Standard PCB terminals placement
Inputs age placed on left or bottom side, outs - on right or top side, positive power supply terminals at upper side (closer to
top), and negative or ground - closer to bottom side. Signals going through another PCB, requires shorter wires, and this reduce
"web" of wires.
Standard PCB terminals placement (with two power supplies)
This is 50x100 (or 50.8x101.6) mm basic terminal placement. Keep common bus (ground wire) as thick as possible, this ensures
high current compatibility without reliability issues (heating and such). Higher voltage terminals are placed higher, this
rule persists in case of more than 2 power supplies usage. Good practice is to keep DC and AC voltages on separate PCB, this
does not relates to PCBs with relays (or other AC switching devices requiring DC power supply) only.
Same logic is for signals. In this template signals are going from bottom to top. Anyway, your PCB can require another terminals
placement, for example DC power terminals at left and AC switching terminals at right.
Simple things is working better, and standard is best solution of simplifying for all.