22 Jan First revision of the DCM MPPT design now up
Hot off the presses! Download!
The new tracker is vastly different from the old one. The biggest difference is that the trackers now run in discontinuous mode boost. That means the inductor current hits zero on every cycle. This has the advantage of being much more efficient with extreme boost ratios by eliminating diode reverse recovery loss. The inductor is also substantially smaller, so the trackers are much lighter and more power dense.
Other new features include more LEDs, a hardware based overvoltage lockout on the output, a 16×2 LCD screen, and integrated board-level precharge. The other “big deal” is that these boards are now powered off of the solar input rather than the CAN bus. They’ll operate over the entire range from 5v to 60v on the input, but I’ve chosen input capacitors on this model that top out at 35v.
As usual, you’re free to use the design for your own purposes, but please contact me for permission if you intend on using them commercially. I’d also like to thank Robert Pilawa out at MIT for his contributions to the inductor selection process. They have a really friendly and very talented solar car team that he is a part of. Now we just need to figure out how to beat them.