2023年全國(guó)碩士研究生考試考研英語(yǔ)一試題真題(含答案詳解+作文范文)_第1頁(yè)
已閱讀1頁(yè),還剩17頁(yè)未讀, 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說(shuō)明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡(jiǎn)介

1、<p>  畢業(yè)設(shè)計(jì)(論文)外文資料翻譯</p><p>  學(xué)院 (系): 電子電氣工程學(xué)院 </p><p>  專 業(yè): 電氣工程及其自動(dòng)化 </p><p>  姓 名: </p><p>  學(xué)

2、 號(hào): </p><p>  外文翻譯:WWW.ELECTRONICS-LAB.COM/PROJECTS/</p><p>  TEST/014/INDEX.HTM </p><p>  附 件:1.外文資料翻譯譯文;2.外文原文。 </p><p> 

3、 附件1:外文資料翻譯譯文</p><p>  LED顯示屏的數(shù)字電壓表</p><p><b>  來(lái)源:智能工具包</b></p><p><b>  1 引言</b></p><p>  這是一個(gè)很容易建立并且非常準(zhǔn)確和有用的數(shù)字電壓表。它被設(shè)計(jì)成一個(gè)面板儀表,可用于直流電源供應(yīng)器或其他需要

4、有一個(gè)準(zhǔn)確電壓指示的地方。該電路采用的ADC(模擬數(shù)字轉(zhuǎn)換器)集成電路CL7107由Intersil公司生產(chǎn)。該IC采用40引腳的情況下整合了所有必要的電路模擬信號(hào)轉(zhuǎn)換為數(shù)字,可以直接驅(qū)動(dòng)4個(gè)7段LED顯示。在IC中內(nèi)置的電路是數(shù)字轉(zhuǎn)換器,比較器,一個(gè)時(shí)鐘,一個(gè)解碼器和一個(gè)7段LED顯示驅(qū)動(dòng)器模擬。在這里它描述了一個(gè)可以顯示在0-1999電壓范圍的直流電壓電路。</p><p><b>  前面<

5、/b></p><p>  2 LED顯示屏數(shù)字電壓表技術(shù)規(guī)格 - 特征</p><p>  (1) 電源電壓:.............+ / - 5V(對(duì)稱)。</p><p>  (2) 電源要求:.............200mA(最大)。</p><p>  (3) 測(cè)量范圍:.............+ / - 0

6、-1,999V在四個(gè)范圍。</p><p>  (4) 精度:.................0.1%。</p><p><b>  (5) 特征:</b></p><p><b>  - 小尺寸。</b></p><p><b>  - 簡(jiǎn)易建筑。</b></

7、p><p><b>  - 成本低。</b></p><p><b>  - 簡(jiǎn)單的調(diào)整。</b></p><p>  - 易于讀取距離。</p><p>  - 很少的外部元件。</p><p>  3 數(shù)字電壓表的基本原則</p><p> 

8、 為了了解電路的運(yùn)作的原則,說(shuō)明ADC的集成電路工程是必要的。該集成電路具有以下非常重要的特點(diǎn):</p><p><b>  - 準(zhǔn)確性。</b></p><p><b>  - 抗干擾性。</b></p><p>  - 無(wú)需要一個(gè)采樣保持電路。</p><p>  - 它有一個(gè)內(nèi)置的時(shí)鐘

9、。</p><p>  - 它不需要精度高的外部元件。</p><p>  一個(gè)模擬數(shù)字轉(zhuǎn)換器(ADC),從現(xiàn)在起更好的稱為雙斜率轉(zhuǎn)換器或集成轉(zhuǎn)換器。這種類型的轉(zhuǎn)換器通常優(yōu)于其他類型,因?yàn)樗峁┝藴?zhǔn)確,簡(jiǎn)潔的設(shè)計(jì)和它可以將相對(duì)不重要的噪音變得非常可靠。如果將電路分兩個(gè)階段描述,該電路的操作將更好的理解。在第一階段的輸入集成電壓和最后階段的輸出集成電壓中有一個(gè)電壓與輸入電壓成正比。在預(yù)設(shè)的

