresentthishost.Loadcapacity.
Speakeroutputpower
Thespeakeroutputpowerreferstothemaximumpowerthatthehometheatersetcanproduce.
Thesoundqualityisnotdirectlyrelatedtopower.Thepowerdeterminesthemaximumsoundintensitythatthespeakercanemit,anditfeelslikehowpowerfulthesoundofthespeakercanbe.
Accordingtointernationalstandards,therearetwolabelingmethodsforpower:ratedpower(RMS:sinewaverootmeansquare)andinstantaneouspeakpower(PMPOpower).Theformerreferstothemaximumelectricpowerthatdrivesan8Ωspeakerwithintheratedrangeandspecifiesthewaveformcontinuousanalogsignal,afteracertainintervalandrepeatsacertainnumberoftimes,thespeakerdoesnotcauseanydamage;thelatterreferstothemaximumpowerthatthespeakercanwithstandinashorttime.TheUnitedStatesFederalTradeCommissionstipulatedthepowercalibrationstandardin1974:Theeffectivewattagemeasuredwhentheharmonicdistortionislessthan1%intherangeof20to20000Hzistheeffectivewattagemeasuredwhendrivingan8Ωspeakerloadwithtwochannels.Foroutputpower,themarkedpoweristheratedoutputpower.Inordertocatertoconsumers'psychology,merchantsusuallymarktheinstantaneous(peak)power,whichisgenerallyabout8timestheratedpower.Therefore,whenpurchasingahometheaterpackage,theratedpowershallprevail.
Thepowerofthespeakerisnotthebiggerthebetter,theapplicationisthebest.Foranordinaryhomeuser’sroomofabout20squaremeters,therealpowerof60W(referstotheeffectiveoutputpowerofthespeaker30Wx2)Isenough,butthelargerthereservepowerofthepoweramplifier,thebetter,anditisbettertobemorethan2timestheactualoutputpower.Forexample,ifthespeakeroutputis30W,thepoweramplifiercapacityshouldbegreaterthan60W.FortheHiFisystem,thepoweramplifierpowerdrivingthespeakerisverylarge.
Motoroutputpower
Theinputpowerofthemotorisdefinedas:thevoltageacrossthemotormultipliedbythecurrentflowingthroughthemotor.Itdoesnotmeanthattheoutputpoweristrue.Theoutputpoweristhepowervaluethatthemotorconvertselectricalenergyintomechanicalenergy.Becausecurrentmotorsarenotideal,innormalworkduetotheactualcoilresistance,shaftfrictionandotherfactors,asmallpartoftheelectricenergywillbeconvertedintootherformsofenergy(mainlyheat)andlost,soTheoutputpowerislessthantheinputpower.Andthegreaterthepowerofthemotor,thesmallerthedifferencebetweenthetwo,andthesmallerthepower,thegreaterthedifference.
Maximumoutputpower
Maximumoutputpowerreferstothepoweramplifierwithinacertainharmonicdistortionindex(forMP3,MP4andotherelectronicproducts,themostcommonapplicationisheadphones)Whenalargeenoughsignalisinputandthevolumeandtonepotentiometersareadjustedtothemaximum,themaximumpowerthatthepoweramplifiercanoutputiscalledthemaximumoutputpower.Currently,themaximumoutputpowerofMP3onthemarketisgenerally10mW,20mW,40mW,etc.