隨著世界(jie)電子信息產業的(de)快(kuai)速發(fa)展(zhan),作(zuo)為電子信(xin)息產業基礎的(de)電子元件產業發(fa)展(zhan)也異常迅(xun)速。在電子(zi)制作中,要使用到許多(duo)不同的電子(zi)元件,而電子元件正進入以(yi)新型(xing)電子元件為主體(ti)的新一代元器件時代。想從事或了解電子信息產業的人,必須(xu)弄明白電子元件(jian)是什么,電子元件(jian)和電子器件(jian)的區別等關于電子元件(jian)的基礎知識(shi)。
電(dian)子元件是組成電(dian)子產品的基礎(chu),了(le)解常用的電子元件的種類、結(jie)構、性能(neng)并(bing)能(neng)正確選用(yong)是學習、掌握電(dian)子技術(shu)的基本。常用的電(dian)子元件有(you):電(dian)阻、電(dian)容(rong)、電(dian)感、電位器、變壓器等,就(jiu)安裝方式而言,目前(qian)可分為傳統安裝(又稱通孔(kong)裝即DIP)和表面安裝兩大類(即又稱SMT或(huo)SMD)。三極管(guan)、二極管稱為(wei)電子器(qi)件。
單面板:電路板只有一面用金屬處理;雙面板:電路板雙面都用(yong)金(jin)屬處理;
元件面:電路板上插元件的一面;焊接面:元件面的反面,存在(zai)許多焊盤(pan)以供焊接;
焊盤:PCB板(ban)上用于(yu)焊(han)接(jie)元件引腳(jiao)或金(jin)屬端(duan)的金(jin)屬部分(fen);層板:除電路板雙面外,電路板內層也有線路;
空焊:零件腳或引線腳與錫墊間由于某種原因沒有完成接合;假焊:類似于空焊,由于零件腳或引線腳與錫墊間焊(han)錫量太少,沒有達到(dao)接合標準(zhun);
冷焊:錫或錫膏在回風爐氣化后,在錫墊上仍(reng)有模糊的(de)粒狀附著物;橋接:零件腳與腳之間焊錫聯接短路;
金屬化孔:用于插元件或布明線的金屬化孔;連接孔:與金屬化孔相對,不用于插元件或布明線的金屬化孔;
極性元件:需定向插入電路板的元件;跪腳:零件腳(jiao)打折形成跪腳;錯件:零件放置的規格或種類與要求不符;
缺件:應放置零件的位置產生空(kong)缺;自檢:由工作的完成者依據規定的規則對該工作進行(xing)的檢驗(yan);
電子元件:指在工廠生產加工時不改變分子成分的成品。如電阻器、電容器、電感器。因為它本身不產生電子(zi),它(ta)對電壓(ya)、電流(liu)無控制和變換作(zuo)用,所以又稱無源器件。按分類標準,電子(zi)元(yuan)件可分為11個大類。
電子器件:指在工廠生產加工時改變了分子結構的成品。例如晶體管、電子管、集成電路。因為它本身能產生電子,對電壓、電流有控制、變換作用(放大、開關、整流、檢波、振蕩和調制等),所以又稱有源(yuan)器件。按分類標準,電子器件可(ke)分為12個大類,可歸納為真空電子器件和半導體器件兩大塊。【詳細>>】
電阻器在電路中起什么作用呢?
將電路中的(de)開關換為(wei)1個470歐姆的(de)電位器(qi)。旋(xuan)轉電位器(qi)的(de)轉柄,小燈泡的(de)亮度要(yao)隨(sui)著電阻值的(de)大小而改變。電阻值越(yue)大,小燈泡越(yue)暗(an)。這說明電阻器(qi)在電路中可(ke)以控制電流的(de)強弱。
電容器在電路中有什么作用呢?
用電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)代替開關。接通電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)時,我(wo)們(men)看到小(xiao)燈泡(pao)(pao)(pao)閃亮(liang)一(yi)下后(hou)就不再亮(liang)了。這是(shi)因為電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)在充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)瞬間(jian),電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)有電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。而(er)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過程很快結束(shu)了,電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)充(chong)(chong)滿電(dian)(dian)(dian)(dian)(dian)(dian)荷后(hou),電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)消失了。電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)容(rong)(rong)量越(yue)小(xiao),充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)所用時間(jian)越(yue)短暫,可見直(zhi)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)是(shi)不能通過電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)的(de)。若(ruo)將電(dian)(dian)(dian)(dian)(dian)(dian)源改為交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)源,小(xiao)燈泡(pao)(pao)(pao)將持續發光,若(ruo)交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)頻率可以(yi)變(bian)化,那么(me)在相同的(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓下,高(gao)頻率交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)較低頻率交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)更易于(yu)通過同一(yi)個電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)而(er)使(shi)小(xiao)燈泡(pao)(pao)(pao)更亮(liang)些。這些實驗可以(yi)說(shuo)明電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)在電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong),可以(yi)起“隔直(zhi)流(liu)(liu),通交(jiao)流(liu)(liu)”,“通高(gao)頻、阻(zu)低頻”的(de)作用。
晶體二極管在電路中有什么作用呢?
我們將晶體二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)接在電(dian)路中(zhong)的開(kai)關(guan)位置(zhi)上,燈(deng)泡發光,說明這(zhe)時二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)導通,二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的電(dian)阻(zu)(稱為正向電(dian)阻(zu))很小(xiao)。若將二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)兩極(ji)(ji)(ji)(ji)引腳對調,這(zhe)時小(xiao)燈(deng)泡不(bu)亮了。這(zhe)時二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的電(dian)阻(zu)(稱為反向電(dian)阻(zu))很大,電(dian)路中(zhong)幾乎沒有電(dian)流。這(zhe)個現象說明二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)有單向導電(dian)的特(te)性。利用二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)的這(zhe)個特(te)性,可使用二(er)極(ji)(ji)(ji)(ji)管(guan)(guan)(guan)進(jin)行檢波和整流。
1、通過電子元(yuan)器件(jian)網絡平臺找有工商注冊的正規公(gong)司;
2、了解供應商(shang)資質,三證是否齊全,業(ye)務員(yuan)的素質(zhi)及服(fu)務;
3、電(dian)子元(yuan)器件(jian)的型號細(xi)節部分(fen),如產品(pin)的誤差、材(cai)質、封(feng)裝、腳距、后(hou)綴字母(mu),細微環節要注(zhu)意(yi),避(bi)免出現產品不符退換貨,耽(dan)誤工(gong)程生產進度;
4、大型工廠注重高(gao)端質量,中小型工廠偏向成本和中高端質量;
5、在控制成(cheng)本(ben)的(de)問題上需要特別注(zhu)意(yi),切勿貪(tan)圖小便宜,正視便(bian)宜沒有好(hao)貨,可以選擇小批量采樣,初步確(que)認供應商的產品(pin)質量后(hou)再進(jin)行批量采購。【詳細>>】