10、時(shí)間結(jié)束時(shí),積分將到達(dá)內(nèi)部基準(zhǔn)電壓以及輸出電路會(huì)逐漸降低直至達(dá)到零參考電壓水平。第二個(gè)階段就是所謂的負(fù)斜率時(shí)期,其持續(xù)時(shí)間由第一階段積分器輸出而定。作為第一個(gè)操作時(shí)間是固定的,第二個(gè)變量的長(zhǎng)度就可以比較兩個(gè)這樣的輸入電壓,其實(shí)是相對(duì)于內(nèi)部參考電壓,其結(jié)果是編碼,然后發(fā)送到顯示。</p><p>  示意圖(固定16-11-09)</p><p>  7段顯示器引出線MAN6960</

11、p><p>  這一切聽(tīng)起來(lái)很容易,但實(shí)際上它是一系列非常復(fù)雜的操作,這些都是由ADC集成電路作出了很少的外部元件,幫助它們用來(lái)配置工作的電路。詳細(xì)的電路的工作原理如下。為了進(jìn)行測(cè)量,需要將電壓施加于電路的1和2點(diǎn),最后通過(guò)電路的R3,R4和C4應(yīng)用到集成電路的引腳30和31。從下圖你可知這是該集成電路的輸入(分別為高與低)。R1電阻的C1一起用來(lái)設(shè)置內(nèi)部振蕩器(時(shí)鐘),該設(shè)置約48Hz。在這個(gè)時(shí)鐘速率大約有三個(gè)不同

12、的每秒讀數(shù)。連接集成電路引腳33和34之間的電容已被選定,以彌補(bǔ)由內(nèi)部參考電壓帶來(lái)的誤差,并保持穩(wěn)定的顯示。電容C3和電阻R5在一起的電路是輸入電壓的集成電路,同時(shí)它可避免任何使電路更快的分裂輸入電壓,從而使錯(cuò)誤的可能性大大減少進(jìn)而使電路更穩(wěn)定。在沒(méi)有輸入電壓時(shí)電容器C5強(qiáng)迫儀器顯示為零。當(dāng)輸入為零時(shí)電阻R2和P1一起用來(lái)調(diào)整儀器在設(shè)置過(guò)程中顯示為零。電阻R6的控制電流允許流經(jīng)顯示,以便使電路在沒(méi)有損壞的前提下顯示充分的亮度。至于我們上

13、面已經(jīng)提到的芯片它能夠驅(qū)動(dòng)4個(gè)共陽(yáng)極LED顯示屏。這三個(gè)最右邊的顯示器相連,使他們可以顯示所有從0到9的數(shù)字,而從左邊第一個(gè)只能顯示數(shù)字1,當(dāng)電壓為負(fù)“-”</p><p><b>  背面</b></p><p>  4 數(shù)字電壓表印刷電路板的加工</p><p>  首先讓我們考慮建立一個(gè)印刷電路板上的電子電路的基礎(chǔ)知識(shí)。該印刷電路板是由

14、薄絕緣銅的導(dǎo)電復(fù)合材料薄層形成,這樣以形成電路之間的各組成部分的必要的導(dǎo)體。一個(gè)設(shè)計(jì)完善的印刷電路板是非常可取的,因?yàn)樗蟠蠹涌炝思庸?,并大大減少了決策失誤的可能性。為了保護(hù)印刷電路板在存儲(chǔ)過(guò)程中被氧化和保證它到達(dá)你所要求的完美的條件,在生產(chǎn)過(guò)程中將銅鍍錫的同時(shí)起表面還要覆蓋一層特殊的漆,這樣不僅防止了它被氧化,也使焊接更容易。</p><p>  焊接的部件,印刷電路板是建立你的電路的唯一的方式和你在做板時(shí)很大

15、程度上取決了你的成功或失敗。這項(xiàng)工作也并不是很困難,如果你堅(jiān)持有一些規(guī)則你應(yīng)該沒(méi)有問(wèn)題。在你使用電烙鐵時(shí),其功率不應(yīng)超過(guò)25瓦。它的尖應(yīng)該是好的,并且必須時(shí)刻保持清潔。為此我們特地準(zhǔn)備了一特制海綿并使其保持潮濕,這樣可以不時(shí)擦拭熱烙鐵尖,從而去除積累在它上面的殘?jiān)?lt;/p><p>  如果烙鐵尖不能清洗或更換,請(qǐng)勿用文件或砂紙弄臟或磨損其尖部。在市場(chǎng)上有許多不同類型的焊接劑,你應(yīng)該選擇一個(gè)優(yōu)質(zhì)的一個(gè)在其核心包含

