[Lab] human powered art

Richard Guy Briggs rgb at tricolour.net
Sun Jan 16 00:14:43 EST 2011 

On Sat, Jan 15, 2011 at 09:37:28PM -0500, Darcy Whyte wrote:
> Richard,
> 
> I'm going through the pages on your page on Human Power. There are a couple
> of good candidates there.
> 
> This one:
> 
> http://www.amazon.com/gp/product/B000TKAH04?ie=UTF8&tag=reneenerblog-20&linkCode=as2&camp=1789&creative=9325&creativeASIN=B000TKAH04
> 
> Looks a little pricey at well over 200 bucks.

That's what I had thought, but was willing to consider it...

> This cool pedal generator in the picture at
> http://mambohead.com/2011/01/using-a-stepper-motor-as-a-generator/ is 400
> bucks for everything. I think the thing to do is figure out what motor they
> are using as a generator on that one.

Woah!  That monsterscooterparts site with a 300w motor for $35 is the
right price!

> Does anybody know?
> 
> 
> 
> 
> On Sat, Jan 15, 2011 at 8:55 PM, Darcy Whyte <darcy at siteware.com> wrote:
> 
> > I guess another way to look at it is if I need 1000W to make toast. And it
> > takes 5m to make the toast. If we can get 50W out of a person, then they'd
> > have to peddle for 15m to charge a battery, then they could make the toast
> > in 5m. So it would take 20m to make the toast. (Assuming we've got a pretty
> > efficient generator and battery).
> >
> > But then we don't feel the real load of making toast since we've spread it
> > out over 15m. I wanted to make the power in real time. I imagined that a
> > person would guess (wrongly) that they could turn the generator and make
> > toast easily. But when they try it they will be surprised that they can't
> > sustain since the toaster draws too much current. So then they'd get their
> > friends to help gang up on the machine.
> >
> > So I was thinking of having some sort of spool with cable on it and people
> > could row (turning the spool), or even harness the cable to their hip and
> > run out for 20 feet, then return and do it again. If there were a long
> > enough spool so lots of people could be doing this action, then a team of
> > people could probably make the toast.
> >
> > I've got some interesting ideas of how to have people turn the generator
> > but I want to start with having one that's efficient and the right size.
> >
> >
> >
> >
> > On Sat, Jan 15, 2011 at 8:45 PM, Darcy Whyte <darcy at siteware.com> wrote:
> >
> >> Yeah, I think a stepper can be a good generator. But the problem I'm
> >> trying to solve is what size of stepper or electric motor would make a good
> >> generator for capturing electricity from a human. Apparently a human can
> >> average about .1hp. But can put out more power in bursts. So I was figuring
> >> that stepper might be too small.
> >>
> >> Do you think a couple of NEMA 34 motors is enough to capture energy that a
> >> person can generate?
> >>
> >> I think a car alternator is out since it needs electricity to generate
> >> electricity. I'm not sure their so efficient.
> >>
> >> Yeah, I figured for the toaster application we'd need more than a hp. I'm
> >> wondering if a NEMA 34 would be enough. Or perhaps a team of them (what size
> >> team?)
> >>
> >> Your numbers agree with mine on the number of people it would take. And
> >> that's part of the message in this art piece. The average person doesn't
> >> have a sense of how much electricity we use in terms of the work it's
> >> equivalent to (in terms we understand).
> >>
> >> So if it turns out it's 2 NEMA-34s to extract power from a human, I may
> >> need to look at about 10 of them in the toaster application.  (So people can
> >> team up to push the generators to make the toast.
> >>
> >> The page you made on human generators looks awesome. I'll go through those
> >> links and information.
> >>
> >>
> >>
> >>
> >> On Sat, Jan 15, 2011 at 6:12 PM, Richard Guy Briggs <rgb at tricolour.net>wrote:
> >>
> >>> 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!
> >>> http://www.thebackshed.com/Windmill/assemblyMini3.asp
> >>>
> >>> 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
> >>> 25...
> >>>
> >>> > 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
> >>> unmagnetized steel.
> >>>
> >>> > 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:
> >>>        http://tricolour.net/bicycle-generator.html
> >>>
> >>>
> >>> I just tripped on this site that may be of interest too:
> >>>        http://www.thebackshed.com/
> >>>
> >>>
> >>>        slainte mhath, RGB
> >>>
> >>> --
> >>> Richard Guy Briggs               --  ~\    -- ~\            <
> >>> hpv.tricolour.net>
> >>> <www.TriColour.net>                --  \___   o \@       @       Ride
> >>> yer bike!
> >>> Ottawa, ON, CANADA                  --  Lo_>__M__\\/\%__\\/\%
> >>> Vote! -- <greenparty.ca
> >>> >_____GTVS6#790__(*)__(*)________(*)(*)_________________
> >>>
> >>
> >>
> >

	slainte mhath, RGB

--
Richard Guy Briggs               --  ~\    -- ~\            <hpv.tricolour.net>
<www.TriColour.net>                --  \___   o \@       @       Ride yer bike!
Ottawa, ON, CANADA                  --  Lo_>__M__\\/\%__\\/\%
Vote! -- <greenparty.ca>_____GTVS6#790__(*)__(*)________(*)(*)_________________

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