Comment by ssl-3
20 hours ago
I've read through your story and I think you're on the right track with what you're doing.
But, re: alarms, I'd like to add a suggestion: Indoor sirens. They can be intolerably, painfully loud for not very much money (because piezos are cheap and square waves are easy). Using a small, random mixture of them can let them beat at different frequencies and periods, which can make them very unpleasant to behold even with hearing protection.
If you feel like being clever, you can even run them with a local battery that activates when they're disconnected. If you feel like being extra-clever, you can make them activate when they don't have the correct termination resistance at the far end of the line, or exactly the correct voltage: This way, whether the wire goes open or short, the sirens activate.
Super-extra bonus points for using a combination of methods. Any time that a thief spends figuring this out is time they aren't carrying stuff out.
And if that still seems incomplete, then: Fill the shop with smoke. They can't function when they can't even see their hand in front of their face. https://www.youtube.com/watch?v=RPgcysyFUiI
This seems like a good set of ideas if you can guarantee that you'll never have false alarms. I've had too many birds in warehouses and employees forgetting their codes to feel comfortable going full-hell-interior on alarm.
Birds? Yeah, perhaps. We didn't have any trouble with false alarms that I recall at one shop I worked at with a (relatively small, alarmed) warehouse space where the overhead door was usually open during warm days. I can see it happening, but the false alarms would happen regardless of the intensity of interior alarms.
And the system should not be armed when desirable people are inside, so that problem seems like it is for the birds.
When employees forget their codes and trip the alarm when they're the first ones into the shop at whatever time, they can just go outside to escape the hellish indoor torment. Not perfect, but not so bad either when the goal is to keep people out. :)
Perhaps the smoke should have a harder trigger than the noise, though, if for no other reason than it's a consumable that eventually needs to be fed more money every time it is activated.