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1、电子类的一些小问题Alittieproblemwithelectronics・TXTA,resistanceTheresistaneeisexpressedininthecircuit,asin:R1meansresistaneeof1.Themaineffectofresistanceinthecircuitis:shunt,current,partialpressure,offset,etc・1,theparameteridentification:theunitofresistanceistheo
2、hm(Q),multiplyingpowerunitsare:thousandQ(K),megohmQ(M),etc・Theconversionmethodis:1megaohm=1000euro=1000000euroTherearethreemethodsofparameterlabelingofresistance,namelythedirectstandardmethod,thecolorstandardandthenumberstandard.A,severalstandardmethodis
3、mainlyusedinSMTcircuitsuchassmallvolume,suchas:said47472x472Q(4.7K);104is100kB,colorringnotationisthemostused,forexample:Four-colorringresistaneefivecolorringresistance(precisionresistanee)Therelationshipbetweenthepositionandtheratioofresistaneeisshownin
4、thetable:Coloreffectivedigitratioallowsfordeviation(%)Silver/x0.01plusorminus10gold/x0.1plusorminus5black0+0/brown1xlOplusorminus1Red2,xlOOplusorminus2orange3xlOOO/yellow4xlO,000/green5xlOO,000plus0.5Blue6X1000000plusorminus0.2purple7X10000000/X100000000
5、/white9X1000000000/capacitanceThecapacitanceisusuallyexpressedininthecircuit(forexample,theC13indicatesacapacityof13).Capacitorsaremadeupoftwopiecesofmetal,separatedbyinsulatingmaterials・Thecharacteristicsofacapacitoraremainlythroughdirectcommunication.T
6、hesizeofthecapacitanceissaidtostoreelectricalenergy,thesizeofthecapacitanceeffectiscalledthecapacitivereactanceofacsignal,itisassociatedwiththefrequencyoftheacsignalandcapacitance・CapacitivereactanceXC二1/2PIcf(fisthefrequencyoftheacsignal,capacitancecsai
7、d)iscommonlyusedintelephonewithelectrolyticcapacitor,thekindsofceramicscapacitors,SMDcapacitors,monolithiccapacitors,tantalumcapacitors,polyestercapacitors,etc・Identificationmethod:therecognitionmethodofthecapacitorisbasicallythesameastheidentificationme
8、thodoftheresistanee,andthreekindsofdirectandlinear,color-codedandcounting・Thebasicunitofcapacitanceisexpressedinfarad(F),otherunitsTherearealso:themillimethod(mF),micromethod(uF),nF(nF),andpF(pF)・Amongthem:1farad二103mm二106
