关键词: 楞次定律, 电磁感应摆, 光控开关

Abstract: Abstract：An interesting electromagnetic induction pendulum is introduced, here the driving force is the elec-tromagnetic induction magnetic one. It is controlled by the electronic switching circuit when the driving force is emerged. During a full oscillation cycle the pendulum is driven four times by the driving force, so the pendulum can swing all the time, which seems like ＂moving permanent＂. We also describe in detail about how it works and how to make it.

Key words: Lenz law, electromagnetic induction pendulum, light control switch