单片机 温度控制系统 外文翻译 外文文献 英文文献 中英翻译

sthetransistorbeonandthenanalarmisgivenbythebuzzer.G.DriveCircuitAstepmotorisusedasthedrivedevicetocontrolthetemperature.Thefour-phaseandeight-beatpulsedistributionmodeisusedtodrivemotorandthesimpledelayprogramisusedtohandlethetimeintervalbetweenthepulsestoobtaindifferentrotationalspeed.Therearetwooutputstatesforthestepmotor.One:whenthetemperatureisovertheuppervalue,themotorrotatesreversely(tolowthetemperature),whilewhenlowerthanthelowerlimitvalue,themotorrotatesnormally(toraisethetemperature);besidesnotequalsthepresetvalue.Two:whenthetemperatureisatsomewherebetweenthetwoendsandequalsthepresetvalue,themotorstops.Thesestepsareusedtoachievethetemperaturecontrol.Inaddition,themotorspeedcanalsobeadjustedbyrelativebuttons.AsshowninFig.8,thecodedataisinputthroughportsA11~A8(beP2.3~P2.0)oftheAT89