Demonstration of the structure of DC motors and AC and DC generators. It is used for working principle. It is a multifunctional combined demonstration point machine. Principle and structure: This instrument is designed based on the principle that the energized coil rotates in the magnetic field and the closed coil rotates in the magnetic field to generate current. This instrument is composed of "U"-shaped bracket, armature, magnet, collector ring, brush, base and upper cover. Enhance children's hands-on ability and fun. Size: 19.5*27.5*20.5cm