<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">See page 303 of the datasheet. <br><div><div><br><div><br><div><div>On Mar 31, 2009, at 7:33 PM, Laen wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>A running dorkboard on its own (not running any external components<br>like LEDs) is about 20mA at 5V. I don't know what it would be at 3V.<br>I think the Atmega168Vs run a bit less, but I haven't hooked them up<br>to a meter.<br><br>For the capacitor, I _think_ the math goes like this (someone correct<br>me if I'm wrong!)<br><br>Volts^2 * Farads = Joules of energy storage.<br>Volts * Farads / amps = the amount of time it can put out that amount<br>of amps. In practice, it'll be much lower, because the voltage will<br>drop as you drain power.<br><br>So:<br>a 3V, 1F supercap would run a Dorkboard for:<br>3V*1F / 20 milliamps == 2.5 minutes.<br><br>(By the way, google Calculator handles these conversions really well.<br>Enter "3V*1F/20 milliamps" into a google search, and you'll get that<br>answer.)<br><br>-Laen<br><br>On Mar 31, 6:36 pm, scott winner <sc...@scenbot.com> wrote:<br><blockquote type="cite">I am looking for some advice or tips. <br></blockquote><blockquote type="cite">Here is my project, <br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I want to run my Dorkboard on solor<br></blockquote><blockquote type="cite">power. Don is setting me up with a 3 volt chip. That will help a<br></blockquote><blockquote type="cite">lot. I am going to model the control after the Solorbotics voltage<br></blockquote><blockquote type="cite">trigger; solor energy is stored in caps then dumped into the<br></blockquote><blockquote type="cite">Dorkboard when a critical voltage is reached.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">So my question for the ether is, what<br></blockquote><blockquote type="cite">size caps? How much power needs to be stored to run the Dorkboard?<br></blockquote><blockquote type="cite">No motor function, just to blink the light. I know how much to run<br></blockquote><blockquote type="cite">the motors that will be on a separate circuit.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Ok go nuts folks. <br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_________________________________________________________________<br></blockquote><blockquote type="cite">All-in-one security and maintenance for your PC. Get a free 90-day trial!<a href="http://www.windowsonecare.com/purchase/trial.aspx?sc_cid=wl_wlmail">http://www.windowsonecare.com/purchase/trial.aspx?sc_cid=wl_wlmail</a><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_______________________________________________<br></blockquote><blockquote type="cite">dorkbotpdx-blabber mailing list<br></blockquote><blockquote type="cite">dorkbotpdx-blab...@dorkbot.org<a href="http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber">http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber</a><br></blockquote>_______________________________________________<br>dorkbotpdx-blabber mailing list<br><a href="mailto:dorkbotpdx-blabber@dorkbot.org">dorkbotpdx-blabber@dorkbot.org</a><br><a href="http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber">http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber</a><br></div></blockquote></div><br></div></div></div></body></html>