<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>LM2673 could work for this, assuming you put a chunky diode to make sure it's ever so slightly under 40v:</span></div><div><br><span></span></div><div><span>http://www.ti.com/product/lm2673#modalWin<br></span></div><br>National/Texas Inst. site has a great new ways of letting your search for chips like this, just input your data on the right hand side. <br><div><br></div> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Jake <jake@spaz.org><br> <b><span style="font-weight: bold;">To:</span></b> "noisebridge-discuss@lists.noisebridge.net"
<noisebridge-discuss@lists.noisebridge.net>; terminationshok@gmail.com <br> <b><span style="font-weight: bold;">Sent:</span></b> Thursday, July 5, 2012 3:22 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> [Noisebridge-discuss] 40 volt solar panel<br> </font> </div> <br>
What you need is a buck converter, which is a DC to DC converter which <br>steps down a higher voltage to a lower one.<br><br>You need one which can accept 40 volts or more, can be adjusted to output <br>exactly 14.1 or up to 15 volts (depending on the chemistry of your <br>battery, how long you want the battery to last, etc) and it has to be able <br>to handle the wattage/amperage that you will be doing.<br><br>How many watts is the panel? How big is the battery? These will help <br>determine how many amps you will be passing.<br><br>More fancy solar charge controllers are available, and you might want to <br>choose one if this is a long-term investment like a water pump on a farm <br>or something. A fancy charge controller does something called Maximum <br>Power Point Charging, which you could do with an arduino, but i digress..<br><br>-jake<br><br>Dan Cote wrote:<br>Can anyone help me build a charging circuit for a 12 volt lead
acid<br>battery? There is a 40 volt solar panel on the roof that I would like to<br>make use of.<br><br>_______________________________________________<br>Noisebridge-discuss mailing list<br><a ymailto="mailto:Noisebridge-discuss@lists.noisebridge.net" href="mailto:Noisebridge-discuss@lists.noisebridge.net">Noisebridge-discuss@lists.noisebridge.net</a><br><a href="https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss" target="_blank">https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss</a><br><br><br> </div> </div> </div></body></html>