In case its of use, note that Green Power Science has some videos on this subject and also offers a geared DC generator which might be useful.

See: http://www.greenpowerscience.com/BIKEGENERATOR.php .


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As far as hand crank electric generators, most of the ones sold to the public break in a matter of days or weeks. A notable exception is the Motorola Freecharge generator. It was designed for charging cell phones, but is extremely durable. I attached alligator clips to several and provided them to Science Museum visitors to learn about electricity. They've been running for several years without problem!

Here is a source: http://bellsouthpwp.net/p/a/pagerboy/
and a photo:

How's this project going?
Need help?

Pete

One more query: What's been the outcome of this project? Anyone know?

I delivered and set up the bike generator for them the night before they opened.

It turned out- unsurprisingly- that the amount of work required to power their lights was vastly more than could be reasonably expected of a person of normal fitness. Rough guess was a 6-8:1 ratio of pedaling time to use time, and that was NOT easy pedaling. Think riding a BMX-type one-speed bike up a steep hill and you're about right on the amount of effort.

In the end, though, I'd call it successful- that fact alone did a great deal to call attention to the degree to which we take energy for granted, and that was the goal of the project.

I haven't heard back from them since then, however.

Hello TCMakers -we should have followed up here after the show opened! Mike is right, the project was a success in our eyes, too - the audience had opportunities to pedal the bike and we spoke with interested folks before and after the show about how the system was put together and how much work goes into generating electricity.