I have my students to thank for this book. Regardless of ability， each has had

　　a role to play. The more able students have always helped， through their project work， to develop new ideas and solutions in electronic design. Some have

　　displayed an astonishing instinctive understanding of engineering ideas， and

　　some have been so keen to learn as to make teaching easy and rewarding.

　　There is never enough time to give each individual student the time and help

　　they deserve. So， one has to start writing to make sure that the essential technical information is at least accessible， and hope that students are able to make

　　best use of it.

　　Another spur to writing this book has been the development of the interactive design software which has made the job of learning and teaching electronics that much more enjoyable. The Proteus software used in this book has

　　been developed by a talented team at Labcenter Electronics in the UK， led by

　　John Jameson and Iain Cliffe. They have a world beating product， and I wanted

　　to make a small contribution to encouraging students and engineers to use it

　　It allows us to bring electronic circuits to life on the computer screen instantly.

　　It has always been a problem in electronics that you cannot see a circuit

　　working in the same way that a mechanical engineer can see a steam engin

　　pumping up and down. Sure， we can see the screen flickering on a television，

　　or an electric motor spinning， but you cannot see electrons or volts. As a result， it has always been that much more difficult to teach electronics. Proteus

　　is a big step towards bringing electronics alive， as such it helps us to participate more effectively in the communications and information revolution that is

　　all around us.