Using a 12 volt trigger to raise/lower a screen.

This is a help request. Could someone possibly come-up with some advice regarding the control of devices using the ubiquitous 12 volt trigger.

I'd like to automate the switch-on of an AV amp and an Epson projector with the raising/lowering of a motorised screen.

The amp has selective 12 v triggers out based on input selection, and no 12v trigger in. The projector has a 12v trigger out, and again no 12 v trigger in. The AV amp and the projector can be made to interwork via infa-red, it is the screen that is the problem.

I'm therefore looking for a device that would accept the projectors 12 volt trigger, and momentarily (1 second or so) close a contact when the trigger becomes present. When the trigger drops, close a different set of contacts, again for 1 second or so.

Wonder if anyone has any ideas?


Thanks anyway for reading.

Rgds / Ed