Gas gauge calibration unit

Bobby,

Thank you for the kind words. I have been called many names, and it does not matter a bit. My real name is David, but the Kit is from working on Kitcars.

Back to the board. Designs have shifted to surface mount. Board costs are closely related to holes drilled, surface mounting eliminates holes. The surface mount parts take less materials and the manufacturing process is automated. The resistors and capacitors are very inexpensive in quantity, just cents. Through hole parts such as axial leaded resistors and radial leaded capacitors are now expensive, and hard to source.

I will try to use 1206 (0.12" x 0.06") and 0805 (0.08" x 0.05") parts. Even the 1206 are not easy to source, since they are considered old technology. Typically the parts are handled with tweezers. A small dot of solder is used to plate one side of foil, then the part is moved in-place and soldered on one end, then the other end soldered. I like to de-stress by quickly heating both ends, by moving back and forth. The part floats on surface, attracted by the surface tension of the solder, and centers on the pads.

My prototype is ugly and uses a an inexpensive phenolic single side foil from RS. It is what I had in my junk box. If we get board made they will be FR4, have solder mask, and silkscreen reference designators for parts locations. Assembly will be fairly easy.