fan cart

A “fan cart” is a roughly constant-force device used in introductory physics labs. It consists of a fan (usually a model airplane propeller on a brushed DC motor) mounted on top of a low-friction cart. Students use it to pretend they’re learning something about force, acceleration, energy, etc. If you’ve ever taken an introductory physics […]

In an earlier post I described an Arduino-controlled fan cart. The driver I used was an L293D quad half-H chip, because I had one handy and was out of simpler parts at the time. It’s always bugged me that I was just controlling speed on that cart, since it’s possible to control direction with an