The local association’s meeting was canceled tonight due to snow. This gave me a little bit of time to work on the honey stick machine that’s been left sitting for awhile while I caught up on other things. I was able to finish and test the final 4 to 8 decoder previously built on a prototype board. For testing I connected to the DC driver board simply to have a display of the output on the LEDs. I was a bit worried at first because it didn’t work at all, but then I found some insulation had melted allowing two wires to come into contact with each other. After fixing that issue the circuit worked perfectly while running it though some 20,000 on/off cycles.
One thing I learned building this circuit was how slow and tedious it can be building these circuits on prototype PCBs. The boards have no circuit traces and every wire needs carefully positioned and soldered by hand. Should I get to the point where I can produce even a small number of machines, I’ll definitely be looking to design a printed circuit board. Fortunately that’s almost as easy as desktop publishing now with software like PBC123 that lets you design and order custom circuit boards in small numbers.