May's feature

Educational hack.

We had a bicycle day at my favorite local institution. I helped out by building a two-station, people-powered electrical generating set.

Peak output was about 350W, and that made all six light bulbs glow convincingly.

Status: Successfully deployed. It's waiting for either next year's event or some other opportunity to help people to understand just how hard it is to keep lightbulbs lighted.

The bikes came from our transfer station; cast-offs. (Amazingly rich society we have here.) The generator is just a permanent magnet DC motor. Before the next outing, I need to spin the generator spin a little slower; it produces too high a voltage.

It's pretty cool to see a mom or a pop or a kid get off the thing, huffing, with a visceral sense of just what it takes to keep a 75W bulb going. Next, refer them to the chart that shows it takes about 300 such "pedalers" to make an SUV go down the road at 55 mph... it makes an impression.

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