E Stop Boxes (Amerikan FDA safety)

[lightlinked]

Whats the deal with this? Are you guys using these? It seems like a thing you should have with a pulsed laser or when you have something approaching double digit watts. How is yours connected? DB9 or something else like built into an umbilical to an external configuration device? I see alot of interlock bypass plugs.

Rules on the E-stop?
What kind of projector requires this?
When do you need one?
Where do you need one? Do you have to have EStop at FOH or where ever you are controlling the laser from? Can you just dangle the Estop within reach of a human or stage crew?

NON Americans - do you use external e-stops on your laser show lasers?

What if you have tilt sensors (mems accelerometer) to shut down laser if bumped?

[norty303]

Non US. Yes i use an eStop in order to comply with HSG95.
Usually with the laser operator but also able to have one on stage so stage manager can also shut down if deemed necessary.

[WookieBoy]

Non-U.S. as well here...
Ditto what Norty said.
Mine 'daisychain' from stage box so I can put as many as needed for Stage manger, rack engineer or who ever needs to have one as well as mine at FOH, but only mine will allow a re-start...

[norty303]

It seems like a thing you should have with a pulsed laser or when you have something approaching double digit watts.

Incidentally, why do you think they might only be required with lasers of this nature?
A 500mW laser is in the same 'class' of lasers as the others you have mentioned, so considered no less dangerous.

Anecdotally, I have never been in a situation where I've had to use an estop. I've had scenarios where I've had to kill the lasers (unnanounced stilt walkers at festivals are common ones), but in all of those situations its been quicker to simply blackout as its been under my hand, rather than reach for the estop.

[mixedgas]

Have found the Big Red Switch to be very useful in a stage environment. Especially with uncontrollable actresses who are the tribute band's girlfriends that don't want to listen about down-cones. Also very useful when obese female protestors carrying Chihuahuas show up to disrupt the show. (Remember that one, DSLI?) Even more useful when the now former stagehand climbs on your large beam table to adjust a lighting fixture. Both devices would have been useful when the very large, multiwatt, OPSL fell over in Europe.

Also very useful in clubs and for lasers in airspace applications. Good projectors support pins 11 and 17 (Interlock) on the Ilda Connector.

Would NOT want to do a public show without one. Moral of the story, The Keyswitch and the BRS have their uses in public environments. They came into being in the US when the early BRH actually went on tour with some early laserists to write the rules.. They are not some AMERIKA conspiracy to make your life hell. They are intended to protect YOU from people who do stupid, unpredictable, things.

Not everything runs off Pangolin's ESC key, and some times control cards will lock up.

Besides, master shutters let your DPSS Green stay warmed up, if you have an unstable one.

Steve

[andy_con]

(this isn't an offer to make anymore, just to show a possible way of doing it)

I made this for someone a little while ago, but of a one off project type thing

4 ilda inputs on one side and 4 ilda outputs on the other, estop in the middle and add 5v. job done

[lightlinked]

so do you have this with you at the location you control from (FOH or by the lighting console) or can you have it just at an accessible location (next to laser)?
is that okay to have it done over ilda vs a separate interlock/connection? ( the DB9 connector on alot of projectors)

[mixedgas]

If done correctly the loop can be quite long, on the order of hundreds of feet. If need be, a 12$ wall wart power supply and a small relay can extend the loop for thousands of feet or create multiple loops. A dozen relay contacts give you a dozen loops and so forth. So you can even have multiple locations of BRS hundreds of feet apart. Yes, even the DB9 can go a long way.

For a friend, I have created a fail safe RF loop, using a surplus industrial 2.4 Ghz module that has a failsafe "Watchdog" TTL output that opens if the master transmitter drops out. The attached relay provides a valid interlock unless the RF drops out for longer then 100 mS. The master and slave units constantly broadcast their serial number as part of the spread spectrum connection preamble, so normal WIFI won't cause a false event.

As long as the loop is designed to "Fail Safe" you can do many, many things with it.

The TEST the government uses is to remove the interlock plug suddenly. If the laser drops out very fast, you pass. It is best if you have to manually reset the loop after a fault. For a very high power event you want the manual reset so your sure your computer has restarted etc. It is rare, but some show control systems do not reset their outputs if the computer crashes. In fact, a few older older generations of Pangolin with the QM32 would continue to run the show perfectly during a Windows Crash.

It is good practice to electrically ensure an un-commanded laser beam never leaves your projector. LDs and Safety officers do not want to see unwanted beams.



Steve

[norty303]

Yes you can implement the eStop however you like. I run mine over the interlock loop (4 and 17) of the ILDA cable. I worked out very early that the least cable the better. Actually, I run my eStop over cat5 from wherever I'm controlling from to the stage box, then the stage box handles the multiple interlocks by way of relays.
I also have some pass thru style estops like Jon's that go inline with the ilda cable.

[White-Light]

(this isn't an offer to make anymore, just to show a possible way of doing it)

I made this for someone a little while ago, but of a one off project type thing

4 ilda inputs on one side and 4 ilda outputs on the other, estop in the middle and add 5v. job done

Very nice work Andy.