電大《機電接口技術(shù)》期末考試重點復習題資料參考

1、電大機電接口技術(shù)期末考試重點復習題資料電大機電接口技術(shù)期末自測題輸入電壓過零，輸出電壓發(fā)生跳變。除此之外，輸出電壓保持不變。并希望輸入電壓大于零時輸出為高電平。則應選用（A 差動型電平檢測器比較器成穩(wěn)壓器。A 三端可調(diào)正電壓輸出C.固定型負電壓輸出一、選擇題1.要求電壓比較器僅在除此之外，輸出電壓保持不變。并希）。B同相輸入過零比較器C窗口D回差電壓比較器2.317為（）集B.固定型正電壓輸出D.三端可調(diào)負電壓輸出3.若希望電壓比較器在輸入小于+5V時輸出電壓為高電平，而在輸入大于十5V時輸出電壓為低電平。則應選用（）。A反相端輸入差動電平檢測器B過零比較器C窗口比較器D回差電壓比較器4.模擬

2、電壓比較器同運算放大器的主要區(qū)別是：模擬電壓比較器中的工作于（）。A.開環(huán)狀態(tài)B.負反饋狀態(tài)C.深度負反饋狀態(tài)D高電平狀態(tài)5.單向晶閘管有三個引腳：A、K和G，其中K為（）。A.陽極B.陰極C.控制極D門級6.AD202/AD204是基于（）原理的隔離放大器。A.變壓器耦合B.光電隔離C.繼電器隔離D,線性光電隔離7.運算放大器中的（）單元用于設(shè)置各級放大電路的靜態(tài)工作點。A.輸入級B.輸出級C.中間級D.偏置電路8.最早出現(xiàn)的電動機是（）。A.直流電動機B.交流電動機C.步進電動機D.直線電動機9.三相異步電動機改變同步轉(zhuǎn)速n0的方法是（）。A.調(diào)節(jié)轉(zhuǎn)子電阻B.調(diào)節(jié)定子電壓C.調(diào)節(jié)電源頻率D

3、.調(diào)節(jié)轉(zhuǎn)子電壓10.L290是一種（）-F4-|_L芯片。A.功率驅(qū)動芯片B.步進電機環(huán)形分配器C.細分電路D.轉(zhuǎn)速/電壓變換器二、簡答題1什么是光電耦合器件？光電耦合器件有什么特點？2隔離的實質(zhì)是什么？有哪些常用的隔離？3SPWM的基本思想是什么？產(chǎn)生SPWM控制信號的方法主要有哪三種？4常用的隔離方式有哪幾種?光電隔離的特點是什么?5三相步進電機的工作方式哪幾種?其中“單”、“雙”、“拍”各是什么意思?6單向晶閘管的導通條件是什么？7什么是直流電動機？它有哪些優(yōu)點？8什么是步進電機？9環(huán)形分配器的主要功能是什么？三、分析計算題圖11.寫出圖1所示電路的傳遞函數(shù)。四、設(shè)計電路1、用7805設(shè)

4、計一個輸出電壓為+7V的穩(wěn)壓電路。機電接口技術(shù)期末自測題答案一、選擇題1、B2、A3、A4、A5、B6、A7、D8、A9、C10、D二、簡答題1什么是光電耦合器件？光電耦合器件有什么特點？光電耦合器件將發(fā)光元件和受光元件組合在一起，通過電-光-電這種轉(zhuǎn)換，利用“光”這一環(huán)節(jié)完成隔離功能，使輸入和輸出在電氣上是完全隔離的。根據(jù)受光元件的不同可分為晶體管輸出型和晶閘管輸出型兩類。光電耦合器具有三個特點：信號傳遞采取電-光-電的形式，能夠避免輸出端對輸入端可能產(chǎn)生的反饋和干擾，抑制噪聲干擾能力強；具有耐用、可靠性高和速度快等優(yōu)點。2隔離的實質(zhì)是什么？有哪些常用的隔離？答：隔離的實質(zhì)是把引進的干擾通道

