Rawrbot is HBL’s “official” mascot. Here is a vector drawing I made, based on a whiteboard sketch a bunch of us worked on last year. (PDF) Here’s the little guy on a ruler intended for laser cutting. …

Power, Volts, Current, Resistance. There are a bunch of charts floating around that describe the relationships between these four variables. I didn’t like any of them, so I decided to make my own. (PD…

I made a basic singing arc, based on this Instructable. It uses a TL494 to switch a MOSFET very rapidly, dumping current into the primary coil of a TV flyback. The air rapidly heats up when the spark …

I got my first home computer for Christmas, 1982 (about a month before my 8th birthday). It was a TI 99/4A with a speech synthesizer, built-in BASIC interpreter, and audio tape storage device. I …