電磁繼電器可(ke)以用(yong)低電(dian)壓、弱電(dian)流(liu)控(kong)制高電(dian)壓、強電(dian)流(liu)電(dian)路,還(huan)可(ke)實現(xian)遠距離(li)操縱和(he)生產(chan)自動(dong)化(hua),在現(xian)代生活(huo)中起著越(yue)來越(yue)重要的作用(yong)。
二、電磁繼電器的工作原理
繼(ji)電(dian)(dian)器,一(yi)般(ban)指的(de)(de)是(shi)電(dian)(dian)磁(ci)繼(ji)電(dian)(dian)器,也就是(shi)機械動作那(nei)種(zhong)。繼(ji)電(dian)(dian)器的(de)(de)作用(yong)本(ben)質是(shi)用(yong)一(yi)個(ge)(ge)回路(一(yi)般(ban)是(shi)小電(dian)(dian)流)去控(kong)制(zhi)另外一(yi)個(ge)(ge)回路(一(yi)般(ban)是(shi)大(da)(da)電(dian)(dian)流)的(de)(de)通斷(duan),而(er)且這個(ge)(ge)控(kong)制(zhi)過(guo)程(cheng)中,兩個(ge)(ge)回路一(yi)般(ban)是(shi)隔離(li)的(de)(de),它的(de)(de)基本(ben)原理,是(shi)利用(yong)了電(dian)(dian)磁(ci)效(xiao)應來控(kong)制(zhi)機械觸點(dian)達到(dao)通斷(duan)目的(de)(de),給帶有鐵(tie)芯線(xian)圈(quan)通電(dian)(dian)-線(xian)圈(quan)電(dian)(dian)流產(chan)生磁(ci)場-磁(ci)場吸(xi)附銜(xian)鐵(tie)動作通斷(duan)觸點(dian),整個(ge)(ge)過(guo)程(cheng)是(shi)“小電(dian)(dian)流-磁(ci)-機械-大(da)(da)電(dian)(dian)流”這樣一(yi)個(ge)(ge)過(guo)程(cheng)。
只要在線(xian)圈(quan)(quan)兩端加(jia)上一定的(de)(de)(de)電(dian)壓,線(xian)圈(quan)(quan)中(zhong)就(jiu)會(hui)(hui)流過(guo)一定的(de)(de)(de)電(dian)流,從而產生(sheng)電(dian)磁效(xiao)應,銜鐵就(jiu)會(hui)(hui)在電(dian)磁力(li)吸引的(de)(de)(de)作用下(xia)克服返回彈簧的(de)(de)(de)拉力(li)吸向鐵芯,從而帶動銜鐵的(de)(de)(de)動觸(chu)點(dian)與靜(jing)觸(chu)點(dian)(常(chang)開觸(chu)點(dian))吸合。當線(xian)圈(quan)(quan)斷電(dian)后,電(dian)磁的(de)(de)(de)吸力(li)也隨之消失,銜鐵就(jiu)會(hui)(hui)在彈簧的(de)(de)(de)反作用力(li)返回原(yuan)來(lai)的(de)(de)(de)位置(zhi),使(shi)動觸(chu)點(dian)與原(yuan)來(lai)的(de)(de)(de)靜(jing)觸(chu)點(dian)(常(chang)閉(bi)觸(chu)點(dian))釋放。這樣吸合、釋放,從而達到了在電(dian)路(lu)中(zhong)的(de)(de)(de)導通、切斷的(de)(de)(de)目的(de)(de)(de)。對于繼電(dian)器的(de)(de)(de)“常開(kai)、常閉(bi)”觸(chu)點(dian)(dian),可以這樣(yang)來區分:繼電器線圈未通(tong)電時(shi)處(chu)于斷開(kai)狀態(tai)的靜觸(chu)點(dian)(dian),稱為“常開(kai)觸(chu)點(dian)(dian)”;處(chu)于接通(tong)狀態(tai)的靜觸(chu)點(dian)(dian)稱為“常閉(bi)觸(chu)點(dian)(dian)”。
三、電磁繼電器的應用
防訊報(bao)警器:水位上(shang)漲(zhang)超過警戒線時,浮子上(shang)升,使控制電(dian)(dian)路(lu)接通(tong),電(dian)(dian)磁(ci)鐵(tie)吸下銜鐵(tie),于是報(bao)警器指示(shi)燈電(dian)(dian)路(lu)接通(tong),燈亮(liang)報(bao)警。
溫度(du)自動報(bao)警器:當(dang)溫度(du)升高到一定(ding)值(zhi)時(shi),水銀溫度(du)計(ji)中水銀面上升到金屬絲(si)處,水銀是導體(ti)。因此將電(dian)(dian)磁鐵電(dian)(dian)路接通,電(dian)(dian)磁鐵吸引彈(dan)簧(huang)片(pian),使電(dian)(dian)鈴(ling)(ling)電(dian)(dian)路閉合,電(dian)(dian)鈴(ling)(ling)響報(bao)警,當(dang)溫度(du)下(xia)降后,水銀面離開金屬絲(si),電(dian)(dian)磁鐵電(dian)(dian)路斷開,彈(dan)簧(huang)片(pian)回原狀(zhuang),電(dian)(dian)鈴(ling)(ling)電(dian)(dian)路斷開,電(dian)(dian)鈴(ling)(ling)不再發(fa)聲。