16、必需的流量的焊接劑,以保證每次焊接時(shí)都能完美的接合。</p><p>  不使用助焊劑除了在你的焊接劑里已含有助焊劑。太多的流量可能會(huì)導(dǎo)致許多問(wèn)題,也是電路故障的主要原因之一。但如果您必須使用額外的流量,因?yàn)樗窃谀悴坏貌粚~線鍍錫的情況下,將起徹底清除干凈后你完成了你的工作。</p><p>  為了焊接組件正確,您應(yīng)該執(zhí)行下列操作:</p><p>  - 用

17、一小塊砂紙清潔清潔組件。</p><p>  - 彎曲組件使它們之間有一合適的距離并插入在印刷電路板中的正確地位組成部分。</p><p>  - 你有時(shí)可能會(huì)發(fā)現(xiàn)比起平常還會(huì)有重計(jì)部分,它將過(guò)于厚而不能進(jìn)入個(gè)人電腦印刷電路板的孔。在這種情況下使用的小型鉆孔略有放大。不要使孔太大,因?yàn)檫@將會(huì)使焊接困難。</p><p><b>  安置部分</b

18、></p><p>  印刷電路板尺寸:77,6毫米× 44,18毫米或35%的范圍內(nèi)做</p><p>  拿著熱鐵將其尖端放在組件的一角上,同時(shí)將焊錫絲末梢放在尖端的一個(gè)點(diǎn)上。烙鐵頭必須觸及略高于印刷電路板的地方。</p><p>  當(dāng)焊錫絲開(kāi)始融化和流動(dòng)等待它均勻覆蓋孔周圍的區(qū)域和通量癤并且焊料從下面流出。整個(gè)過(guò)程不應(yīng)超過(guò)5秒。清除烙鐵,讓焊

19、接劑自然冷卻不吹,或移動(dòng)組件。如果一切處理得當(dāng)則表面聯(lián)合處有一個(gè)光明的金屬質(zhì)感,其邊緣應(yīng)該是平滑的并且有一軌道面。如果焊料看起來(lái)暗淡無(wú)光,有裂痕的,或有一個(gè)氣泡的形狀,那么你虛焊了和你應(yīng)該清除焊接劑(用泵,或焊芯)然后重做它。</p><p>  注意不要過(guò)熱的軌道,因?yàn)樗呛苋菀讖钠潆娐钒迳辖獬龔亩鴵p壞電路板。</p><p>  在你焊接一個(gè)敏感元件時(shí),很好的做法是用一個(gè)長(zhǎng)鼻子鉗子夾著

20、電路板組件的邊緣進(jìn)行熱轉(zhuǎn)移但是那樣容易損壞組件。</p><p>  確保你不使用過(guò)多的焊料是必需的,因?yàn)槟阏诿爸徿壍蓝搪返娘L(fēng)險(xiǎn),特別是如果他們都非常接近時(shí)。</p><p>  當(dāng)你完成你的工作時(shí),切斷組件的多余部分和用適當(dāng)?shù)娜軇﹣?lái)徹底清除可能還留在電路板上的助焊劑殘留物。</p><p>  更換的電阻按照下表:</p><p> 

21、 0 - 2V............ R3 = 0歐姆1%</p><p>  0 - 20V........... R3 = 1.2千歐1%</p><p>  0 - 200V.......... R3 = 12千歐1%</p><p>  0 - 2000V......... R3 = 120千歐1%</p><p>  當(dāng)您完成所有

22、的電路板上焊接和您確信一切正常,可以插入在其位芯片。該IC是CMOS類型于是對(duì)靜電非常敏感。它有鋁箔包裹以防止靜電放電,并應(yīng)小心處理,以免損壞它。盡量避免用你的手接觸引腳,并且保持地面電路和你的身體電位在你插入的位置。</p><p>  電路連接到一個(gè)合適的電源ρ5伏直流電上,開(kāi)啟電源。在光顯示區(qū)應(yīng)立即形成一個(gè)數(shù)字。短路輸入(0V)和調(diào)整微調(diào)小屏幕顯示,直到完全去掉0。</p><p>

