Utility Cycling - 12 v DC generator for a bicycle?

After watching Soylent Green the other day (Soylent Green is people!) and noticing that the protagonists had to power their apartment with batteries that were recharged by a bike hooked up to a generator, I was wondering if there is a commercially available (or easily made) bicycle generator system?

I could see using one here in Florida during hurricane power outages.

A buddy of mine has a set up like that.He's using a GM alternator(from a car) that uses the wider serpentine belt and he removed the tire from the rear wheel of his mtn bike and runs the belt around the bare rim.He uses to it to power his tv.It's a little RV 12 volt one.He's planning on trying a power inverter to be able to run 110v to run his computer.Once he has the bugs out of it,I'm gonna try it to.

I remember reading somewhere that if you wanted something bigger than the standard-size dynamo-type generators, to get a VW generator for the older VW's from J.C. Whitney. I haven't tried this myself. (Alternators for modern cars require electrical input from a battery as well, but the older generators did not).

What do you want to power? You can already get radios and flashlights that you crank the handle to generate the power. Haven't seen a TV like that. But if you kept a car-size battery charged up from AC , you could probably run a small TV a lot longer than you'd care to pedal it. I don't think you could pedal enough power to keep a fridge running.

Keep in mind also that the voltage output of a dynamo varies depending on its rotational speed. I have a Shimano Nexus hub, rated for 6 volts, built into the 16" wheel of my folding bike. It generates 15 volts at fairly moderate speeds (so I have a regulator that limits its output to 12 v, with which I run lights made for a car).

You can try Peter White:
http://www.peterwhitecycles.com/lightingsystems.htm

He has several choices of generators and lights.

Or are you looking for something else?

You can hook up that generator to the back wheel, and you could use the generator to power an e-bike conversion. Thanks to the mechanical advantage from your gears all you have to do is pedal it up to speed, then the e-bike motor takes over, powered by the generator. You can use the excess power from the generator to power your appliances while you relax on the couch!



;)

The only 12V bike generator I remember seeing is the Dymotec S12 bottle dynamo from Busch & Mueller (http://www.bumm.de/index-e.html). If it's anything like their 6V models (S6), it's a great product for its intended use. For home use you would require something with more wattage though, as suggested above.

Another option might be solar or wind power. Wind generator manufacturers claim their products can easily power a (small 12V) fridge year round. Solar power has been all the rage here for summer cottages, although cottage fridges are often powered by liquid gas to keep it simple. Anyways, get a panel and/or a windmill, add enough batteries, charger and control electronics and you have a system that will provide enough power for essentials.

--J

Here is a link to a bicycle trainer with a generator that is rectified to direct current.

http://www.econvergence.net/electro.htm

Are there any "on bike" generators that produce direct current? Thought it might be neat to set something up on my bike that could charge a battery as I ride, but all the dynamos out there seem to produce alternating current only.

http://www.humboldt.edu/~ccat/pedalpower/
Another link with many bicycle driven appliances.

Here is a link to a bicycle trainer with a generator that is rectified to direct current.

http://www.econvergence.net/electro.htm

Are there any "on bike" generators that produce direct current? Thought it might be neat to set something up on my bike that could charge a battery as I ride, but all the dynamos out there seem to produce alternating current only.

A rectifier and a capacitor is all you'd need to convert the AC to DC...

Rectifier converts the AC to rippling DC, and the capacitor smooths the ripples.