I know this used to exist because I used it before I just can't remember who made it. Basically I have two IR systems that I want to feed to a single source. There used to be a y adapter or something like that would allow you to hook up two IR systems to 1 IR emitter, with some kind of protection built in so those signal would only go to the emitter. It had a diode inline or something like that. Maybe it was an emitter that had this built in, I just don't recall. Any help you can give would be appreciated.