Are you sure the projector won't do this by itself? I remember working on a projo a few years ago that would leave the 12v trigger hot until the cool down cycle was complete. Unfortunately I can't remember what projector it was...

You need to think of what will happen when things fail, because they will fail. If the lift gives you the ability to get to the projector when the projector is working properly, then any projector failure will lock the projector up inside the ceiling. That's poor design. Use some external source for the trigger, or at least bring all trigger circuitry out to some place where you can lower the lift a) without the projector being on and b)without running external voltage into the projector's trigger port.

In the few projectors where I've messed with their trigger outputs, those outputs did not supply enough current to trigger a relay, so additional circuitry was necessary just to get a real trigger signal. So I've handled it other ways, as described.



Pat, I'd be happy to design something for you, but for some reason I just don't feel like giving away design time this week. Sorry. Email or PM me and we can work something out.

just did an Epson 8350, $1,350 with 12V trigger out.

Thanks Ernie, I'm not looking for free design just a product recommendation for the trigger delay. I do have other ways to trigger the projector (from the A/V receiver or IP Network Gateway) and will likely switch from the projector trigger when I make this change. Even when the lift is retracted into the ceiling the panel is removable for access but your point is valid.

The Calrad piece is quite reasonable. If you're not a dealer, contact me and I'll get one for you, as I'm a dealer.