transformer
noun [ C ] physics, electronics uk/trænsˈfɔː.mər/ us/trænsˈfɔːr.mɚ/
变压器
a device that changes the voltage or other characteristic of electrical energy as it moves from one circuit to another
Wire the fan and a 12-volt transformer to the light switch. 用电线把风扇和12伏变压器连到电灯开关上。