听力原文： Presenter: Welcome to this presentation on our online course, An Introduction to Electronics, which runs over 10 weeks and starts on 8th May. Let me just say at the beginning that if you cannot make this date, please send me an email about the next course and I will send you a list of future dates. My email is the front of your brochures.Now, let me tell you something about the course. Based upon our popular two-day Overview of Electronics course, this new online course will introduce you to the basic ideas behind electronic circuits. The course will consist of ten units each of which will involves around five hours of study. The course is designed to act both as an introductory course and as a refresher course. After taking the course you should have a good idea of how electronic systems work and how they are made. In particular, the course focuses on the design of a Hi-Fi amplifier. The course is limited to 'analogue electronics' where signals are represented by continuously variable voltages and will not cover 'digital electronics' where signals are represented by discrete numbers.Students should normally have a reasonable proficiency in school Maths and Science. Study to GCSE-level is sufficient for most of the course, though study to A-level will enable a full understanding of the more advanced topics. Students on the course will be supplied with a copy of Terry Fit's 'Fundamentals of Electronics'. This will be used for directed reading, assignments and further study. It also serves as a useful reference source. The student should have PC available and a basic knowledge of Windows in order to use the simulation software from the CD-ROM that comes with this book.Now, who is this course designed for? This course is intended for individuals with little prior knowledge of electrical or electronic engineering who want to get a feeling for the subject and for individuals whose knowledge is 'rusty' or out of date. A previous exposure to basic science and maths at school will be assumed; maximum benefit will accrue to those who have attended higher education in a technical subject or who have experience in a related area. Typical attendees may include those in jobs which bring them into contact with electronics, such as drafts persons, PCB designers, production and assembly personnel and software designers, those working with electronic products, such as managers and sales persons, those coming into electronics from a related field, such as scientists or mathematicians, and those simply curious to find out about this all-pervasive technology.The benefits of this course are that, first, it gives you a quick insight into modem electronics. It also puts emphasis on practical devices and systems. Unlike many other courses, no prior knowledge is assumed, but previous exposure to school-level science and maths is assumed. Fourthly, it can be used as a refresher course. Fifth, there is the benefit of getting hands-on simulations and, finally, all delegates completing the course will receive a University of Oxford Certificate of Completion.The course will be presented by Brian Williams, who started his career working as an electronic engineer for British Aerospace. Brian then became a lecturer and has taught electronics at Oxford University & Jesus College for longer than he cares to admit. He is also an active consultant and researcher. Brian is a dynamic lecturer and particularly enjoys teaching introductory-level courses and interacting with students.Now, finally, let me just quickly go through the course content. Please remember that this course is intended for individuals with limited prior knowledge of electrical or electronic engineering.Unit 1 looks at electronic systems, including an introduction to the idea of signals represented by voltages; wires used to transfer signals and voltage from one pla