微型減速電機的(de)(de)(de)電(dian)機固定有(you)環狀永磁(ci)體，電(dian)流通過轉(zhuan)子(zi)上的(de)(de)(de)線(xian)圈產(chan)(chan)生(sheng)安(an)培力，當轉(zhuan)子(zi)上的(de)(de)(de)線(xian)圈與磁(ci)場平(ping)行時，再繼續轉(zhuan)受到的(de)(de)(de)磁(ci)場方(fang)向(xiang)將(jiang)改變(bian)，因此此時轉(zhuan)子(zi)末端的(de)(de)(de)電(dian)刷跟轉(zhuan)換片交替接觸，從而線(xian)圈上的(de)(de)(de)電(dian)流方(fang)向(xiang)也改變(bian)，產(chan)(chan)生(sheng)的(de)(de)(de)洛倫茲力方(fang)向(xiang)不變(bian)，所以電(dian)機能保(bao)持(chi)一個方(fang)向(xiang)轉(zhuan)動。下面(mian)兆威就給(gei)大(da)家介(jie)紹一下如(ru)何區分直流電(dian)機是有(you)刷還是無刷：

　1.小(xiao)型(xing)減速(su)電(dian)機(ji)看外觀，通常無刷(shua)直(zhi)流電(dian)機(ji)扁(bian)平，有刷(shua)直(zhi)流電(dian)機(ji)長度(du)大(da)于直(zhi)徑。

　2.查結構，拆(chai)開電機，看見碳刷是(shi)(shi)有(you)刷直(zhi)流(liu)電機，否則是(shi)(shi)無刷直(zhi)流(liu)電機。

  3.對好(hao)的(de)直(zhi)流電(dian)(dian)(dian)(dian)機(ji)可用(yong)(yong)發電(dian)(dian)(dian)(dian)法測(ce)試。用(yong)(yong)指(zhi)針式(shi)萬(wan)用(yong)(yong)表接在直(zhi)流電(dian)(dian)(dian)(dian)機(ji)電(dian)(dian)(dian)(dian)源(yuan)線上(shang)，萬(wan)用(yong)(yong)表調(diao)節到低壓電(dian)(dian)(dian)(dian)壓檔，用(yong)(yong)手慢慢轉動(dong)電(dian)(dian)(dian)(dian)機(ji)軸，如果指(zhi)針不動(dong)可以加快轉動(dong)，指(zhi)針偏轉的(de)是有刷直(zhi)流電(dian)(dian)(dian)(dian)機(ji)，否則是無刷直(zhi)流減速電(dian)(dian)(dian)(dian)機(ji)。