OK, I'm really liking this idea...
I gotta explore one of my previous questions again. I did a lousy job expaining it.
If the receiving unit is powered by a very specific 12Vdc source, and the relays are rated to handle 10A/120Vac, 20A/12Vdc, then the relays are not supplying power to the circuit they control, right? The relays are nothing more than a switch. The circuit (that the relay switch controls) is unpowered until an outside power source is introduced to the circuit (a source voltage that is within the relay's capacity of 10A/120Vac, 20A/12Vdc). If I am wrong, then why would the receiver specify a power source of 12Vdc, but offer an entirely different range of handling capacities for the relays?