Minimalist motor

[mklotz]

Someone asked me how a motor works so I put together this absolute minimalist DC motor as a demonstration.



Two stanchions made of bent paperclips support a coil of magnet wire above a Harbor Freight magnet. The coil is free to spin in the supports. A small power supply supplies a couple of volts to make it work. As the video shows, it hums right along.

Now, a puzzle for you to solve. This configuration of motor requires a commutator to work yet none is visible. How is commutation accomplished?