What would this be for? Something at someone's desk so they could spy on them?
Or is it something like a door phone where they need something triggered when someone at the door goes off hook?
Ralph
Frustratingly, I have no idea. Part of them pretending they're clandestine, is that they never want to explain themselves. Their tech supervisor called me because he wasn't to do
something. He is unable or unwilling to tell me what he's trying to accomplish, even in general terms. I asked, "Is your goal interacting with a system, or live interaction with someone in the room?" and he wasn't able to answer...
The only thing he said was that he needed a relay that would open and close when the handset was picked up, because he had figured out a way to do whatever the heck he wanted to do if I could provide that.
After I posted this, I went back to him to clarify if he specifically needed a relay for some reason, or if he really just needed a circuit that opened and closed. He confirmed that an opening and closing circuit would do the job, so I pointed him to the same kind of micro-switches that cheap 3D printers use for end-stops, and suggested affixing one of those to the top of the phone where the handset hangs over. They activation pressure is very low, so he should be able to find a mounting height where it reliable closes the switch when the handset is on the base without interfering with the actual hook switch. Effective, he's going to hot-glue an external hook switch to the phones, so I guess we're good.