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Q: human powered generator ( No Answer,   2 Comments )
Subject: human powered generator
Category: Science > Physics
Asked by: pherz-ga
List Price: $100.00
Posted: 24 Mar 2006 11:20 PST
Expires: 25 Mar 2006 18:17 PST
Question ID: 711536
I want to build a bicycle (stationary) powered generator system for an
art project.  The generator (or alternator), linked to the rear wheel
of a bike on a stand, will charge a 12 volt car battery (batteries). 
The battery will then be wired to 2 small DC electric motors that will
turn the 2 moving parts (cylinders) of the art, which will weigh
approximately 5 pounds each but will be balanced upright on pivoting
vertical axles.  I also need to power 2 light fixtures, each likely to
be 12-18 inch florescent 12 volt tubes from an RV store.  I need to
know what type of generator/alternator to look for that can be easily
linked to the bike wheel on a stand, and that can be reasonably
powered by a person on the bike, and will provide enough power to run
the system..  My project requires that the cylinders turn at a
constant rpm of about 30, so I'm thinking I'll need a consistent
voltage supply to the 2 small motors; that's why I don't think linking
the generator directly to the 2 small motors will work, as the rpms of
the motors, and thus the cylinders, would vary with the speed of the
bike wheel. The 12 volt battery, consistently charged, should supply a
relatively consistent voltage to the small motors.  Please provide the
following, keeping in mind that your calculations require this entire
system to be powered by an average person on a bike:

specific type of generator/alternator, where to find it
type and size of the 2 small motors, where to find them
can the 2 small motors be wired to a device that can control and vary the rpms
do I need a voltage regulator? If so, what kind, where to find, and how to wire it.
suggestions regarding linkages - belts, gearing, etc.

Finally, I'd like to keep the system as simple as possible, and keep
the costs "reasonable".

Thanks - Pat Herz
There is no answer at this time.

Subject: Re: human powered generator
From: redhoss-ga on 24 Mar 2006 17:57 PST
It seems to me that having a battery would defeat the idea of having
to pedal the bike to make the cylinders turn.
Subject: Re: human powered generator
From: qed100-ga on 24 Mar 2006 18:32 PST
As far as the alternator is concerned, you can just purchase one off
the shelf from an automotive supply store.

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