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.