[电] regulation of a constant-potential transformer

dìng wèi biàn yā qì tiáo zhěng lù ㄉㄧㄥˋ ㄨㄟˋ ㄅㄧㄢˋ ㄧㄚ ㄑㄧˋ ㄊㄧㄠˊ ㄓㄥˇ ㄌㄨˋ