它是(shi)將電(dian)(dian)(dian)信(xin)(xin)(xin)號(hao)轉(zhuan)換(huan)成氣(qi)(qi)(qi)(qi)(qi)(qi)信(xin)(xin)(xin)號(hao)輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)的(de)裝(zhuang)置，與氣(qi)(qi)(qi)(qi)(qi)(qi)電(dian)(dian)(dian)轉(zhuan)換(huan)器作(zuo)用剛好相反。按(an)輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)氣(qi)(qi)(qi)(qi)(qi)(qi)信(xin)(xin)(xin)號(hao)的(de)壓力(li)也分為高壓（＞0.1MPa）、中壓（0.01～0.1MPa）和(he)低壓（<0.01MPa）三(san)種(zhong)，常用的(de)電(dian)(dian)(dian)磁閥即是(shi)一種(zhong)高壓電(dian)(dian)(dian)氣(qi)(qi)(qi)(qi)(qi)(qi)轉(zhuan)換(huan)器。圖示為噴(pen)嘴擋板式(shi)電(dian)(dian)(dian)氣(qi)(qi)(qi)(qi)(qi)(qi)轉(zhuan)換(huan)器結構圖。通電(dian)(dian)(dian)時(shi)線圈3產生磁場(chang)將銜(xian)鐵吸下(xia)，使(shi)檔板5堵住噴(pen)嘴6、氣(qi)(qi)(qi)(qi)(qi)(qi)源(yuan)(yuan)輸(shu)(shu)(shu)(shu)(shu)(shu)入的(de)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)經(jing)過節流(liu)孔 7后(hou)從輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)口輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)，即有輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)氣(qi)(qi)(qi)(qi)(qi)(qi)信(xin)(xin)(xin)號(hao)。斷電(dian)(dian)(dian)時(shi)磁場(chang)消失，銜(xian)鐵在彈性(xing)支承2的(de)作(zuo)用下(xia)使(shi)擋板5離開噴(pen)嘴6，氣(qi)(qi)(qi)(qi)(qi)(qi)源(yuan)(yuan)輸(shu)(shu)(shu)(shu)(shu)(shu)入的(de)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)經(jing)節流(liu)孔7后(hou)從噴(pen)嘴6噴(pen)出(chu)(chu)，輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)口則無氣(qi)(qi)(qi)(qi)(qi)(qi)信(xin)(xin)(xin)號(hao)輸(shu)(shu)(shu)(shu)(shu)(shu)出(chu)(chu)。這種(zhong)電(dian)(dian)(dian)氣(qi)(qi)(qi)(qi)(qi)(qi)轉(zhuan)換(huan)器一般(ban)為直流(liu)電(dian)(dian)(dian)源(yuan)(yuan)6～12V，電(dian)(dian)(dian)流(liu)0.1～0.14A，氣(qi)(qi)(qi)(qi)(qi)(qi)源(yuan)(yuan)壓力(li)＜0.01MPa，屬低壓電(dian)(dian)(dian)氣(qi)(qi)(qi)(qi)(qi)(qi)轉(zhuan)換(huan)器。
它是把氣信(xin)(xin)(xin)號(hao)轉(zhuan)換(huan)成電(dian)(dian)信(xin)(xin)(xin)號(hao)的裝置，即利用輸(shu)入氣信(xin)(xin)(xin)號(hao)的變化引起可動部件（如膜片、頂桿(gan)等(deng)）的位(wei)移來接通(tong)或斷開電(dian)(dian)路(lu)，以輸(shu)出電(dian)(dian)信(xin)(xin)(xin)號(hao)。氣電(dian)(dian)轉(zhuan)換(huan)器(qi)(qi)按輸(shu)入氣信(xin)(xin)(xin)號(hao)壓(ya)力的大小分為高壓(ya)（＞0.1MPa）、中(zhong)壓(ya)（0.01～0.1MPa）和低(di)壓(ya)（＜0.01MPa）三種。高壓(ya)氣電(dian)(dian)轉(zhuan)換(huan)器(qi)(qi)又稱之(zhi)為壓力(li)繼電(dian)器。
左圖所示為低壓(ya)(ya)氣(qi)(qi)(qi)電(dian)(dian)轉換(huan)器，硬芯(xin)3和(he)焊(han)(han)片1是兩(liang)個觸(chu)點(dian)，無氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)輸(shu)(shu)入(ru)(ru)時是斷(duan)(duan)開(kai)(kai)的(de)。有一(yi)定壓(ya)(ya)力(li)氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)輸(shu)(shu)入(ru)(ru)時，膜(mo)片2向上運動(dong)帶動(dong)硬芯(xin)3和(he)限位(wei)(wei)螺釘11接(jie)觸(chu)、與焊(han)(han)片1接(jie)通，發出(chu)電(dian)(dian)信(xin)號(hao)(hao)(hao)；氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)消失(shi)時，膜(mo)片帶動(dong)硬芯(xin)復位(wei)(wei)，觸(chu)點(dian)斷(duan)(duan)開(kai)(kai)，電(dian)(dian)信(xin)號(hao)(hao)(hao)消失(shi)。調節螺釘11可以(yi)調整(zheng)接(jie)受(shou)(shou)氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)壓(ya)(ya)力(li)的(de)大小。右圖所示為壓(ya)(ya)力(li)繼電(dian)(dian)器的(de)工作(zuo)原理固(gu)，輸(shu)(shu)入(ru)(ru)氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)使膜(mo)片4受(shou)(shou)壓(ya)(ya)變形去推動(dong)頂(ding)桿(gan)(gan)3啟動(dong)微動(dong)開(kai)(kai)關(guan)1，輸(shu)(shu)出(chu)電(dian)(dian)信(xin)號(hao)(hao)(hao)。輸(shu)(shu)入(ru)(ru)氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)消失(shi)，膜(mo)片4復位(wei)(wei)，頂(ding)桿(gan)(gan)在彈簧作(zuo)用下(xia)下(xia)移，脫(tuo)離微動(dong)開(kai)(kai)關(guan)。調節螺母2可以(yi)改變接(jie)受(shou)(shou)氣(qi)(qi)(qi)信(xin)號(hao)(hao)(hao)的(de)壓(ya)(ya)力(li)值。其結構(gou)簡單，制造容易，應(ying)用廣泛。
使用氣電轉換器時(shi)，應避(bi)免(mian)將其安(an)裝在振動(dong)較大的地(di)方。并不應傾斜和倒(dao)置，以免(mian)產生(sheng)誤動(dong)作，造成事故(gu)。
