[Lab] human powered art
Richard Guy Briggs
rgb at tricolour.net
Sat Jan 15 18:12:24 EST 2011
On Fri, Jan 14, 2011 at 07:14:29AM -0500, Darcy Whyte wrote:
> I would like to make a human powered generator for an art project.
I've been wanting to build one for a while now...
> I am curious if a couple of NEMA 34 motors is large enough to capture all
> the power that a human can generate.
My understanding is that a stepper is not the kind of motor that can be
used as a generator. Wait! I stand corrected!
What is most commonly used to generate DC is a commutated DC motor.
A car alternator will also work. It is an AC generator with a
rectifier, but they tend to be a lot less efficient. It also needs a
power supply bias to get started (say, a car battery under charge) since
there are no permanent magnets and it uses a field coil.
My understanding is that motors are typically 80% efficient, while
dynamos closer to 50%.
Do you have a link for your NEMA 34 motor specs? I've seen anywhere
from 50W up to 500, so it sounds like those might work!
> I'm looking at a couple of applications.
> 1) To run a 120V toaster. I suspect this might need as many as 5 people to
> peddle. Also to run a 60W incandescence bulb.
A toaster is going to need 3 top athletes (400W ea) or about 8 fit
adults (150w ea) to run. For kids (50w ea), it is going to be more like
> 2) To charge a 12V battery.
One will work here, it'll just take longer...
I wanted to power a TV, or at least to power the "on" circuit. Other
ideas we had was to use a human powered generator to power parade float
lights or moving parts.
> I'm suspecting that a stepper motor is a good candidate to make the
> electricity. I think the first part of the project is to make up some BOMs
> that show what motor to use, the RPM that it would require and parts for a
> rectifier and whatever else is necessary to operate in these applications.
I've got lots of small ones, so I can try some tests and see. I
wouldn't have thought they would work because the rotor I thought was
> Does anybody know of any existing projects or have any recommendations?
There are lots out there that I have tripped upon in the past... I
threw together this page to summarize:
I just tripped on this site that may be of interest too:
slainte mhath, RGB
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