Simple, logic-controlled variable speed fan for fire-fighterbots and other wind-inducing experimentation (beans not required)
A fan on a motor by itself isn't amazing; actually quite commonplace. But this tidy little module is different in that it has an additional speed-control circuit that makes it a very handy tinkering tool.
Originally designed to be part of a Keyes fire-fighting robot system (search out a candle & snuff it), it's simply too cool to not have available for other purposes. Heat-sink power disappation. Micro swamp cooling. Helium balloon propulsion. The point is, you feed it 3 to 12 VDC, a pair of CMOS/TTL logic-level direction signals, and you are done!