Comments on: Exercise Bike Generator Demonstration

By: marcus

marcus — Sat, 16 Jan 2010 04:04:51 +0000

True, parasitic generators aren’t so good on a riding bike, especially now that battery-powered lights can be so efficient. It takes a lot of energy to overcome wind and rolling resistance, and, as you say, to climb hills. All that energy is usually wasted on a stationary bike, though, so it makes some sense to try using it. The kids using this rig don’t have much trouble cranking out 100 W or more for short periods. I’ve heard of folks using a similar rig (with a regulator and battery) to power their kids’ TV, video game, or computer; as incentive for exercise. I seem to recall that top cyclists can generate several hundred watts for extended periods. (YMMV!)

By: Keith

Keith — Sat, 16 Jan 2010 00:44:36 +0000

My first bicycle as an adult had a built-in dynamo generator in its front hub and an included light. It was only 2.4W; I can’ t imagine powering much more than that. In fact, the light wouldn’t even work going uphill, so I had to purchase a 10W halogen light so that I wouldn’t be riding illegal at night.

By: marcus

marcus — Thu, 29 Oct 2009 10:55:20 +0000

Sorry I didn’t reply to this before. I got distracted. As pictured here, there’s nothing very special about the setup. The motor is wired directly to the load. For a serious application, you’d want to add a storage battery, at least. This would be wired in parallel to the load. If there’s any chance of exceeding a safe operating or battery charge voltage, you’d also want some sort of voltage regulation. That’s a problem I carefully avoided, though.

By: Green Energy DIY Fan

Green Energy DIY Fan — Sun, 11 Oct 2009 12:43:04 +0000

Hello Marcus,
Thanks for this cool blog entry. Care to post some drawings on the setup of this power generator? I plan to do the same at my school on a science fair, and this is exactly what I have been looking for.
My other plan is to do the same but with a smaller solar panel, so kids can see how powerful these things are.
Cheers,
George

By: Robert Smith

Robert Smith — Tue, 28 Apr 2009 03:42:37 +0000

I found your blog and read a few of the posts. Keep up the good work. I am looking forward to checking out more from you in the future.