Goal: Control direction of a DC motor using an H-bridge.
Materials: I found a fan in the ITP junk shelf. Unfortunately, all the variable power supplies in the shop were missing cables. So, I could not try the fan out with a higher voltage. It ran with the 5 volts from the Arduino, but was not very powerful.
A button on the breadboard reverses the direction of the fan when pressed. I tried to demonstrate by using the fan as a fan, then as a vacuum, but due to the weakness of the fan at 5 volts, it didn't create enough vacuum to pull even some loose cotton. So here's a demonstration where I simply place the cotton behind the fan to show it blowing in the other direction.