Saturday, August 14, 2010

Control Board Transistor, etc., Day

I had a good working session today, during which I installed all the transistors on the control board, as well some voltage regulators, crystals, and a socket for the PIC CPU for this board. Starting with this post, you can click on these small pictures to get the big view.

Here is the control board so far. Today's assembly was quite straightforward, except for one possible mishap. After soldering Q5, I discovered it had slipped prior to soldering such that it was way above the board. After some attempts at reheating (and being very pleased with how the new solder pump worked!!), I finally clipped it out, cleaned the holes, and did it again. So, I hope Q5 survived the reheating.
The crystal cases need to be grounded. The procedure described in the manual for doing so was very straightforward and worked well. I found it handy to tape the little piece of grounding wire down to hold it in place for soldering.

The other thing I did today was rig up a grounding clamp on a local cold water pipe, ran a piece of antenna wire down from it, and clipped my wrist grounding strap to the wire. Hopefully, this is an adequate grounding scheme. In any case, I kept the wrist strip on while handling all the transistors, etc., today.