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.

摘要介绍自行车上使用的花鼓式发电机的演，所用磁石，即铁氧体或钕铁硼的性能优劣，并进行市场前景展望。