I have two low power 12 volt circuits (C1, C2) that operate relays. I want to control these with two SPST switches (S1, S2) in a Boolean manner: (S1 OR S2) for C1, and (NOT S2) for C2.
Can these circuits be wired in parallel off the same two switches, using relays for the logic gates as shown below? Will there be any negative interactions between these logic circuits, or these and the relays that C1 and C2 themselves control?
Best Answer
Yes the relay coils can be wires in parallel so each switch can be SPST and the electrical supply for the lights can also be in parallel,
You appear to be proposing this circuit, which will work.
simulate this circuit – Schematic created using CircuitLab
But two relays in parallel can be replaced with a relay that has more contacts. it's usually cheaper this way.
simulate this circuit
If the two lamps have the same power source you could also use the same relay in both circuits (so you only need two sinlge pole relays)
simulate this circuit