Bob. If your projection screen will raise/lower with a contact closure, and X-10 Universal module should work for you. A Universal model receives an X-10 command (e.g. from the Pronto via an IR543 (aka 4040))and then closes a relay that is connected to the two screw terminals on the module. You can set the module to provide momentary contact closure (2 seconds) or set it for continuous contact closure. If it is set for continuous closure, you would have to send it an X-10 off signal to open the contacts. The contacts are rated for up to 5A at 24 VDC, or 15A at 120 VAC if properly insulated.
RCI Automation[Link: ourworld.compuserve.com]