[dorkbotpdx-blabber] Re: solor powered Dorkboard, fact or fiction?

[Donald Delmar Davis]

See page 303 of the datasheet.


On Mar 31, 2009, at 7:33 PM, Laen wrote:

> A running dorkboard on its own (not running any external components
> like LEDs) is about 20mA at 5V.  I don't know what it would be at 3V.
> I think the Atmega168Vs run a bit less, but I haven't hooked them up
> to a meter.
>
> For the capacitor, I _think_ the math goes like this (someone correct
> me if I'm wrong!)
>
> Volts^2 * Farads = Joules of energy storage.
> Volts * Farads / amps = the amount of time it can put out that amount
> of amps.  In practice, it'll be much lower, because the voltage will
> drop as you drain power.
>
> So:
> a 3V, 1F supercap would run a Dorkboard for:
> 3V*1F / 20 milliamps == 2.5 minutes.
>
> (By the way, google Calculator handles these conversions really well.
> Enter "3V*1F/20 milliamps" into a google search, and you'll get that
> answer.)
>
> -Laen
>
> On Mar 31, 6:36 pm, scott winner <sc... at scenbot.com> wrote:
>> I am looking for some advice or tips.
>> Here is my project,
>>
>> I want to run my Dorkboard on solor
>> power.  Don is setting me up with a 3 volt chip.  That will help a
>> lot.  I am going to model the control after the Solorbotics voltage
>> trigger; solor energy is stored in caps then dumped into the
>> Dorkboard when a critical voltage is reached.
>>
>> So my question for the ether is, what
>> size caps?  How much power needs to be stored to run the Dorkboard?
>> No motor function, just to blink the light.  I know how much to run
>> the motors that will be on a separate circuit.
>>
>> Ok go nuts folks.
>>
>> _________________________________________________________________
>> All-in-one security and maintenance for your PC.  Get a free 90-day  
>> trial!http://www.windowsonecare.com/purchase/trial.aspx?sc_cid=wl_wlmail
>>
>> _______________________________________________
>> dorkbotpdx-blabber mailing list
>> dorkbotpdx-blab... at dorkbot.orghttp://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber
> _______________________________________________
> dorkbotpdx-blabber mailing list
> dorkbotpdx-blabber at dorkbot.org
> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://music.columbia.edu/pipermail/dorkbotpdx-blabber/attachments/20090331/cc0c616d/attachment.html