微動(dòng)開關(guān)上面有個(gè)金屬片 ，壓下去斷開的是 常開還是常閉？反之，金屬片壓下去閉合的是常開還是常閉？
壓下去斷開的是常閉式，壓下去閉合的是常開式。 一般有三只腳的的是轉(zhuǎn)換式，具體用常開常閉看你需要 接線。一般三只腳的都標(biāo)有NC NO COM，NC表示normal close ，也就是常閉 ，NO 表示 normal open，也就是常開，COM表示公共端子，一般需要常閉設(shè)計(jì) 線就接NC COM，常開則接NO COM。一般大一點(diǎn)的開關(guān) 三只腳是上中下 依次是NC NO COM，常閉設(shè)計(jì)連接一三腳即可。小一點(diǎn)開關(guān) 三只腳是平行的 依次也是NC NO COM 接線同理。 一般三只腳的轉(zhuǎn)換型，其壓片（彈簧或者鈹銅簧片）聯(lián)動(dòng)的觸點(diǎn)（銀觸點(diǎn)）的起始位置都停在NC腳上，也就是常閉觸點(diǎn)上。你接一三腳 即是常閉，接二三腳即是常開 。
There is a piece of metal on the micro switch. Is it normally open or closed if you press it down? On the other hand, when the sheet metal is pressed down, is it normally open or normally closed?
Press off is normally closed, press closed is normally open. Generally has three legs is the conversion type, the specific use of normal open and close to see you need wiring. Normally, normally closed design line is connected to NC COM, normally open is connected to NO COM. Generally a little larger switch three legs is the upper middle lower order is NC NO COM, normally closed design connected to a three legs. The three legs of the smaller switch are parallel. The starting position of the contact (silver contact) of the press (spring or beryllium-copper reed) linkage of the general three-legged transition type stops at the NC foot, that is, the normally closed contact. When you have one or three legs, it is normally closed; when you have two or three legs, it is usually open.