Film-Tech Forum ARCHIVE: A universal kill switch

This is topic A universal kill switch in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Peter Mork (Member # 1336) on 10-23-2005, 01:51 PM:

Today, some kid pulled a fire alarm in the lobby and shut the whole place down for twenty minutes. This happens a lot around here - either that or someone burns the popcorn and triggers the alarm. I'd say five or six times a year we get blasted by those sirens and blinking lights.

I work in a six screen house with three separate booths on three floors. When an alarm goes off, I have to run to each projector and shut it off manually. Of course, I'd rather not have to do this, especially if someday there really is a fire.

Can anyone recommend a system to kill all projectors simultaneously from any booth - ideally one that won't require running new wires: perhaps radio-controlled? It would make my life easier!

Thanks

Posted by Brad Allen (Member # 470) on 10-23-2005, 02:31 PM:

It would be fairly simple and inexpensive with 3 12v relays and 3 momentary contact push buttons to wire up a remote shut down.

Posted by Pete Naples (Member # 761) on 10-23-2005, 03:53 PM:

Did one not so long ago. Very similar set up.

One high current relay breaks the projector motor, rectifier control circuit, and 'RUN' circuit of the Westrex tower.
Another smaller relay raises the house lights, and mutes the sound.

All done from one big red push button in the operators 'office'.

Posted by John Walsh (Member # 168) on 10-23-2005, 05:13 PM:

Some automations have that feature already built-in. What kind of automation? Not the radio controlled part, but at least with wires. Look at those "X-10" wireless remote controls (www.x10.com) They are cheap and work fairly well, although I wouldn't trust my life with one.

Most places I know of require the projectors all shut down by law; Mass has very tough fire safety-related laws, so I am a little surprised you don't have this set-up.

Posted by Steve Guttag (Member # 268) on 10-23-2005, 05:27 PM:

Depending on your automation system...some offer an emergency stop or "Fire Stop" on the status panels (Strong's CNA series for instance...find any of those panels and have the fire alarm system provide a dry contact that closes when the alarm goes off...it will shut down the plex).

For automations that are not too sophisticated, we have the fire alarm company provide a "Dry contact via relay" and just wire across the "failsafe" so that the automation presumes that it is a film break.

However...a "Fire Stop" is normally a bit more elaborate than a standard film break...that is, the video/slide projector should not come on and the sound system should go to MUTE so as never to compete with the life saftey system.

Posted by Steve Scott (Member # 630) on 10-24-2005, 12:50 AM:

Indeed, Steve and John are right... Fire alarm test day is always a great day in any new construction... [Embarrassed]

Posted by Peter Mork (Member # 1336) on 10-24-2005, 12:56 AM:

quote: John Walsh
Most places I know of require the projectors all shut down by law; Mass has very tough fire safety-related laws, so I am a little surprised you don't have this set-up.

Funny, the fire guys never mention this when they show up.

Posted by Scott Norwood (Member # 30) on 10-24-2005, 08:22 AM:

We have something like this in Waltham. It shuts down the automations (TA-10) when the fire alarm goes off. I don't know if it mutes the sound or switches back to non-sync. We don't have slide projectors there, so that's not an issue. I've never personally been there when the fire alarm has been activated, but apparently the system works. There's no "kill switch" as such, however, unless you consider a fire alarm pull box to be a kill switch.