Dave,

As a novice I don't get exposure to best practices so this advice is very welcome. I will copy the info down and study it carefully. It will certainly be implemented in future designs that I explore. In my previous version of this control board I used relay driver IC's with single coil latching relays. They shared the same +5 and gnd traces with the PIC however. As far as sourcing current at the pin, since these relays are dual coil latching I only pulse them and no two relays are pulsed at the same time so I felt safe that I was not exceeding any pin source capability.

I appreciate your suggestion that I should have caps for the display power. I will do further research on how to accomplish this.

I think your last remark is on the money. As I mentioned in another reply, I run the trolleys off the overhead wire at times (I can switch between rail only & rail with overhead wire.) When running off the overhead, the trolley caenary arcs plenty. Talk about a "dirty" operating environment!

I appreciate your comments.