[电] copper sulfide rectifier, copper-sulfied rectifier
liú huà tóng zhěng liú qì ㄌㄧㄡˊ ㄏㄨㄚˋ ㄊㄨㄥˊ ㄓㄥˇ ㄌㄧㄡˊ ㄑㄧˋ