Electronic Alarms and Home Security Devices - Strobe and Siren Device 120 volts

I have a 3 family house that has interconnected smoke detectors, and the fire marshal has told me that I should install a strobe siren device outside and connect it to the smoke detector in the hallway.I have looked all over the place and all the strobe/sirens are low voltage. Nothing I can connect to the existing system. Any suggestions or advice is appreciated.
Thank you,

Ive yet to see a house that has that set up. I have seen though, relays that tie into the 120v smokes that will trip home security alarms. Maybe go this route and see if you can find this 120v smoke relay and hook it up to a 12v power supply to trigger your 12v siren/strobe. Im not sure were you get this relay, though. I do know they exist cause ive seen them work on jobsites.

That's a rather strange suggestion. Standard residential interconnect smokes don't really lend themselves to such configurations.

Most brands, for example, makes a strobe that works with it's interconnect smokes:
http://www.kidde.com/utcfs/ws-384/Assets/SL177i%20Sheets.pdf

177 candela strobe unit connects to certain hardwired BRK/First Alert smoke and CO alarms for the hearing impaired. (http://www.firstalert.com/safety_products_item.php?pid=103)

110v Horn/strobes are made by companies like Cooper Wheelock. http://www.wheelockinc.com/mediacenter/specs/S2000.pdf

The trick with using something like this, is you would need a relay that is triggered by the interconnect to activate the horn/strobe.



Basically, this is something very easy to do with alarm system powered smokes, and very difficult to do with interconnected hardwire smokes.