課程概述：
 The class will be divided into four parts.
 They are (1) diodes, (2) field effect transistors, (3) bipolar junction transistors (BJTs), and (4) operational amplifiers (op-amp’s).
 Different from the usual electronics curriculum which is mainly focused on low voltage applications, power applications to electromechanical systems like motors and electric vehicles will be the focus of this class.
目標：
 Provide knowledge of selective topics in electrical engineering for electromechanical applications.
 After the class, we should be able to understand
 I-V characteristics of diodes, transistors and op-amp’s
 Electronics applications to power electromechanical systems