I was asking ?'s over at the cnc4pc yahoo group. Here's the ?'s:
I've been helping someone with their control box set-up and have a few
questions about the c11 that didn't come up when I was hooking up my c11g.
The c11 has a usb cable for getting the 5v for board and also has
connections for a 5v & 12v wall wart.
1) If your using the usb do you need the other 5v & 12v wall wart?
2) if your using the 5v & 12v wall wart do you need the usb 5v?
The person I'm trying to help has both.
1) Does he need both?
2) What would happen if he used both?
And here's the reply:
The C11 is a fully optoisolated board. That means that it has two completely independent circuits. The currents of these circuits needs to be isolated from each other. That is way you need two power sources. One power is for the side of the circuit that interacts with the PC and the other power connections are for the other side of the circuit.
Yes, you could use one power supply to power both circuits, but you will loose optoisolation on the grounds.
It sounds like you also need to power the other power connections (5v & 12v).
cnc4pc sells a wall wart power supply (5v & 12v)
If you're not going to use the 12v circuits you may be able to use a 5v (1.5amp+) wall wart to power the other circuit.
Just a couple of ideas. This electronic talk above is above my head but, thats what I got from the the above response from the cnc4pc group.