A.常開(kāi)按鈕先閉合 B.常開(kāi)按鈕先斷開(kāi) C.常閉按鈕后閉合 D.常閉按鈕后斷開(kāi)
A.電源端應(yīng)接在刀開(kāi)關(guān)上方 B.電源端應(yīng)接在刀開(kāi)關(guān)下方 C.負(fù)載端應(yīng)接在刀開(kāi)關(guān)下方 D.負(fù)載端應(yīng)接在接刀開(kāi)關(guān)上方
A.增強(qiáng)磁感應(yīng)強(qiáng)度 B.減小鐵心的振動(dòng) C.減小鐵心噪音 D.增大電磁吸力