【正文】 檢流計(jì)來(lái)測(cè)量，所以電橋能夠精確地測(cè)量微小的電阻變化。10Ω ； 輸出阻抗 : 350177。 本設(shè)計(jì)采用全橋測(cè)量電路。雙積分式 ADC 就是一種首先將輸入的模擬信號(hào)變換成與其成正比的時(shí)間間隔，然后再在這段時(shí)間間隔內(nèi)對(duì)固定頻率的時(shí)鐘脈沖信號(hào)進(jìn)行計(jì)數(shù)的 A/D 轉(zhuǎn)換器，所獲得的計(jì)數(shù)值就是正比于輸入模擬信號(hào)的數(shù)字量。當(dāng) Vs=1 以后 ,S0斷開， A/D 轉(zhuǎn)換開始。 3) 量化編碼階段。 在 T2階段，將 CP（周期為 Tc）送入計(jì)數(shù)器計(jì)數(shù)， 課程設(shè)計(jì)說(shuō)明書 10 則 21 ic c REFT t VN T T V? ? ? 圖（ 5）雙積分 A/D裝換器原理圖 由此可見(jiàn)，計(jì)數(shù)器計(jì)數(shù)所獲得的數(shù)字量正比于輸入模擬電壓。 當(dāng)輸入第 11 ～ 19 個(gè)脈沖 時(shí)，仍由百分位片計(jì)數(shù)，而十分位片保持 “1”不變，即計(jì)數(shù)為 “11 ～ 19” ；當(dāng)輸入第 20 個(gè)脈沖時(shí)，個(gè)位片返回計(jì)數(shù) “0”狀態(tài)，其 Q3 輸出一個(gè)下降沿使十位片計(jì)數(shù) “2” ，即計(jì)數(shù)為 “ ” 。 由個(gè)位向十位進(jìn)位時(shí)步驟和上面一樣?？捎脕?lái)使顯示的數(shù)碼閃爍，或與某一信號(hào)同時(shí)顯示?？捎脕?lái)檢驗(yàn)數(shù)碼管、譯碼器和有關(guān)電路有無(wú)故障。 顯示數(shù)碼時(shí)，有些零可不顯示。 脈沖消隱（動(dòng)態(tài)滅燈）：輸出 RBO 和消隱輸入 BI 共用一個(gè)管腳，當(dāng)它用作輸出端時(shí)，與 RBI 配合，共同使冗余零消隱。百位為零（及百位的 A A A A0 全為低電平），而且被消隱（及百位的 RBI也為低電平），則百位的 RBO 和十位的 RBI 全為低（因?yàn)槎哌B在一起），其余數(shù)碼照常顯示。 2．在如此短的時(shí)間。 3．最后，在此對(duì)李棚老師的幫助表示深深的謝意。電阻應(yīng)變式傳感器是傳感器中應(yīng)用最多的一種，本設(shè)計(jì)采用全橋測(cè)量電路，使系統(tǒng)產(chǎn)生的誤差更小，輸出的數(shù)據(jù)更精確。例如研究顯示，隨著新型甜味劑的出現(xiàn)，消費(fèi)者可以識(shí)別1ppm 的偏差。為了確保過(guò)程的質(zhì)量與可再生性，梅 特勒 托力多所生產(chǎn)的 MinWeigh?為用戶提供了根據(jù)所使用稱重設(shè)備以及所需精確度計(jì)算與監(jiān)測(cè)最小重量的智能稱重功能。即使對(duì)于料罐的液位測(cè)量而言，提高使用超聲波的標(biāo)準(zhǔn)液位測(cè)量方法精確性的需求促使了基于稱重的解決方案的出現(xiàn)。人們恐怕想不出許多能夠與稱重一樣令人熟知與隨處可見(jiàn)的測(cè)量過(guò)程。目前，基于應(yīng)變規(guī)的測(cè)量系統(tǒng)用于水箱與鍋爐稱重、罐裝系統(tǒng)、稱重平臺(tái)與檢重秤。隨著最新工業(yè)開發(fā)成果的問(wèn)世，這些傳感器現(xiàn)已能夠在需要較高防護(hù)等級(jí)保護(hù)的危險(xiǎn)區(qū)域內(nèi)使用。 傳感器技術(shù)前景 當(dāng)今的稱重解決方案通常基于兩 種傳感器技術(shù)：應(yīng)變片技術(shù)與力補(bǔ)償技術(shù)。 課程設(shè)計(jì)說(shuō)明書 21 目 錄 ??? ?????????????? (5) ?????? ?????????????? (5) 傳感器 ??????????????????????????( 5) 三運(yùn)放大電路 ??????????????????????? (6) 間接比較型模式轉(zhuǎn)換器 AD ????????????????? (7) CT74LS290 計(jì)數(shù)器介紹 ??????????????????? (9) 集成二進(jìn)制 — 七段譯碼驅(qū)動(dòng)器介紹 ?????????????? (10) ????????????????????????? (12) ???????????????????????????? (13) ?????????????????? ??????? (16) g an employment tribunal clai Employment tribunals sort out disagreements between employers and employees. You may need to make a claim to an employment tribunal if: ? you don39。re clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click on nearest CAB. For more information about making a claim to an employment tribunal, see Employment tribunals. The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA. Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day。二十年的人生軌跡深深淺淺，突然就感覺(jué)到有些事情，非做不可了。 Then in high school, think don39。 A person39。嫌惡過(guò)自己的怯懦，最終卻發(fā)現(xiàn)有很多 緣分 ，有很多錯(cuò)過(guò)，好像冥冥之中真的已經(jīng)注定。 From the corner at the beginning of deep friendship。 課程設(shè)計(jì)說(shuō)明書 24 Baumgartner the disappointing news: Mission aborted. r plays an important role in this mission. Starting at the ground, conditions have to be very calm winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our daytoday weather lives. It will climb higher than the tip of Mount Everest ( miles/ kilometers), drifting even higher than the cruising altitude of mercial airliners ( miles/ kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence. The supersonic descent could happen as early as Sunda. The weatheThe balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform. Below, the Earth bees the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still,