So, I recently picked up an IBM 4032-1 that was floating around on eBay for awhile . Never heard of this horn before, though just from taking it apart it looks like an IBM 4030 without the horn projector and maybe a different diaphragm(?). 110 VAC device, wired to a plug and supposedly functioning.
What perplexed me was that this horn came mounted to a metal box, of which I assumed it was just a some kind of odd mounting device for some kind of application. When I cracked the box open, to my surprise, I found a circuit wired to it. Even though my main interest in terms of fire alarms comes from these old AC systems, and maybe I’m just out of the loop, but I’ve never seen anything like this before. Granted, I don’t know too much about how these old systems were wired.
I haven’t plugged it in yet, but my best guess is that it’s some kind of coding circuit just looking at the schematic, though I’ve never seen or heard of a horn being directly coded outside of the panel or a coded pull.
In any case I thought it was interesting and wanted to share it.
