意聯電氣電纜識別儀工作原理和技術指標
標簽: 電纜識別儀
意聯電氣電纜識別儀工作原理:
為了可靠準確地識別電纜,需要給被識別電纜加一特殊的信號,該信號要被專用接收機接收,利用這一特性便能識別出要找的電纜。
接(jie)收機的任務是(shi)探測流(liu)過電(dian)纜電(dian)流(liu)方向(xiang)以及它的大小。為(wei)(wei)達到這一目的,電(dian)流(liu)傳感(gan)(gan)器(qi)被用作(zuo)傳感(gan)(gan)器(qi),它帶有一放大器(qi)并串聯在電(dian)路中(zhong),傳感(gan)(gan)器(qi)鉗住(zhu)被測電(dian)纜,電(dian)流(liu)流(liu)過電(dian)纜產(chan)生的磁場在傳感(gan)(gan)器(qi)的線(xian)圈中(zhong)感(gan)(gan)應出電(dian)壓,該電(dian)壓極性由(you)電(dian)流(liu)方向(xiang)和傳感(gan)(gan)器(qi)線(xian)圈的方向(xiang)決定。為(wei)(wei)了得到明顯有電(dian)流(liu)方向(xiang)的電(dian)壓極性,對一束(shu)電(dian)纜中(zhong)所有電(dian)纜進行測試都(dou)采取相同正(zheng)確的方向(xiang)。
傳感(gan)器線圈中感(gan)應的(de)電(dian)(dian)壓在表頭中顯示(shi)出來,如果傳感(gan)器按上(shang)述方式(shi)連(lian)接,指針(zhen)(zhen)擺(bai)動方向(xiang)(xiang)可顯示(shi)電(dian)(dian)流(liu)(liu)方向(xiang)(xiang),即只有(you)電(dian)(dian)流(liu)(liu)流(liu)(liu)出的(de)這根電(dian)(dian)纜(lan)指針(zhen)(zhen)向(xiang)(xiang)一邊偏,這根就是要(yao)找的(de)電(dian)(dian)纜(lan)。所有(you)其它電(dian)(dian)纜(lan)只流(liu)(liu)過返回(hui)電(dian)(dian)流(liu)(liu),指針(zhen)(zhen)向(xiang)(xiang)另(ling)一邊偏、或無脈(mo)動電(dian)(dian)流(liu)(liu),指針(zhen)(zhen)不偏轉。接收機上(shang)的(de)放大(da)調節器可調整信號(hao)強度。
電(dian)(dian)(dian)纜識(shi)別儀發生器將周期性(xing)(xing)的(de)(de)(de)(de)單極性(xing)(xing)電(dian)(dian)(dian)壓(ya)脈沖饋入(ru)要識(shi)別的(de)(de)(de)(de)電(dian)(dian)(dian)纜中(zhong)(zhong),該電(dian)(dian)(dian)纜需要在遠端接地,以保證(zheng)有(you)足夠(gou)大(da)的(de)(de)(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)流(liu)(liu)(liu)(liu)過電(dian)(dian)(dian)纜。該系統要設(she)計(ji)成返回(hui)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)不要從同一(yi)(yi)電(dian)(dian)(dian)纜中(zhong)(zhong)返回(hui),能做(zuo)到(dao)這一(yi)(yi)點,饋入(ru)電(dian)(dian)(dian)纜中(zhong)(zhong)的(de)(de)(de)(de)脈沖電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)的(de)(de)(de)(de)方(fang)向(xiang)可做(zuo)為一(yi)(yi)明顯的(de)(de)(de)(de)識(shi)別標準,流(liu)(liu)(liu)(liu)出去的(de)(de)(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)僅從這一(yi)(yi)根(gen)電(dian)(dian)(dian)纜通(tong)過,所(suo)有(you)其(qi)它鄰(lin)近電(dian)(dian)(dian)纜中(zhong)(zhong)流(liu)(liu)(liu)(liu)過的(de)(de)(de)(de)都是返回(hui)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu),但它們的(de)(de)(de)(de)極性(xing)(xing)相反。除了電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)方(fang)向(xiang)這一(yi)(yi)實際差異外,電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)幅度也是一(yi)(yi)識(shi)別特(te)征(zheng),流(liu)(liu)(liu)(liu)出去的(de)(de)(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)僅通(tong)過一(yi)(yi)根(gen)電(dian)(dian)(dian)纜、而返回(hui)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)可通(tong)過幾根(gen)電(dian)(dian)(dian)纜、這意(yi)味著流(liu)(liu)(liu)(liu)出去的(de)(de)(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)比流(liu)(liu)(liu)(liu)過其(qi)它電(dian)(dian)(dian)纜的(de)(de)(de)(de)返回(hui)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)大(da)。
a、 儀器供電:電纜識別儀主機由交流220V供電,接收機由一節9V電池供電。
b、 卡鉗:卡鉗是一電流交換器,鉗口內口尺寸為120mm,在卡鉗內感應出電壓,電壓幅度由電流強度決定,其極性由電流方向決定。