Tiān-kám-khì (Eng-gí: inductor) sī pī-tōng-sèng ê siang bóe tiān-khì goân-kiāⁿ, tong tiān-liû keng-kòe ê sî, thang siu chûn tiān-khì lêng-liōng tī chû-tiûⁿ lāi-bīn.