Greetings, I would like to build a circuit that would switch 2 separate AC power sources to a single load. Here's what the circuit should do: Circuit has single AC output to a system which utilizes AC current Circuit has both a 120 VAC and 12 VDC input. 12VDC circuit is connected to an inverter circuit to produce a separate 120 VAC input. In the event AC current is present in the AC input source, switch the circuit to source the load with the AC input Switch the circuit to the 12VDC/inverter input if the AC input current is not present Power requirement is for the output is 150 watts So basically, the 12VDC from the input goes through an inverter circuit to produce the first AC source, a separate AC input connects directly to a 120VAC source to produce the second AC source, and a switch or relay switches the first or second AC source depending on the conditions listed above. I have enclosed a jpeg image to better illustrate what I am saying. In this diagram is a DPDT switch which would allow manual switching but my intent is to use a relay to provide this functionality. My question is if there is a relay that would perform the function of the switch and if so how would it be connected? Specifically, can I use the AC voltage from the second input source to drive the relay? Thanks in advance for your help.