可(ke)控(kong)硅(Silicon Controlled Rectifier) 簡(jian)稱(cheng)SCR，是(shi)一種大(da)功率(lv)電(dian)器元(yuan)件(jian)(jian)(jian)，也稱(cheng)晶閘管。它具有(you)體積小、效率(lv)高、壽命長等優點。在(zai)自動(dong)(dong)控(kong)制(zhi)系(xi)統(tong)中，可(ke)作為大(da)功率(lv)驅動(dong)(dong)器件(jian)(jian)(jian)，實(shi)現用小功率(lv)控(kong)件(jian)(jian)(jian)控(kong)制(zhi)大(da)功率(lv)設備。它在(zai)交直流電(dian)機(ji)調速系(xi)統(tong)、調功系(xi)統(tong)及隨(sui)動(dong)(dong)系(xi)統(tong)中得到了(le)廣泛的(de)應用。單向可(ke)控(kong)硅只(zhi)能(neng)單向導通(tong)。