Question on Relays and Solid State Relays pls...?

Question

Hi, I have a varied 12v output which goes "up and down" in voltage to make a light bulb dim, but I want to use the 12v controller to vary a mains light bulb, I could normally a relay but is there like a relay that varys that if the lower voltage side changes then the mains side varys as well, I've heard of solid state relay working - does it?....Thanks

Answer 1

A relay is a switch.  It doesn't matter whether a conventional electro-mechanical one or a solid-state one, it's still just a switch.  

So no, I'm afraid you can't use a relay to do what you describe.

If your variable 12V supply is a.c. then you could use a transformer to control a mains bulb.

A mains to 12V transformer used backwards.

You variable voltage to the winding which is supposed to be the secondary, and the output to the bulb from the other winding.