1. Reference: The open course Electrician and Electronics (Volume II) of Chongqing University, one of which is an overview of relay contactor control system. This course is taught by famous professors Hou Shiying, Tao Sun and Zhou Jing from School of Electrical Engineering, Chongqing University.
2. The content is simple: the principle of relay contactor control system is relatively simple, it can be operated in practice, and the classroom atmosphere is more active.