電容器在壓(ya)力(li)校驗儀的產(chan)品(pin)中(zhong)的重要性

識讀電容器參數

電(dian)容器是一種可存儲電(dian)能(neng)的(de)元(yuan)件（儲能(neng)元(yuan)件），通常(chang)簡稱為(wei)電(dian)容。它與(yu)電(dian)阻器一樣(yang)幾乎(hu)每種電(dian)子產品(pin)中都應(ying)用了電(dian)容器，是十分常(chang)見(jian)的(de)電(dian)子元(yuan)器件之一。在(zai)壓力(li)校驗儀產品(pin)中也被(bei)廣泛(fan)應(ying)用。

圖為電路中(zhong)電容器(qi)的(de)電路圖形(xing)符號(hao)標(biao)(biao)志(zhi)。電路圖形(xing)符號(hao)可(ke)以(yi)體(ti)現電容器(qi)的(de)基本(ben)類型(xing)；文字(zi)標(biao)(biao)志(zhi)通常提供電容器(qi)的(de)名稱、序號(hao)及電阻值等參數信息(xi)。

圖 電(dian)路中電(dian)容(rong)器的(de)電(dian)路圖形符號標(biao)志

識讀電容器參數標志

電容器標(biao)注(zhu)參數通(tong)常采用直標(biao)法、數字(zi)標(biao)注(zhu)法及色環標(biao)注(zhu)法。

電容器(qi)電容量直標法(fa)的(de)識(shi)讀(du)

電容(rong)(rong)器(qi)(qi)(qi)通常(chang)使用(yong)直標法將一些代碼符號標注(zhu)在(zai)電容(rong)(rong)器(qi)(qi)(qi)的外(wai)殼(ke)上，通過不同的數(shu)字(zi)(zi)和(he)字(zi)(zi)母(mu)表示(shi)容(rong)(rong)量值及主要參(can)數(shu)。根據我國國家(jia)標準規定，電容(rong)(rong)器(qi)(qi)(qi)型號標志由6部分構成。圖為電容(rong)(rong)器(qi)(qi)(qi)參(can)數(shu)直標法的識讀。

圖電容器參數直(zhi)標(biao)法(fa)的(de)識讀

電容(rong)器(qi)直標(biao)法中相(xiang)關代碼符號的(de)含義見(jian)表(biao)。掌握這些符號對應的(de)含義，便可順(shun)利完成(cheng)直標(biao)電容(rong)器(qi)的(de)識讀。

表 電容器(qi)直(zhi)標法中相(xiang)關(guan)代碼(ma)符號的含(han)義

識讀電解電容器引腳極性(xing)

區分電解電容(rong)器(qi)的(de)引(yin)腳(jiao)極(ji)性一般(ban)可以(yi)從三個(ge)方面入手第(di)一種是(shi)根據(ju)外(wai)殼上的(de)顏色或(huo)符號(hao)標志識(shi)別第(di)二種是(shi)根據(ju)電容(rong)器(qi)引(yin)腳(jiao)長短或(huo)外(wai)部明(ming)顯標志識(shi)別第(di)三種是(shi)根據(ju)電路板符號(hao)或(huo)電路圖形符號(hao)識(shi)別。

一些電(dian)解(jie)電(dian)容器外殼(ke)上明顯(xian)標(biao)(biao)注有負(fu)(fu)極(ji)性引腳標(biao)(biao)志(zhi)，如(ru)“一"符(fu)號或黑色標(biao)(biao)記，通常帶有這些標(biao)(biao)志(zhi)的一端(duan)為電(dian)解(jie)電(dian)容器的負(fu)(fu)極(ji)性引腳，如(ru)圖所(suo)示。

圖(tu)根據(ju)顏(yan)色和(he)符號區分電(dian)解電(dian)容器的引(yin)腳極性

電(dian)解電(dian)容(rong)器(qi)未(wei)安裝(zhuang)之前，其(qi)引(yin)(yin)(yin)(yin)腳(jiao)(jiao)長度并不一(yi)致，其(qi)中(zhong)引(yin)(yin)(yin)(yin)腳(jiao)(jiao)較長的(de)為(wei)正(zheng)極(ji)(ji)性(xing)(xing)引(yin)(yin)(yin)(yin)腳(jiao)(jiao)。有(you)些電(dian)解電(dian)容(rong)器(qi)在正(zheng)極(ji)(ji)性(xing)(xing)引(yin)(yin)(yin)(yin)腳(jiao)(jiao)附(fu)近會有(you)明顯的(de)缺口，根據該類特(te)征區別電(dian)容(rong)器(qi)的(de)引(yin)(yin)(yin)(yin)腳(jiao)(jiao)極(ji)(ji)性(xing)(xing)十分(fen)簡(jian)單。圖4-25為(wei)根據引(yin)(yin)(yin)(yin)腳(jiao)(jiao)長短區分(fen)電(dian)解電(dian)容(rong)器(qi)引(yin)(yin)(yin)(yin)腳(jiao)(jiao)極(ji)(ji)性(xing)(xing)的(de)方法。

