微動(dong)(dong)(dong)開(kai)(kai)關(guan)是(shi)一(yi)(yi)(yi)種施壓促動(dong)(dong)(dong)的(de)(de)快速開(kai)(kai)關(guan)，又叫靈(ling)敏開(kai)(kai)關(guan)。一(yi)(yi)(yi)種行程很小的(de)(de)、瞬時(shi)動(dong)(dong)(dong)作(zuo)的(de)(de)主(zhu)令電(dian)器. 微動(dong)(dong)(dong)開(kai)(kai)關(guan)是(shi)小型(xing)的(de)(de)接(jie)觸開(kai)(kai)關(guan)，手輕輕碰一(yi)(yi)(yi)下(xia)(xia)(xia)就接(jie)通，工廠里常用作(zuo)大開(kai)(kai)關(guan)內(nei)部的(de)(de)短路、過流保護.  當(dang)外界(jie)機械力(li)作(zuo)用于操作(zuo)鈕(niu)時(shi)，操作(zuo)鈕(niu)便向下(xia)(xia)(xia)運(yun)動(dong)(dong)(dong)，通過拉鉤將彈簧(huang)拉伸。當(dang)彈簧(huang)拉到一(yi)(yi)(yi)定長度(du)后(hou)，動(dong)(dong)(dong)簧(huang)片(pian)迅速向下(xia)(xia)(xia)運(yun)動(dong)(dong)(dong)，動(dong)(dong)(dong)簧(huang)片(pian)右端的(de)(de)觸頭(tou)轉(zhuan)向與(yu)下(xia)(xia)(xia)面的(de)(de)常開(kai)(kai)觸頭(tou)接(jie)觸，從而實現電(dian)路的(de)(de)轉(zhuan)換。如果去除外力(li)，在彈簧(huang)恢復力(li)的(de)(de)作(zuo)用下(xia)(xia)(xia)，觸頭(tou)又瞬時(shi)地(di)進(jin)行轉(zhuan)換。再加裝一(yi)(yi)(yi)些滾輪或壓塊，則可派(pai)生出其他結構型(xing)式的(de)(de)微動(dong)(dong)(dong)開(kai)(kai)關(guan)，可適應不(bu)同用途。廣泛應用在鼠標，家用電(dian)器，工業機械，摩托(tuo)車等地(di)方，開(kai)(kai)關(guan)雖小，但起(qi)著不(bu)可替代的(de)(de)作(zuo)用。  
    微(wei)(wei)動(dong)(dong)(dong)(dong)開(kai)關(guan)(guan)的工作(zuo)原理是：外機(ji)(ji)械力通(tong)過傳(chuan)(chuan)(chuan)動(dong)(dong)(dong)(dong)元件（按(an)(an)銷、按(an)(an)鈕(niu)(niu)、杠(gang)桿、滾(gun)輪(lun)(lun)等）將(jiang)力作(zuo)用于動(dong)(dong)(dong)(dong)作(zuo)簧片(pian)上(shang)，并將(jiang)能量積聚到(dao)臨界(jie)點后，產生(sheng)瞬時動(dong)(dong)(dong)(dong)作(zuo)，使動(dong)(dong)(dong)(dong)作(zuo)簧片(pian)末端的動(dong)(dong)(dong)(dong)觸(chu)(chu)點與(yu)定(ding)觸(chu)(chu)點快速接通(tong)或斷(duan)開(kai)。當傳(chuan)(chuan)(chuan)動(dong)(dong)(dong)(dong)元件上(shang)的作(zuo)用力移去后，動(dong)(dong)(dong)(dong)作(zuo)簧片(pian)產生(sheng)反向動(dong)(dong)(dong)(dong)作(zuo)力，當傳(chuan)(chuan)(chuan)動(dong)(dong)(dong)(dong)元件反向行程達到(dao)簧片(pian)的動(dong)(dong)(dong)(dong)作(zuo)臨界(jie)點后，瞬時完成反向動(dong)(dong)(dong)(dong)作(zuo)。微(wei)(wei)動(dong)(dong)(dong)(dong)開(kai)關(guan)(guan)的觸(chu)(chu)點間距小(xiao)、動(dong)(dong)(dong)(dong)作(zuo)行程短(duan)、按(an)(an)動(dong)(dong)(dong)(dong)力小(xiao)、通(tong)斷(duan)迅速。其動(dong)(dong)(dong)(dong)觸(chu)(chu)點的動(dong)(dong)(dong)(dong)作(zuo)速度與(yu)傳(chuan)(chuan)(chuan)動(dong)(dong)(dong)(dong)元件動(dong)(dong)(dong)(dong)作(zuo)速度無關(guan)(guan)。微(wei)(wei)動(dong)(dong)(dong)(dong)開(kai)關(guan)(guan)以(yi)按(an)(an)銷式(shi)(shi)(shi)為(wei)基本型，可派(pai)生(sheng)按(an)(an)鈕(niu)(niu)短(duan)行程式(shi)(shi)(shi)、按(an)(an)鈕(niu)(niu)大(da)行程式(shi)(shi)(shi)、按(an)(an)鈕(niu)(niu)特(te)大(da)行程式(shi)(shi)(shi)、滾(gun)輪(lun)(lun)按(an)(an)鈕(niu)(niu)式(shi)(shi)(shi)、簧片(pian)滾(gun)輪(lun)(lun)式(shi)(shi)(shi)、杠(gang)桿滾(gun)輪(lun)(lun)式(shi)(shi)(shi)、短(duan)動(dong)(dong)(dong)(dong)臂(bei)式(shi)(shi)(shi)、長(chang)動(dong)(dong)(dong)(dong)臂(bei)式(shi)(shi)(shi)等等。微(wei)(wei)動(dong)(dong)(dong)(dong)開(kai)關(guan)(guan)在電(dian)(dian)子設備(bei)及(ji)其他設備(bei)中(zhong)用于需頻繁換接電(dian)(dian)路(lu)的自動(dong)(dong)(dong)(dong)控制及(ji)安全(quan)保護(hu)等裝置中(zhong)。微(wei)(wei)動(dong)(dong)(dong)(dong)開(kai)關(guan)(guan)分(fen)(fen)為(wei)大(da)型、中(zhong)型、小(xiao)型，按(an)(an)不同的需要(yao)分(fen)(fen)有(you)可以(yi)有(you)防水(shui)型（放在液體環境中(zhong)使用）和普通(tong)型，開(kai)關(guan)(guan)連接兩(liang)個(ge)線路(lu)，為(wei)電(dian)(dian)器(qi)、機(ji)(ji)器(qi)等提供通(tong)斷(duan)電(dian)(dian)控制。 
    而對微(wei)動(dong)開關的控(kong)制(zhi)，又是利用控(kong)制(zhi)節氣門(men)開度之油門(men)拉(la)(la)線(xian)凸輪(lun)來(lai)實現(xian)的。微(wei)動(dong)開關安裝在拉(la)(la)線(xian)凸輪(lun)合適(shi)位(wei)置上，油門(men)拉(la)(la)線(xian)凸輪(lun)回位(wei)時(shi)，頂住微(wei)動(dong)開關臂，斷開繼電(dian)器(qi)電(dian)磁線(xian)圈電(dian)源，繼電(dian)器(qi)斷開