[Lab] human powered art

Sat Jan 15 21:37:28 EST 2011

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.

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.

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__(*)__(*)________(*)(*)_________________
>>>
>>
>>
>
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