加藤, 徹也

KATO, Tetsuya

[SUMMARY]An electromagnet changes it’s the strength and the directions of magnetic fields depending on the amount of electric current and direction of current. This property of electromagnet is learned in the fifth grade of elementary school. Junior high school 2nd-grade students learn the contents that focus on the relationship between current and magnetic field. Recently, magnetic floating toys are being marketed, and the strange float controlled by electromagnetic forces has become common. Such phenomenon impresses the existence of non-contact force and attracts children's interest so as to appear in science textbooks for junior high school. However, the structure of the commercial products is covered with a black box, so that it is difficult to recall specific learning contents. Therefore, the present author showed the way of making magnetic floating device from scratch and analyzed the mechanism of its levitation in order to develop science teaching materials. A simple microcomputer (Arduino) with a magnetic field sensor was used to control the electromagnet current. Furthermore, the magnetic field distribution during floating was analyzed by use of the finite element method software.