Evolving process of hub dynamo which used in bicycle is presented. The performance of magnetite viz. ferrimagnetism or NdFeB is analyzed. The prospect of marketing is viewed.

摘了自车上使用的花鼓式发电机的演变过程，析了所用磁石，即铁氧体或钕铁硼的性能优劣，了市场前景展望。