電容器容量和允許誤差:
電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)器(qi)儲存電(dian)(dian)(dian)荷(he)的(de)(de)(de)(de)能(neng)力,常用(yong)的(de)(de)(de)(de)單(dan)位(wei)(wei)是F、μF、pF。電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)器(qi)上標(biao)有的(de)(de)(de)(de)電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)數(shu)是電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)器(qi)的(de)(de)(de)(de)標(biao)稱(cheng)(cheng)容(rong)(rong)(rong)(rong)(rong)量(liang)。電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)器(qi)的(de)(de)(de)(de)標(biao)稱(cheng)(cheng)容(rong)(rong)(rong)(rong)(rong)量(liang)和它(ta)(ta)(ta)的(de)(de)(de)(de)實際容(rong)(rong)(rong)(rong)(rong)量(liang)會有誤差。常用(yong)固定(ding)電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)允許誤差的(de)(de)(de)(de)等級見(jian)表2。常用(yong)固定(ding)電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)的(de)(de)(de)(de)標(biao)稱(cheng)(cheng)容(rong)(rong)(rong)(rong)(rong)量(liang)系列見(jian)表3。一般,電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)器(qi)上都直接寫出其容(rong)(rong)(rong)(rong)(rong)量(liang),也有用(yong)數(shu)字(zi)(zi)來標(biao)志容(rong)(rong)(rong)(rong)(rong)量(liang)的(de)(de)(de)(de),通常在(zai)容(rong)(rong)(rong)(rong)(rong)量(liang)小于(yu)10000pF的(de)(de)(de)(de)時候(hou),用(yong)pF做(zuo)單(dan)位(wei)(wei),大(da)于(yu)10000pF的(de)(de)(de)(de)時候(hou),用(yong)μF做(zuo)單(dan)位(wei)(wei)。為了簡便起(qi)(qi)見(jian),大(da)于(yu)100pF而小于(yu)1μF的(de)(de)(de)(de)電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)常常不注(zhu)單(dan)位(wei)(wei)。沒有小數(shu)點(dian)的(de)(de)(de)(de),它(ta)(ta)(ta)的(de)(de)(de)(de)單(dan)位(wei)(wei)是pF,有小數(shu)點(dian)的(de)(de)(de)(de),它(ta)(ta)(ta)的(de)(de)(de)(de)單(dan)位(wei)(wei)是μF。如有的(de)(de)(de)(de)電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)上標(biao)有“332”(3300pF)三位(wei)(wei)有效數(shu)字(zi)(zi),左起(qi)(qi)兩位(wei)(wei)給出電(dian)(dian)(dian)容(rong)(rong)(rong)(rong)(rong)量(liang)的(de)(de)(de)(de)第一、二(er)位(wei)(wei)數(shu)字(zi)(zi),而第三位(wei)(wei)數(shu)字(zi)(zi)則表示在(zai)后(hou)加0的(de)(de)(de)(de)個(ge)數(shu),單(dan)位(wei)(wei)是pF。
額(e)定工(gong)作(zuo)電(dian)(dian)(dian)(dian)壓(ya):在規定的(de)(de)(de)工(gong)作(zuo)溫度范圍(wei)內,電(dian)(dian)(dian)(dian)容(rong)長期可靠地工(gong)作(zuo),它能承受(shou)的(de)(de)(de)大直(zhi)流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya),就是(shi)電(dian)(dian)(dian)(dian)容(rong)的(de)(de)(de)耐壓(ya),也叫(jiao)做電(dian)(dian)(dian)(dian)容(rong)的(de)(de)(de)直(zhi)流(liu)(liu)工(gong)作(zuo)電(dian)(dian)(dian)(dian)壓(ya)。如果在交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)路中,要注意(yi)所加的(de)(de)(de)交(jiao)流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)大值不能超過電(dian)(dian)(dian)(dian)容(rong)的(de)(de)(de)直(zhi)流(liu)(liu)工(gong)作(zuo)電(dian)(dian)(dian)(dian)壓(ya)值。
絕緣電阻:
由于電(dian)(dian)容兩極(ji)之(zhi)間的(de)(de)(de)介質不(bu)是(shi)絕對的(de)(de)(de)絕緣(yuan)體,它的(de)(de)(de)電(dian)(dian)阻不(bu)是(shi)無限大(da),而是(shi)一個有限的(de)(de)(de)數值(zhi),一般在1000兆歐(ou)以上,電(dian)(dian)容兩極(ji)之(zhi)間的(de)(de)(de)電(dian)(dian)阻叫做絕緣(yuan)電(dian)(dian)阻,或者叫做漏電(dian)(dian)電(dian)(dian)阻,大(da)小是(shi)額定工作(zuo)電(dian)(dian)壓(ya)(ya)下(xia)的(de)(de)(de)直流(liu)電(dian)(dian)壓(ya)(ya)與通過(guo)電(dian)(dian)容的(de)(de)(de)漏電(dian)(dian)流(liu)的(de)(de)(de)比(bi)值(zhi)。漏電(dian)(dian)電(dian)(dian)阻越(yue)小,漏電(dian)(dian)越(yue)嚴重。電(dian)(dian)容漏電(dian)(dian)會(hui)引起能(neng)量(liang)損耗,這種損耗不(bu)僅影響電(dian)(dian)容的(de)(de)(de)壽命,而且會(hui)影響電(dian)(dian)路的(de)(de)(de)工作(zuo)。因此,漏電(dian)(dian)電(dian)(dian)阻越(yue)大(da)越(yue)好。
介質損耗:
電(dian)(dian)(dian)容器(qi)在(zai)電(dian)(dian)(dian)場作用(yong)下消(xiao)耗(hao)的(de)(de)能量,通(tong)常用(yong)損(sun)耗(hao)功率和電(dian)(dian)(dian)容器(qi)的(de)(de)無(wu)功功率之比(bi),即(ji)損(sun)耗(hao)角(jiao)的(de)(de)正切值表示(shi)。損(sun)耗(hao)角(jiao)越大,電(dian)(dian)(dian)容器(qi)的(de)(de)損(sun)耗(hao)越大,損(sun)耗(hao)角(jiao)大的(de)(de)電(dian)(dian)(dian)容不(bu)適于高(gao)頻(pin)情況下工作。
電容器參數相關鏈接:
產品注釋與說明 薄膜電容器的結構 薄膜電容器的標準體系及術語 GBT14472-1998固定電容器標準 電容器的分類、結構和特點