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The STEM of all Evil, Part 2

If I ever started a polytechnic school, I think I’d flip the curriculum on its head. I’ve been doing engineering work for a long time with lots of design work and troubleshooting sessions and most of the time, our work does not revolve around pencil-and-paper formulas, but around the limitations and defects of our devices. So, let’s teach the students about the strengths and limitations of real components, then add mathematical formulas on top later and only in terms of what is known about real components and real designs.

As an example, Ohms law (isn’t it really Ohm’s relation) is concise and simple, but it presents an unreal view of circuit design. Our discrete resistors are only available in limited values with limited accuracy and limited power handling capacity and that’s without considering nonlinearities and the thermal noise they contribute to a circuit. Voltages only come from a limited number of sources. The resulting currents manifest only in limited ranges and forms. What’s more important, the theory or the practical reality of the devices?

When starting out, we might look at a collection of resistors and discuss why one is bigger than another, why one costs more than another, what the initial accuracy is and what to expect over time. We might let the smoke out of one and discuss what we observed. These characteristics represent practical information almost anyone could grasp. Then, once the intuitive aspects are mastered, we could paste on the mathematics and in this case, as is proper, the math is the slave, not the master. If the math doesn’t describe things we grasp intuitively or things that can be measured or represented in real circuits, then it’s useless and should not be taught.

In our day-to-day work, our problems with capacitors have nothing to do with the theoretical operation. In the lab, the production line or repair facilities, we struggle with aging effects, leakage, voltage derating, interactive resonances, Q and self-heating. Our real world work revolves around understanding and managing the imperfections of these devices. The same can be said for inductors, then we can talk about diodes, transistors, op amps, PWM controllers and all the other folderol of our daily grind.

If you read about Michael Faraday and other pioneers of electronics, this is how they did things. They explored circuit operation and then pasted the mathematics on top to describe what they saw. So, am I nuts to think books like Charles Platt’s Make: Electronics should be part of the first year engineering curriculum?

The way we do things now, students come from engineering school with heads full of theory and it’s up to the mentors at their first jobs to school them in the practical realities of the business. We should turn that backwards around.

What are your thoughts? Set me straight in the comment section.

Ken Coffman is a Field Applications Engineer & Member of the Technical Staff at Fairchild Semiconductor. His postings are his own and don’t necessarily represent the opinions or positions of Fairchild Semiconductor.

7 comments on “The STEM of all Evil, Part 2

  1. eafpres
    May 11, 2015

    Hi Ken–I think you are onto something.  Start them in middle school with some simple voltage/current sources (like batteries) and intentionally let them make resitive circuits and burn up a few.  Then your questions about size, limitations, etc. will lead to some level of intuitive understanding.  Later they can quantify with math.

    It might be a little tougher with caps and inductors.  Perhaps by high school they could understand alternating current and oscillation, and make some simple circuits.  (Let's build the electrical circuit equivalent to a pedulum…).

    You might be able to get high-schoolers through things like Op Amps, counters, ADCs etc. without hitting the books too much.  I'm not sure where the limit of intuition and experimentation might be in this regard.

  2. RobertC61
    May 13, 2015

    Your a brave man Ken!  You run the risk of being dragged out in the dead of night to be ritually castrated for daring to suggest such a thing as doing something practical before the theory has been studied.  This is what electronics has lost, what made it fun, will anything new be discovered by the next generation who are not allowed to take a risk and try something different?  Computer simulations are great but they do not have the thrill of feeling the resistor get hot (or better still, see it smoke, that is how you learn). Good Luck.

  3. TomC123123
    May 13, 2015

    Ken:

     

    Firstly – your posts are always thought provoking, on point and inspiring.

     

    Certainly an emphasis on the practical performance of real components is essential, but one must understand the theoretical performance of these components first. 

     

    Cheers,

    TomC

  4. ericha
    May 13, 2015

    There is a very good point here, but I think you've gone a little too far.  If you start talking about imperfections, you'll confuse everyone.  You first have to understand what the device is supposed to do to even know what the imperfection means. 

    However I remember in Engineering school spending an entire quarter analyzing networks with 1 Ohm resistors and 1 Farad capacitors.  That's didn't seem all that useful.  We never talked about limitations of real components; that does seem like a real loss.

    The other aspect that didn't get enough attention in school was how real circuits work.  Combining this with the limitation of real components seems like it could be very useful.

    Ultimately I agree with your point, however I think it needs to be taken more in context of how people learn, and what else they have to learn to be able to understand what you are talking about.

  5. kencoffman
    May 13, 2015

    One great thing about hanging out at Planet Analog is the very bright and opinionated denizens. I love this intellectual mud wrestling. Keep it up.

  6. D Feucht
    May 15, 2015

    Hey Ken,

    I appreciate the general sentiment in your comments but at the same time am aware that the best engineers have both a deep theoretical understanding and extensive capability at the bench. For them, theory and practice are so inextricably intertwined that it is not either-or but both-and.

    The best schools, such as MIT and CalTech, emphasize a deep understanding of the basic principles that will still be true a century from now. Engineers who can understand what they are doing from basic principles are more apt to discover the hidden assumptions in their thinking that are obstacles in achieving their technical goals. Knowing specs on the latest op-amps has its place, but understanding how to apply basic circuits laws and do algebra well (which means the ability to put math in a form that can be related to the circuit) is essential for success as an engineer.

     

  7. kencoffman
    May 15, 2015

    Dennis, you raise an excellent point and I shouldn't argue with you, but I've noticed there are different ways to master circuit operation and only in rare cases does the math define the circuit. I would sure argue that where diminishing terms get buried in noise, we should make sure the student takes a practical approach to simplification. The biggest thing I would try to get the student to grasp is the math is not the boss. The human is the boss. The math serves to describe or predict things, but it's purpose is to serve the human mind and in all cases, the equations should illuminate, not obscucate. Too many perfectly capable STEM candidates get turned off by unneccesary complexity and we should lead them to it gently. Maybe I'm wrong, it happens.

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