"通信专业英语：交流电、直流电和电信号词汇详解.ppt"

Unit Ⅰ Basic Knowledge of Electronics Lesson 3 AC, DC and Electrical Signals In this lesson, we will be learning about the differences between alternating current (AC) and direct current (DC), as well as electrical signals. These are fundamental concepts in electronics and are crucial for understanding how communication systems work. AC, or alternating current, is a type of electrical current that constantly changes direction. It is commonly used in household wiring and power transmission. DC, or direct current, is a constant flow of electrons in one direction. It is often used in electronic devices such as phones and computers. The translation of the text and the new words introduced in this lesson provide a solid foundation for understanding the key concepts of AC, DC, and electrical signals. The new words include terms such as amplitude, microsecond, and oscilloscope, which are essential for grasping the technical aspects of electronics. Phrases and expressions like positive, label, measure, device, and frequency are also covered in this lesson, adding to the vocabulary needed to discuss and analyze electronic systems. It is important to familiarize oneself with these terms in order to effectively communicate and troubleshoot issues in the field of electronics. Overall, this lesson serves as a comprehensive introduction to the basics of electronics and lays the groundwork for further study in communication systems. By mastering the concepts of AC, DC, and electrical signals, students will be better equipped to excel in their future coursework and careers in the field of communications. In conclusion, communication professionals must have a strong understanding of AC, DC, and electrical signals in order to design and maintain effective communication systems. This lesson provides a solid foundation in these key concepts, equipping students with the knowledge and skills needed to succeed in the field of electronics and telecommunications.