圖 根據引腳長短(duan)區(qu)分電解電容器引腳極性(xing)的(de)方法(fa)

若電(dian)(dian)解(jie)電(dian)(dian)容(rong)(rong)器安裝在電(dian)(dian)路板上,則在其附近通(tong)常會印有極性(xing)符號(hao)(hao)(hao)或電(dian)(dian)路圖(tu)形(xing)符號(hao)(hao)(hao),根據(ju)電(dian)(dian)路圖(tu)形(xing)符號(hao)(hao)(hao)標(biao)志(zhi)很(hen)容(rong)(rong)易識別引腳極性(xing).圖(tu)為根據(ju)電(dian)(dian)路板符號(hao)(hao)(hao)或電(dian)(dian)路圖(tu)形(xing)符號(hao)(hao)(hao)識別電(dian)(dian)解(jie)電(dian)(dian)容(rong)(rong)器引腳極性(xing)。

檢測電容器

檢測普通電容器

圖為(wei)待測的(de)普通電容器(qi)。

圖待測的普通電容器

檢測(ce)(ce)(ce)(ce)普(pu)通(tong)電(dian)(dian)容(rong)(rong)器時,可先根據(ju)普(pu)通(tong)電(dian)(dian)容(rong)(rong)器的標(biao)志信息識讀出待測(ce)(ce)(ce)(ce)普(pu)通(tong)電(dian)(dian)容(rong)(rong)器的標(biao)稱電(dian)(dian)容(rong)(rong)量,然后使用(yong)萬(wan)用(yong)表(biao)檢測(ce)(ce)(ce)(ce)待測(ce)(ce)(ce)(ce)普(pu)通(tong)電(dian)(dian)容(rong)(rong)器的實際電(dian)(dian)容(rong)(rong)量,最后將實際測(ce)(ce)(ce)(ce)量值與(yu)標(biao)稱值比較(jiao),從而(er)判別出普(pu)通(tong)電(dian)(dian)容(rong)(rong)器的好壞。

圖(tu)為(wei)數字萬用表檢測普通電(dian)容器電(dian)容量的方(fang)法。

圖數字萬用表檢測普通電容器電容量的(de)方法

補充說明：

在正常情(qing)況下,用(yong)萬用(yong)表檢(jian)測電(dian)(dian)容(rong)(rong)器時應有一固(gu)定(ding)的電(dian)(dian)容(rong)(rong)量(liang),并且接近標稱值.若實測電(dian)(dian)容(rong)(rong)量(liang)與標稱值相差(cha)較大,則說明所測電(dian)(dian)容(rong)(rong)器損(sun)壞(huai)。

另(ling)外需(xu)要注意(yi),在用(yong)萬(wan)用(yong)表檢測電容(rong)器(qi)的(de)電容(rong)量時,所(suo)測電容(rong)器(qi)的(de)電容(rong)量不可超過萬(wan)用(yong)表的(de)量程(cheng)范圍(wei),否則測量結果不準確,無法判(pan)斷好壞。

如(ru)果(guo)需(xu)要(yao)精確測(ce)量(liang)電(dian)容(rong)器的電(dian)容(rong)量(liang)(萬用(yong)表(biao)只能(neng)粗略測(ce)量(liang)),則需(xu)使用(yong)專用(yong)的"電(dian)感/電(dian)容(rong)測(ce)量(liang)儀(yi)"。圖4-29為使用(yong)專用(yong)測(ce)量(liang)儀(yi)檢測(ce)普通電(dian)容(rong)器電(dian)容(rong)量(liang)的方法(fa)。

檢測電解電容器

檢(jian)(jian)測電(dian)(dian)解(jie)電(dian)(dian)容(rong)(rong)器(qi)(qi)是(shi)否正(zheng)常有(you)兩種方(fang)法:一種是(shi)直(zhi)接(jie)檢(jian)(jian)測電(dian)(dian)解(jie)電(dian)(dian)容(rong)(rong)器(qi)(qi)的(de)電(dian)(dian)容(rong)(rong)量(liang);另一種是(shi)通過電(dian)(dian)阻測量(liang)的(de)方(fang)法檢(jian)(jian)測電(dian)(dian)解(jie)電(dian)(dian)容(rong)(rong)器(qi)(qi)充放電(dian)(dian)的(de)性能。