5、切斷，從而達到隔離現(xiàn)場干擾的目的。測控裝置與現(xiàn)場信號之間、弱電和強電之間，常用的隔離方式有光電隔離、繼電器隔離、變壓器隔離、隔離放大器等。另外，在布線上也應該注意隔離。SPWM的基本思想是什么？產(chǎn)生SPWM控制信號的方法主要有哪三種？答：SPWM的基本思想是：保持輸出脈沖電壓幅度不變，用調(diào)節(jié)脈沖的寬度和間隔實現(xiàn)其平均值接近正弦（同時改變U和f）。將此脈沖電壓加到電機上，所得到的電流波形接近于正弦波。就硬件方面講，產(chǎn)生SPWM控制信號的方法主要有三種：1）采用微處理器。2）采用專用大規(guī)模集成電路。3）采用微處理器和專用大規(guī)模集成電路相結(jié)合。常用的隔離方式有哪幾種?光電隔離的特點是什么?答：常用的

6、隔離方式有光電隔離、繼電器隔離、變壓器隔離、隔離放大器等。光電隔離是以光為媒介傳輸信號的器件，輸入和輸出在電氣上是完全隔離的。具有較高的電氣隔離和抗干擾能力。三相步進電機的工作方式哪幾種?其中“單”、“雙”、“拍”各是什么意思?答：三相步進電機一般有單三拍、六拍及雙三拍等工作方式?！皢巍?、“雙”、“拍”的意思是：“單指定子繞組每次切換前后只有一相通電；“雙”指每次有兩相定子繞組通電；“拍”指從一種通電狀態(tài)轉(zhuǎn)到另一種通電狀態(tài)。單向晶閘管的導通條件是什么？答:導通條件是指晶閘管從阻斷到導通的條件，條件是晶閘管的陽極加上正向電壓，同時在門極加上正向電壓。晶閘管一旦導通，門極對晶閘管就不起控制作用。什

7、么是直流電動機？它有哪些優(yōu)點？答：直流電動機是一種將直流電轉(zhuǎn)換為機械能的裝置，它的最大優(yōu)點是調(diào)速性能好，可以在寬廣的范圍內(nèi)實現(xiàn)無級調(diào)速；另外，它的起動轉(zhuǎn)矩大，過載能力強。直流電動機由定子和轉(zhuǎn)子兩大部分組成，在定子和轉(zhuǎn)子之間是空氣隙。什么是步進電機？答：步進電機是一種電磁式增量運動執(zhí)行元件，它可以將輸入的電脈沖信號轉(zhuǎn)換成相應的角位移或直線位移。因輸入的是脈沖信號，運動是斷續(xù)的，又稱脈沖電機或階躍電機。環(huán)形分配器的主要功能是什么？答：環(huán)形分配器的主要功能是把來自變頻信號源的脈沖序列按一定的規(guī)律分配后，經(jīng)過功率放大器的放大加到步進電機驅(qū)動電源的各項輸入端，以驅(qū)動步進電機的轉(zhuǎn)動。同時步進電機有正反轉(zhuǎn)的

8、要求，所以這種環(huán)形分配器的輸出既是周期的，又是可逆的。三、分析計算題2、解：不考慮符號，由圖1可列出下面的方程將后兩個公式帶入第一個公式，可得傳遞函數(shù)為：四、設(shè)計電路用7805設(shè)計一個輸出電壓為+7V的穩(wěn)壓電路。請您刪除一下內(nèi)容，O(C_C)0謝謝！!20XX年中央電大期末復習考試小抄大全，電大期末考試必備小抄，電大考試必過小抄AfterearninghisspursinthekitchensofTheWestin,TheSheraton,SensontheBund,andasprinklingofothertop-notchvenues,SimpsonLufinallygotthechanc

