Interview: David A Bell

David A Bell is a Canadian professor of Electronics. He has written various textbooks which are widely prescribed to students of engineering. We interviewed him over email for the Dept of Instrumentation Technology's fest TransIT 2009. This was featured in the fest newsletter. The entire interview is presented here with minimal editing. His website is at www.Davidabell.com

1)Could you describe your engineering career from the start? How was the transition from being a student to teaching to writing texts that now serve as reference?

My first employment as an engineer was with the Shortt & Harlands in Belfast Northern Ireland where I was born and grew up. My transition from student to engineer was not difficult, in fact in some ways it was almost like a continuation of college. I shared an office with several other young recently-hired engineers, and nearby offices were occupied by older, experienced, engineers who were our supervisors. Our offices were also on the periphery of workshops staffed by technicians who constructed prototypes of our designs. The work atmosphere was relaxed and friendly.

After some years with Short and Harland I moved to Canada and worked for companies in Halifax and Ottawa. In my first engineering job we were still designing vacuum tube circuitry, because the available transistors were very unreliable. Thermal runaway was a major concern. However, reliable transistors soon became available, and then everything switched over to transistor circuits. Bipolar junction transistors (BJTs) had been introduced only in the last year of my studies, so I had to do a lot of reading to teach myself transistor circuit design. When field effect transistors (FETs) became available, more study was necessary to learn FET circuit design. Then, of course, integrated circuits became an ongoing area of study. I also attended many design courses sponsored by my employers. Obviously, continuous learning is part of every engineers experience.

As well as circuit and system design, much of my work as an engineer involved technical writing; specifications, design reports, test procedures etc. I also did some travelling to companies who were contracted to my employer, and in this case I reported on the quality and progress of a particular project.

During the first year of my teaching carreer I found myself working harder than at any time previous! This was because (in company with other new college professors) I was reviewing the subjects I had to teach, preparing lectures and tests, and writing laboratory investigation procedures. Ontario had just started twenty new Colleges of Applied Arts and Technology, and the resources we needed were not available.

2)How is teaching Electronics and Instrumentation now different from how you were taught the same subjects?

As mentioned above, the material studied has changed considerably. However, the learning process is still fairly similar; student attend lectures, study text books, perform laboratory investigations, solve problems, write tests. Practical hands-on experience testing circuits in a laboratory is very important. I have heard of colleges where students are only allowed to witness laboratory demonstrations, and I see this as quite unsatisfactory. The availablity of calculators and computer circuit simulation is a major improvement on my own student experience.

3)What is the usual process of writing a textbook?

With few exceptions, I was unsatisified with the available text books when I commenced teaching electronics. So, I always prepared student hand-out sheets explaining theory and showing problem solutions. The handouts became a major resource for my text book writing. I cannot say how long my first book took to write, because of the process of interesting a publisher in the project. The procedure was: submit an outline and six chapters to a publisher, rewrite the six chapters to incorporate an editor's suggestions, receive a rejection, and then start over again with another publisher. When I did get my first book published, and then signed a contract for a second book, the second book was written, edited, and published within a year. That was because I had all of the material for the second book in the form of student hand-outs.

I try to write exactly the way I would lecture. The material has to be clearly understandable to students. The content has to cover the items listed in most course outlines, and in each new edition I have added new material and deleted material that has become outdated or less important. Updating a book usually takes me a year of something less than full-time work in my present semi-retired situation.

4) Do you agree with the methods generally adapted to teach engineering? (in the context of Instrumentation and Electronics). If not, what are the methods you would recommend?

I tend to agree with the typical engineering teaching methods.

5) Are there any experiences that you've had as a part of your engineering career/teaching that have influenced your ideas on the field?

The following is a quote from the preface to one of my books:

I am convinced that an understanding of device and circuit operation is most easily achieved by learning how to design circuit. Circuit design is usually quite simple; much simpler than some methods of circuit analysis.

6)Everybody would love to know what you do in your free time. What are your interests apart from technology and teaching?

When my children were young we used to camp and go on canoe trips during summer, and ski in winter. I am long past skiing right now, and as I get older the Canadian winter seem longer. I have a sail boat that I sail on Lake Huron during summer. My wife is a retired elementary school teacher, and our children have all grown up and left home. We are recreational ballroom dancers, take dance lessons once a week, help out with beginner dance classes, and attend dances at least three times each month. We also like to travel. In May of this year we visited Peru, and next January we plan a trip to Egypt.