檢(jian)測電(dian)解(jie)電(dian)容器的電(dian)容量

圖為待測的電解電容器

圖待測的電解電容器

檢(jian)測(ce)(ce)前，首(shou)先識(shi)別待測(ce)(ce)電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容(rong)器的引腳極性，然后用電(dian)(dian)(dian)阻器對電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容(rong)器進行放電(dian)(dian)(dian)操作，以避免電(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)容(rong)器中存有殘留電(dian)(dian)(dian)荷(he)而影響(xiang)檢(jian)測(ce)(ce)結果，如圖所示。

圖(tu) 識別待測電(dian)解(jie)電(dian)容器的(de)引腳(jiao)極性并進(jin)行放電(dian)操(cao)作(zuo)

放(fang)電操(cao)作完成后，使(shi)用數字萬(wan)用表檢測(ce)電解電容器(qi)的電容量，即(ji)可判(pan)斷待測(ce)電解電容器(qi)性能的好(hao)壞，如圖所(suo)示。

圖使用數字萬用表檢測電(dian)解電(dian)容(rong)器的電(dian)容(rong)量

補充說明：

電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容(rong)器的(de)放電(dian)(dian)(dian)(dian)(dian)操作主(zhu)要是針對(dui)大(da)容(rong)量(liang)電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容(rong)器，由于大(da)容(rong)量(liang)電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容(rong)器在工作中可(ke)能會(hui)(hui)有很多電(dian)(dian)(dian)(dian)(dian)荷，如短(duan)路，則會(hui)(hui)產生很強的(de)電(dian)(dian)(dian)(dian)(dian)流，引(yin)發電(dian)(dian)(dian)(dian)(dian)擊事故，如圖所示，容(rong)易損壞萬(wan)用(yong)表。應先用(yong)電(dian)(dian)(dian)(dian)(dian)阻放電(dian)(dian)(dian)(dian)(dian)后再進(jin)行檢測。一般(ban)可(ke)選用(yong)阻值(zhi)較小(xiao)的(de)電(dian)(dian)(dian)(dian)(dian)阻，將電(dian)(dian)(dian)(dian)(dian)阻的(de)引(yin)腳與電(dian)(dian)(dian)(dian)(dian)解電(dian)(dian)(dian)(dian)(dian)容(rong)器的(de)引(yin)腳相(xiang)連(lian)即可(ke)放電(dian)(dian)(dian)(dian)(dian)。

圖 大容(rong)量電解電容(rong)器(qi)的放電操作

在(zai)通(tong)常(chang)情況下，電(dian)解電(dian)容(rong)器(qi)(qi)的(de)工作電(dian)壓(ya)在(zai)200v以(yi)上，即使電(dian)容(rong)量(liang)(liang)比較小(xiao)也需要放電(dian)，如60μf/200v的(de)電(dian)容(rong)器(qi)(qi)，工作電(dian)壓(ya)較低，但電(dian)容(rong)量(liang)(liang)高于300μf，屬于大容(rong)量(liang)(liang)電(dian)容(rong)器(qi)(qi)。在(zai)實際(ji)應用(yong)中，常(chang)見的(de)大容(rong)量(liang)(liang)電(dian)容(rong)器(qi)(qi)1000μf/50v、60μf/400v、300μf/50v、60μf/200v等均為大容(rong)量(liang)(liang)電(dian)解電(dian)容(rong)器(qi)(qi)。

檢測電解電容器的充放電性能(neng)

圖為使用指針(zhen)萬用表檢(jian)測(ce)電解電容器充(chong)放電性能的方法。

圖 使用指針萬用表檢測(ce)電(dian)解電(dian)容器充(chong)放電(dian)性能的方法

補充說明：

檢測電(dian)解電(dian)容器(qi)的(de)正向直流電(dian)阻時，指(zhi)針(zhen)萬用表的(de)指(zhi)針(zhen)擺動速度較快(kuai)，檢測時應注意觀察。若萬用表的(de)指(zhi)針(zhen)沒有擺動，則表明該(gai)電(dian)解電(dian)容器(qi)已經(jing)失去電(dian)容量。

對于較大的(de)(de)電(dian)解(jie)電(dian)容器(qi)，可使用萬(wan)用表檢(jian)測(ce)充(chong)、放(fang)電(dian)過程對于較小的(de)(de)電(dian)容器(qi)，無(wu)須使用該(gai)方法檢(jian)測(ce)電(dian)解(jie)電(dian)容器(qi)的(de)(de)充(chong)、放(fang)電(dian)過程。