Destroying Electronics to Make a Case for Algebra

I’m finding a lot of half-written blog posts in my drafts folder. This is another one of those things that actually happened a year or two ago and I never finished writing about it.

We are finally embarking on our electronics course, using Make: Electronics (Learning by Discovery) as our guide. It took a while to find all of the required parts, but we eventually did. If you need to find parts, I recommend: Digi-Key and Mouser Electronics. You can (or used to be able to) buy an already-assembled kit of parts from the author, but it included a lot of things we already had around the house, so it wouldn’t really help us save anything.

One reason I really like the book is that it encourages you to destroy things in order to see how they work. Often people are held back by worrying they might break something. It takes a lot of anxiety out of the situation if you are encouraged to break it!

For example, one experiment involves destroying an LED by hooking it up to the battery without a resistor. My son really likes LEDs though, so he really didn’t like the idea that we were killing them in order to enjoy ourselves. That motivated him to learn how to put resistors in the circuit to keep the LEDs from being destroyed.

Then we discovered that if the resister is too strong, the LED gets dim. He didn’t like that. So I showed him how the voltage, resistance, and current are related — Ohm’s law. He could use Ohm’s law to protect his precious LED by figuring out the exact resistance to make the LEDs as bright as possible without breaking it.

The catch is that you need to use algebra….

Here’s a great Ohm’s Law simulator on PheT: Ohm’s Law

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