That was the thought - to modify an existing DC to DC converter and change the circuit. Not really wanting to go as far as in full redesign though. I am thinking a buck converter might be easier to modify to add this manual control. I'd love to find a device with a fixed cap or resistor I could modify with a variable unit and get enough variation to find Vmpp under various conditions on my 16.5Vmpp nominal panels.
I may get to a simple automated circuit next. I may find out that I can live with a single set point in the middle of the range of Vmpp throughout the day and settle for a non auto tracking unit. I may decide that there is not enough gain in MPPT (via my manual tracking of the powerpoint over a few days in some different conditions) for me to even consider it with my setup.
But I crave real data and results vs so much hype around the MPPT products.
Jim
