your gonna need a psu of some sort as you only have a low current output from your projector. That isnt goint to run any relay. You may be able to get a basic plc that will do this but thats gonna need a psu too although some are 240v. I Doubt your projector has a DC power outlet.

but what I am trying to is achieve the same thing without having to use the 12v PSU.

Can't be done.

some reed relays work of tiny triggers but they can't switch mains, gonna have to bite the bullet and get a psu I'm afraid.

either that or hack the projector to draw power from there

Regards

Bellman

Oh - well I guess I need to find a place to hide a PSU then

What else is in this room, maybe something that has 12 ish volts?

As bellman says in that projector there will be 12 v somewhere, but it will be soldering iron time

There are two sockets on the ceiling, one for the screen, one for the projector - the 12v supply would need to come from somewhere near the projector; and a black brick plugged into the ceiling aint gonna look nice.

Yes, I have a 240v source but how would I use that in conjunction with a 12v trigger the projector gives when it comes out of Standby to On.

the projector cant sink enough power to drive a relay, unless you know of a 240v t relay with low voltage starts?

So when it comes out of standby, does it switch on 240v to anywhere on the projector where you can tap off??

Oh, no

if you want to modge the bulb connections or fan would drive a relay

Bulb may not be 240v

Id rather not even consider opening up my brand spanking new Sony