Creaky Old Award Winning Bastard Technologist Infinitus Excellentia Ion Laser Dominatus
Join Date
May 2007
Location
A lab with some dripping water on the floor.
Posts
9,902
Why you guys insist on doing everything the hard way I have no idea... A power cut, that's just awesome for the lasers lifetime.. Its even more awesome for the scanner amps, which do not like surges. IMHO Scanners should stay moving if possible to reduce inadvertent exposures... And you should have masking if the beams are too hot for audience scanning.
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Projector should support pins 11 and 17 anyways...
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See attached picture, about 20$ on Ebay for a relay array... Route 11 and 17 to the relay array, and you can remote the relay boards as they are current, not voltage driven devices..
Yes, They also make nice remote ILDA switches.. The Sainsmart boards have optoisolators, even better to prevent ground loops....
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Of course no one wants to do the CDRH's preferred spring loaded fail safe solenoid or actuator based shutter any more but me... Why you may ask? Well, the lasers stay up and stable, and I'm not trashing my galvos...
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My current design uses a 2.4 Ghz industrial "fail safe" radio system that drops the relays and grounds all RGB inputs if it looses sync or RF carrier from the master transmitter. Less then 90 milliseconds after estopping the transmitter, the remote relay boards drop the interlocks... Its not WIFI compatible, so it will ignore all other 2,4 Ghz signals at the venue.. The cool thing is all the slave RF boards retransmit any command to each other, acting as repeaters.. Its a mesh net, but if the slave cards loose the master, it shuts down, period. The slaves also look for the master's broadcast serial number, so if a second network using the same cards is in the venue, it will not open the shutters for anyone but the master transmitter card. These cards offer 156K bidirectional and simultaneous serial data, so a future variant will offer crew communications phones or text at the remotes. The hardwired ESTOPs are still wired back to the booth, but a remote ILDA Switch/Failsafe/Clearcom clone is darn useful at venues. Especially when aligning projectors alone.
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Steve
Last edited by mixedgas; 03-24-2016 at 08:34.
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...
Why you guys insist on doing everything the hard way I have no idea... A power cut, that's just awesome for the lasers lifetime.. Its even more awesome for the scanner amps, which do not like surges. IMHO Scanners should stay moving if possible to reduce inadvertent exposures... And you should have masking if the beams are too hot for audience scanning.
~
Projector should support pins 11 and 17 anyways...
~
See attached picture, about 20$ on Ebay for a relay array... Route 11 and 17 to the relay array, and you can remote the relay boards as they are current, not voltage driven devices..
Yes, They also make nice remote ILDA switches.. The Sainsmart boards have optoisolators, even better to prevent ground loops....
~
Of course no one wants to do the CDRH's preferred spring loaded fail safe solenoid or actuator based shutter any more but me... Why you may ask? Well, the lasers stay up and stable, and I'm not trashing my galvos...
~
~
Steve
Exactly. Pulling power from moving scanners can cause them to twitch and possibly park in a resting position that might be in the audience. This is where beam block is handy. But the reason people use power for estop.. is because its convenient and they dont have to run any additional cables. Using pins on the ilda cable works, if you are not using a FB4 or a network based solution that doesnt use ILDA cables.
Why you guys insist on doing everything the hard way I have no idea... A power cut, that's just awesome for the lasers lifetime.. Its even more awesome for the scanner amps, which do not like surges. IMHO Scanners should stay moving if possible to reduce inadvertent exposures... And you should have masking if the beams are too hot for audience scanning.
~
Projector should support pins 11 and 17 anyways...
~
See attached picture, about 20$ on Ebay for a relay array... Route 11 and 17 to the relay array, and you can remote the relay boards as they are current, not voltage driven devices..
Yes, They also make nice remote ILDA switches.. The Sainsmart boards have optoisolators, even better to prevent ground loops....
~
Of course no one wants to do the CDRH's preferred spring loaded fail safe solenoid or actuator based shutter any more but me... Why you may ask? Well, the lasers stay up and stable, and I'm not trashing my galvos...
~
My current design uses a 2.4 Ghz industrial "fail safe" radio system that drops the relays and grounds all RGB inputs if it looses sync or RF carrier from the master transmitter. Less then 90 milliseconds after estopping the transmitter, the remote relay boards drop the interlocks... Its not WIFI compatible, so it will ignore all other 2,4 Ghz signals at the venue.. The cool thing is all the slave RF boards retransmit any command to each other, acting as repeaters.. Its a mesh net, but if the slave cards loose the master, it shuts down, period. The slaves also look for the master's broadcast serial number, so if a second network using the same cards is in the venue, it will not open the shutters for anyone but the master transmitter card. These cards offer 156K bidirectional and simultaneous serial data, so a future variant will offer crew communications phones or text at the remotes. The hardwired ESTOPs are still wired back to the booth, but a remote ILDA Switch/Failsafe/Clearcom clone is darn useful at venues. Especially when aligning projectors alone.
~
Steve
Maybe it's because Murphy (from Murphy's law) is my best friend and I'm over cautious, but only grounding the RGB inputs to me does not sounds like a fail safe E-stop. What if a driver failes and the laser stays on with a grounded input?
I use solid state relays to cut the AC power to the laser PSU's and I keep the fans, galvo drivers powered all the time. I do use pin 4 and 17 to control the solid state relais.
Maybe it's because Murphy (from Murphy's law) is my best friend and I'm over cautious, but only grounding the RGB inputs to me does not sounds like a fail safe E-stop. What if a driver failes and the laser stays on with a grounded input?
I use solid state relays to cut the AC power to the laser PSU's and I keep the fans, galvo drivers powered all the time. I do use pin 4 and 17 to control the solid state relais.
I use Stanwax control boards. They crowbar the modulation signal to the lasers and disconnect the power to the laser PSUs. They work great and are very affordable in my opinion.
Creaky Old Award Winning Bastard Technologist Infinitus Excellentia Ion Laser Dominatus
Join Date
May 2007
Location
A lab with some dripping water on the floor.
Posts
9,902
[QUOTE=mccarrot;325316]Maybe it's because Murphy (from Murphy's law) is my best friend and I'm over cautious, but only grounding the RGB inputs to me does not sounds like a fail safe E-stop. What if a driver failes and the laser stays on with a grounded input?"
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~~(Spec, for the love of God, Fix this spacing issue!)
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I forgot to mention the connection to 11 and 17 on my RF box.. See my remarks about mechanical shutter on 11 and 17. The CDRH required mechanical shutter method is very failsafe. These days, CDRH tolerates some projectors without the mechanical shutter, based on the diode driver extinguishing.... But you have to have physical masking in place.
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~~
Steve
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...
I have just made a short video showing why killing power to the projector is a bad practice.
Obvioulsy it also promotes my product as a suitable alternative as well https://youtu.be/-syni6sHdNc
Rob
If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
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Laserists do it by the nanometre.
I have just made a short video showing why killing power to the projector is a bad practice.
Obvioulsy it also promotes my product as a suitable alternative as well https://youtu.be/-syni6sHdNc
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Originally Posted by mixedgas
stanwax