23、<b>  5 故障檢查簡(jiǎn)介</b></p><p>  檢查您可能造成的虛焊,跨越鄰近軌道或助焊劑殘留物的橋梁工作,通常會(huì)造成問(wèn)題。再次檢查所有的電路和外部連接,看看是否有一個(gè)錯(cuò)誤。</p><p>  看是否有任何組件丟失或錯(cuò)誤的地方插入:</p><p>  - 確保所有的兩極分化組件已被焊接正確。</p><p&

24、gt;  - 確保供應(yīng)具有正確的電壓,以正確的方式連接到你的電路上。</p><p>  - 檢查您的故障或損壞的部件項(xiàng)目。</p><p><b>  6 結(jié)論</b></p><p>  一個(gè)配備自動(dòng)檢查和校準(zhǔn)的電壓表減少了實(shí)驗(yàn)所校正的必要,因?yàn)樗且粋€(gè)偶爾為了更好的參考電壓而校正的參考單元。</p><p>

25、<b>  附件2:外文原文</b></p><p>  Led display digital Voltmeter </p><p>  source: Smart Kit</p><p>  front side</p><p>  Copyright of this circuit belongs to smart

26、 kit electronics. In this page we will use this circuit to discuss for improvements and we will introduce some changes based on original schematic</p><p>  General Description </p><p>  This is

27、an easy to build, but nevertheless very accurate and useful digital voltmeter. It has been designed as a panel meter and can be used in DC power supplies or anywhere else it is necessary to have an accurate indication of

28、 the voltage present. The circuit employs the ADC (Analogue to Digital Converter) I.C. CL7107 made by INTERSIL. This IC incorporates in a 40 pin case all the circuitry necessary to convert an analogue signal to digital a

29、nd can drive a series of four seven segment LED disp</p><p>  Technical Specifications - Characteristics</p><p>  Supply Voltage: ............. +/- 5 V (Symmetrical)</p><p>  Power

30、requirements: ..... 200 mA (maximum)</p><p>  Measuring range: .......... +/- 0-1,999 VDC in four ranges</p><p>  Accuracy: ....................... 0.1 %</p><p><b>  FEATURES&

31、lt;/b></p><p>  - Small size </p><p>  - Easy construction </p><p>  - Low cost.</p><p>  - Simple adjustment.</p><p>  - Easy to read from a distance.&

32、lt;/p><p>  - Few external components.</p><p>  How it Works </p><p>  In order to understand the principle of operation of the circuit it is necessary to explain how the ADC IC works.

33、 This IC has the following very important features:</p><p>  - Great accuracy.</p><p>  - It is not affected by noise.</p><p>  - No need for a sample and hold circuit.</p>&

34、lt;p>  - It has a built-in clock.</p><p>  - It has no need for high accuracy external components.</p><p>  Schematic (fixed 16-11-09)</p><p>  7-segment display pinout MAN6960&l

35、t;/p><p>  An Analogue to Digital Converter, (ADC from now on) is better known as a dual slope converter or integrating converter. This type of converter is generally preferred over other types as it offers acc

36、uracy, simplicity in design and a relative indifference to noise which makes it very reliable. The operation of the circuit is better understood if it is described in two stages. During the first stage and for a given pe

37、riod the input voltage is integrated, and in the output of the integrator at the </p><p><b>  back side</b></p><p>  All this sounds quite easy but it is in fact a series of very com

38、plex operations which are all made by the ADC IC with the help of a few external components which are used to configure the circuit for the job. In detail the circuit works as follows. The voltage to be measured is appli

39、ed across points 1 and 2 of the circuit and through the circuit R3, R4 and C4 is finally applied to pins 30 and 31 of the IC. These are the input of the IC as you can see from its diagram. (IN HIGH & IN LOW respecti&

40、lt;/p><p>  Construction </p><p>  First of all let us consider a few basics in building electronic circuits on a printed circuit board. The board is made of a thin insulating material clad with a

41、thin layer of conductive copper that is shaped in such a way as to form the necessary conductors between the various components of the circuit. The use of a properly designed printed circuit board is very desirable as it

