I've got it out in the sun right now, was curious about the load voltage of the panel, with the current setup. Only getting 12.6 volts, but there are scattered clouds. Only got up to around 77 F to day. Really getting tired of the chilly weather
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Did some digging around in the parts bins, found that I have 10 x LM2576T-ADJ. Looks like I have the right part on hand. The enable pin has a 1.4 volt threshold (ON<1.4 volts>OFF). Huge data sheet, need to figure out which parts are the fixed out, and which pertain to the adjustable parts I have on hand. It calls for a fast diode, not sure what I have in that department. Also need a 100 uH inductor, don't have a huge variety, not sure of the values. Take a closer look tomorrow, still have to finish up a Christmas gift. Few more parts, test, and shove it in a box...