9、etobecomehisownbossinNovember20XX年.Sortof.TheShanghai-bornchefmightnotactuallyownCaliforniaPizzaKitchen(CPK)butheisinsolechargeofbothkitchenandfrontof-houseatthisSinanMansions stalwart.Its certainly a responsibility to be the hcehaedfand-yea “r-oltdhe 31tells Enjoy Shanghai.thentohavetomanagetherest

10、oftherestaurantaswell,Inhotels,forexample,thesejobsarestrictlydemarcated,soitsagreatopportunitytolearnhowabusinessoperatesacrosstheboard.“ItwaatasskthatmanagementbackinsunnyCaliforniaevidentlyfelthewasreadyfor,andavoteofconfidencefromacompanythat,todate,hasopened250outletsin11countries.Andforaddedpr

11、essure,theShanghaibranchwasalsoCPKsChinadebut.reit“waFsorsuabigstep,andunlikealltheirotherAsiaoperationsthatarefranchises,theydecidedtomanageitdirectlytobeginwith,“saysSimpson.Twoyeaagoaprivatefranchiseetookoverthelease,butthelinkstoCPKheadquartersarestillstrong,withamainland-basedbrandambassadoronh

12、andtoensurethebusinessadherestoitsethosofcreating“innovative,hear-tbhakedpizzas“,asliceofPRblurbthatSimpsoninsistslivesuptothehype.“Theyareveryinnovative,“he“Theproblemwithmostfastfoodplacesisthattheyusethesamesauceoneverypizzaandjustchangethetoppings.Everyoneofour16pizzasaucesisauniquerecipethathas

13、beenformulatedtocomplementthetoppingsperfectly.“ThelargelylocalcustomerbaseevnitdlyagreesandonSaturdayandSunday,atleast,theplaceisteeming.Thekids-eat-for-freepolicyatweekendsisundoubtedlyabigdraw,aswellasisthespacioussecond-floorlayoutoverlookedbyacanopyofgreenfromFuxingParkovertheroad.Thecompanyisa

14、lsofocusingonincreasingbrandrecognitionandinrecentyearshastakenpartinoutsideeventssuchastheregularCaliforniaWeek.Still,thestaarehonestenoughtoadmitthatbusinesscouldbebetter;asgood,infact,asinCPKdssecoutletinthepopularKerryParksideshoppingmallinPudong.“Sinant been easy for any of theMansionshasreally

15、struggledtogetthenumberofvisitorsthatwereenvisagedwhenitfirstopened,andithasntenants here, “ adds Simpson.We re plaanthniirndgoutlet in the city inthe better foot traffic.20XX年,andwewillprobablychooseashoppingmallagainbecauseofThetearoomsoncefrequentedbyCocoChanelandMarcelProustareuppingsticksandcom

16、ingtoShanghai,XuJunqianvisitstheParisianoutpostwithsweettreats.Onethingthecentury-oldParisiantearoomAngelinahasshownisthatlegendaryfashiondesignerCocoChanelnotonlyhadstyleandglamorbutalsoboastedgreattasteinfood,pastriesinparticular.OneofthemostpopulartearoomsinParis,Angelinaisfamousforhavingoncebeen

17、frequentedbycelebritiessuchasChanelandwriterMarcelProust.NowAngelinahaspackedupitsFrenchambience,efficientservice,andbeautiful,comfortingdessertsandflownthemtoShanghai.Attheflagshipdine-inandtake-outspaceinShanghai,everythingmimicstheoriginaltearoomdesignedfromthebeginningofthe20thcentury,inParis,th

18、eheightof“BelleEpoque“.Thepaintingsthewall,forexample,areexactlythesameastheonethatdepictsthelandscapeofsouthernFrance,thehometownoftheowner;andthesmalltablesareintentionalimitationsoftheonesthatCocoChaneloncesatateveryafternoonforhotchocolate.Thefamoushotchocolate,knownasLAfricain,isaluxuroiusmixtu

