Been a while since I posted on this subject. I have had the PCB fabricated and assembled one BCD controller. It tool a long time to solder in all the parts, but eventually it got built. After some initial testing of the PCB I found that I had messed up ONE circuit, the one that controls the output enable relay. I had wired it up and found later after looking at the schematic that I have back flow of voltage though it. And about the only fix was to use diodes or just pull the relay and add a jumper. The latter was the way to go as it’s really not needed.
I wired in a box with some 120v hot dog shaped lamps and made a short video of the board in action. In watching the ammeter on the power supply it draws in the 3 amp range worse case. The BCD switches and LED’s all over the board make it a fun thing to play with.
Now just need to find the time to build a few more of these up, and figure out how I’m going to drive it.
Here’s the short video on the decode board –