Sunday, November 22, 2009

PCB TEST




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.

9 comments:

  1. My mouth is watering.....Sorry meant to say it looks fantastic. Cant wait! Good job Fritz!
    Shawn D

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  2. I'm really getting worried about you Shawn....It says at the bottom of the board "Not for human consumption" :))

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  3. This thing is super slick. I'd love to buy a pcb and schematic and a parts list to build one. I've got batteries galore and I've got other things which a small spot welder would be great for.

    keep us posted!

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  4. I am very impresssed with the progress you have made. I have soldered circuits for many years but never surface mount components with a hot air iron. Is that something the average hobbyist can do?

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  5. I'd be interested in 1 or 2 boards if your proto will join titanium (small parts)
    get a price together and if you need some Ti to test with I can send some

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  6. Brian, you just need steady hands and good eyes. The parts are small but it is really easy to do. Place a little solder paste on each pad, use tweezers to put your component on the right spot and then heat the component up with your hot air soldering iron. The solder will start to bubble and then melt making beautiful clean and shiny joints. It is much easier, faster and cleaner than through hole soldering. To answer your question ....YES an average hobbyist will be able to do it and never use the old through hole method again.

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  7. It depends on how thick the titanium is. I have no idea if it will be able to weld it though...send me some samples..email me and I'll give you my address

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  8. Maybe I am blaind but where can I find a E-mail addy for you Fritz?

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  9. er.. that would be blind.. I cant spell either evidently.

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