19、reoffourtypesofcocoabeansimportedfromAfrica,blendedinParisandthenshippedtoShanghai.Itssinfullsweet,richandthickasifputtingabarofmeltingchocolatedirectlyonthetongueandthefreshwhippedcreamonthesidemakesalight,butequallygratifyingcontrast.Itisalsosoldinglassbottlesastakeaway.ThesignatureMont-Blancchest

20、nutcakeconsistsofthreeparts:thepureedchestnutontop,thevanillacreamlikestuffing,andthemeringueasbase.Getallthreelayersinonescoop,notonlyforthedifferenttexturesbutalsovariousflavorsofsweetness.Thedesserthasmaintaineditspopularityforacentury,eveninacountrylikeFrance,perhapstheworldsmostcompetitiveplace

21、fordesserts.Amuchoverlookedpairing,istheParis-NewYorkchouxpastryandN226chocolateflavoredtea.Thechouxpastryisamouthfulofairypecan-flavoredwhippedcream,whilethetea,ablendofblackteasfromChinaandCeylon,cocoaandrosepetals,offersamoresubtlefragranceofflowersandchocolate.Orderingthesetwoitems,featuringamut

22、edsweetness,makesiteasierforyoutofitintoyourlittleblackdress.Breakfast,brunch,lunchandlightsupperarealsoservedatthetearoom,“ahubofmanycultures“andtakesin“amixofdifferentstylesofFrenchcuisines“,accordingtothemanagementteam.The-semicookedfoiegrasterrine,isseductiveanddeceptive.Itsgenerouslyseatthesize

23、andshapeofatoast,whiletheactualbriochetoastisbakedintoacurvedslicedippedwithfigchutney.Theflavor,however,ishonest:strong,smoothandsublime.Andyoudontactuallyneedthetoastforcrunchiness.Thisistheseasonforhighteas,withdaintycupsoffinechinaandlittlepastriesthatappealtobothvisualandphysicalappetites.Butth

24、ereisonehighteawithadifference,andPaulineD.Lohfindsoutjustexactlywhyitisspecial.EarlGreyteaandmacaronsareallverywellforthecrucialrecuperativebreakin-betweenintensiveboutsofholidayseasonshopping.Andforthosewhoprefersavorytosweet,thereisstilltheselectionofclassicChinesesnackscalleddimsumtosatisfyandsa

25、tiate.Highteaisamealtoeatwitheyeandmouth,anin-betweenindulgencethatshouldbelightenoughnottospoildinner,butsufficientlyrobusttotaketheedgeoffthehungerthatstrikeshoursafterlunch.TheafternoonteaspecialatShang-XiattheFourSeasonsHotelPudonghasjusttherightelements.Itisapamperingmeal,withtouchesofluxurytha

26、tmakethehighteasessionatreatinitself.Wholebabyabalonesarebraisedandthentoppedonashortcrustpastryshell,asortofChineseversionoftheWesternvol-au-vent,butclassier.Evenclassieristhedimsumstapleshrimpdumplingorhargow,upgradedwiththeadditionofsliversofmidnightdarktruffles.Thisisamastertouch,andchefSimonCho

27、i,whopresidesunchallengedatShang-Xi,hasscoredawinneragain.Sweetprawnsandaromatictruffleswhatsnottolove?Hismasterfulcraftsmanshipisexhibitedinyetanotherpastryasweetpastrythatisshapedtolooklikeawalnut,butwhichyoucanputstraightintothemouth.Itcrumblesimmediately,andtheslightlysweet,nuttymorselissoeasyto

28、eatyoullprobablyreachstraightforanhoetr.Myfavoriteisthedessertthatgoesbythenameyangzhiganlu,orambrosiafromthegods.Thehotelcallsitchilledmangocreamwithsago,pomeloandbirdsneit s nsestht e ingredient thatmadewithingredientsthatresonatewitheveryfemalesoul.Itdoestastelikeambrosia,withthesweet-sourfragranceofthemangoformingthefirstlayeroftasteandsens