Demonstration content: Demonstrate the working principle of a single-phase AC generator; electric-phase DC generator Purpose: This machine is used for the basic structure and working principle of AC and DC generators in the teaching of junior high school physics and elementary school natural knowledge. Structure: This instrument is a permanent magnet, rotatable armature generator, composed of a stator, a rotor, brushes, a base plate and a manual mechanism. Great educational toy, it can cultivate children's interest in physics, more intuitive and easy to understand Good for school teaching tool, learning display, and collectibles, also be a great addition to supplies.