Sunday, November 22, 2009
I've spent this weekend putting the new PCB together( I actually had it built before Friday) and it was very easy to build. You will need magnifying glasses, a good light and a hot air soldering iron for the surface mount components. The rest of the components are soldered at the bottom side and the solder gets pulled into the holes so no soldering is necessary at the top. There are two problems however, I screwed up on the solder mask on the Mosfets and you have to scratch the mask off around the solder points to get a bigger solder area and Diode 10 needs to be turned around.
The charging speed is so fast with a 12 Amp supply that when the capacitor reached it's set point and the mosfet kicks in when the voltage drops 0.1V that it actually overshoots the set point by 0.4V before turning the Mosfet off. I've been writing some really complicated code to try and fix this issue.