Foreword
Of the four main items of electric bicycles, chargers and controllers are sophisticated electronic products. The book has been prepared by the author because of the conditions and special circumstances under which electric bicycles are used, which often cause a variety of malfunctions, while the maintenance of electronic products is difficult and requires specialized electronic knowledge。

From a concise, practical and learning-friendly perspective, the book presents in a shallow, in-depth and systematic way electric bicycle chargers, commonly used tools and instruments for controller overhaul, detection and bad judgement methods for electromechanical devices, chargers, the structure of controllers, circuits and methods of overhauling, so that readers can see at first sight that they are learning to achieve quick learning。
In addition, the book lists a great deal of trouble-shooting experiences and techniques, and readers can learn through reading to achieve one-on-one, incisive, adjunct effects。

Information on commonly used integrated circuits and on chargers and controller circuit charts are also included in the final book for access by maintenance personnel。
The technical information and illustrations of this book are provided by the green union training school for the repair of electric vehicles in loyang city, henan province. The symbols of the parts of the book and their labels are consistent with the original circuit map and are not standardized. In addition, liu weijie, malixia, liu yuen ying and malije participated in the preparation of the book and are also grateful。
The book was prepared by the author on the basis of years of experience in the teaching and maintenance of electric bicycles, and is more readable and operational. The authors can be contacted by a wide audience for technical training and maintenance equipment, tel. 0379-65172171,15824994061. Also available at www. Ydz8. Cn。

Owing to the limited level of authorship, combined with the shortness of time, there may be shortcomings and omissions in the book, which can be corrected when reprinted by a wide audience and peer criticism。
Editor




