Basics: Transistors and the Careful Placing of Impurities

(Editors Note: this blog post was first published on a, which has now been merged into

This YouTube video from the Acme School of Stuff (circa 1988) is a blast from the past. Despite it’s age, the info is presented as well as I have ever heard. It’s a brief introduction to electronics, but specifically it talks mostly about transistors and what they do, but not necessarily how (or maybe more accurately, why) they work. The host states, “transistor are almost impossible to explain.” The same can be said for electricity in general.

The key to transistors, is what the host refers to as the “careful placing of impurities.” These impurities are also know as semiconductors because they conduct electrical current under certain given circumstances.

Basics: Vacuum Tubes

(Editors Note: this blog post was first published on a, which has now been merged into

When I was a kid, I knew that televisions, radios and all sorts of electronics used vacuum tubes prior to the invention and widespread use of transistors. In fact, the black and white television on which I watched Gilligan’s Island used a special type of vacuum tube called a CRT (cathode ray tube). What I didn’t understand was how a vacuum (the household appliance used to suck dirt out of the carpet) made all these electronic devices possible. It was mind boggling. I didn’t think much of our vacuum, but it somehow held a secret I could not understand.

Well, it turns out that it was just a misunderstanding. My vacuum wasn’t responsible for the electronics revolution. The term vacuum tube was used to describe the glass tube that most of the ‘air’ removed under low pressure and filled with inert gases. A vacuum is a place that is empty of matter. If the tube was filled with air…that would not be a vacuum, since oxygen and other gasses in the air are matter.

But a vacuum tube is not truly a vacuum. They are manufactured under low pressure conditions (not no pressure conditions) and the gases inside are replaced with gases that won’t react. Then they are sealed while still in this condition making a near vacuum. It’s just that ‘near vacuum tubes’ never caught on.

Well, even with this misunderstanding cleared up, I still didn’t understand how vacuum tubes made the miracle of Gilligan’s Island possible. Turns out that if you understand how vacuum tubes work, it makes a lot of other electronics easier to understand too.

I found this video on YouTube. It’s a 21 min movie made by Westinghouse in 1943. And it’s fascinating, not to mention historically interesting when you note how many references it makes to the war effort. If I would have only seen this movie back when I was watching Gilligan’s Island, maybe I would have seen Gilligan and my vacuum in a different light.

First Boards Have Arrived

(Editors Note: this blog post was first published on a, which has now been merged into The board has now been renamed S2Duino. S2 stands for either “single sided” or “super simple.” This post is published exactly as it appeared).

On Saturday, the first batch of boards arrived. While these are not the final production boards (ordered before the final design was settled upon), they demonstrate the quality of the final boards. I am very excited and impressed. Final production boards should be here in a couple of weeks.