42、 speeds construction up considerably and reduces the possibility of making errors.  To protect the board during storag</p><p>  Soldering the components to the board is the only way to build your circui

43、t and from the way you do it depends greatly your success or failure. This work is not very difficult and if you stick to a few rules you should have no problems. The soldering iron that you use must be light and its pow

44、er should not exceed the 25 Watts. The tip should be fine and must be kept clean at all times. For this purpose come very handy specially made sponges that are kept wet and from time to time you can wipe th</p>&l

45、t;p>  DO NOT use soldering flux apart from that which is already included in your solder. Too much flux can cause many problems and is one of the main causes of circuit malfunction. If nevertheless you have to use ext

46、ra flux, as it is the case when you have to tin copper wires, clean it very thoroughly after you finish your work.</p><p>  In order to solder a component correctly you should do the following:</p>&l

47、t;p>  - Clean the component leads with a small piece of emery paper.</p><p>  - Bend them at the correct distance from the component’s body and insert the component in its place on the board.</p>&

48、lt;p>  - You may find sometimes a component with heavier gauge leads than usual, that are too thick to enter in the holes of the p.c. board. In this case use a mini drill to enlarge the holes slightly. Do not make the

49、 holes too large as this is going to make soldering difficult afterwards.</p><p>  Parts placement</p><p>  PCB dimensions: 77,6mm x 44,18mm or scale it at 35%</p><p>  - Take the h

50、ot iron and place its tip on the component lead while holding the end of the solder wire at the point where the lead emerges from the board. The iron tip must touch the lead slightly above the p.c. board.</p><

51、p>  - When the solder starts to melt and flow wait till it covers evenly the area around the hole and the flux boils and gets out from underneath the solder. The whole operation should not take more than 5 seconds. Re

52、move the iron and allow the solder to cool naturally without blowing on it or moving the component. If everything was done properly the surface of the joint must have a bright metallic finish and its edges should be smoo

53、thly ended on the component lead and the board track. If the solder</p><p>  - Take care not to overheat the tracks as it is very easy to lift them from the board and break them.</p><p>  - When

54、 you are soldering a sensitive component it is good practice to hold the lead from the component side of the board with a pair of long-nose pliers to divert any heat that could possibly damage the component.</p>&

55、lt;p>  - Make sure that you do not use more solder than it is necessary as you are running the risk of short-circuiting adjacent tracks on the board, especially if they are very close together.</p><p>  -

56、 When you finish your work, cut off the excess of the component leads and clean the board thoroughly with a suitable solvent to remove all flux residues that may still remain on it.</p><p>  For the replacem

57、ent resistors follow the table below: </p><p>  0 - 2 V ............ R3 = 0 ohm 1%</p><p>  0 - 20 V ........... R3 = 1.2 Kohm 1%</p><p>  0 - 200 V .......... R3 = 12 Kohm 1%</p

58、><p>  0 - 2000 V ......... R3 = 120 Kohm 1%</p><p>  When you have finished all the soldering on the board and you are sure that everything is OK you can insert the IC in its place. The IC is CMOS

59、 and is very sensitive to static electricity. It comes wrapped in aluminium foil to protect it from static discharges and it should be handled with great care to avoid damaging it. Try to avoid touching its pins with you

60、r hands and keep the circuit and your body at ground potential when you insert it in its place.</p><p>  Connect the circuit to a suitable power supply ρ 5 VDC and turn the supply on. The displays should lig

61、ht immediately and should form a number. Short circuit the input (0 V) and adjust the trimmer P1 until the display indicates exactly «0».</p><p>  If it does not work </p><p>  Check y

62、our work for possible dry joints, bridges across adjacent tracks or soldering flux residues that usually cause problems. </p><p>  Check again all the external connections to and from the circuit to see if t

63、here is a mistake there.</p><p>  - See that there are no components missing or inserted in the wrong places. </p><p>  - Make sure that all the polarised components have been soldered the right

溫馨提示

  • 1. 本站所有資源如無(wú)特殊說(shuō)明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁(yè)內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒(méi)有圖紙預(yù)覽就沒(méi)有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫(kù)僅提供信息存儲(chǔ)空間,僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請(qǐng)與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。

評(píng)論

0/150

提交評(píng)論