I'm trying to turn on a switch (same 120vac different branch) via a resistive load circuit branch. If I were to use an AC relay, it wouldn't work as far as I can tell. In other words, if I were to put the (high impedence) coil of the relay in series with the resistive load (up to 12amps 60hz AC) then the resistive load would stop working. Is there a way to do what I'm trying to do (preferrably with passive components such as relays)? Perhaps a low impedence relay if one exists?

 

connecting a relay in PARALLEL is the common method of application. Putting them in a series configuration is seldom done.

You must, of course, use a relay designed for the type of voltage in use. In this case you need a relay designed to operate on 120 VAC.