ILDA Compliant Projector Safety Board...

[Doc]

[buffo]

This is the way I do it in my projector:



Here's a link to the large version.

Adam

[mccarrot]

Wow perfect design Buffo. This is exactly what I was looking for.

I can use this perfect in my Stop over Ethernet design

I only think I will change it a little bit, because I would like to have seperate contol over the shutter with the scram button, and the keyswitch for the laser power.

Thank you very much for sharing!!!

[buffo]

No problem. It's been posted in my gallery for quite some time now.

It's always been my interpretation of the CDRH rules that the projector "start" must always be an operator-commanded function. That is, the projector must not start up under *any* circumstances, unless the operator has pressed a button to command it to start. (And then it must go through a start-up delay, which is not shown on my schematic above.)

The problem with a lot of projectors is that they only implement "commanded starts" following a "commanded stop". That is, if you hit the scram button (or kill switch, if you prefer), then the projector shuts down and you have to reset the button (or press a start button) to start the projector back up.

But what if the ILDA cable is unplugged from the projector? That breaks the interlock loop, so the projector shuts down. Ok... But what happens when you plug that cable back in? On a *lot* of projectors, everything will start right back up again, all without any operator action. I don't think that's safe, or legal. Thinking about that situation is what led me to this design.

Adam

[300EVIL]

Any updates on this project?

The groupbuy for scanfails is almost finished.

Well, I have been sort of following that thread. While I understand it has scanfail it looks like it has other functions and features i was planning on having as well. I was hoping to design something exactly like this with an Atmel based MC and LCD screen, but it appears it's already been done. I don't know if it's worth the time and effort to compete at this point. Along with my limited experience in programming and the time involved (which I no longer have) I think I've given up. Maybe it would make sense to design a simplified version that is not MC based like I originally envisioned. We'll see but I'll most likely can the project.
Thanks!
Adam

[mccarrot]

Hi Uber master guru Buffo

The EN 60825-1 is very clear about the interlock and the mains interruption

Your design is the solution for this.

As you can see the 2nd remote scram interlock does not need the manual reset.

The reason I want separate control of the shutter is that I can warm up the lasers with the shutter closed.

EN60825-1

4.5 Manual reset
Each Class 4 laser system shall incorporate a manual reset to enable resumption of accessible Class 4 laser radiation emission after interruption of emission caused by the use of the remote interlock connector or an interruption of longer than 5 s of electrical mains power.
NOTE Manufacturers may include a second interlock connector that does not require active action for starting emission, but it is not required for a product to have two connectors.

[buffo]

I've never read the European standard before, thanks for posting that excerpt.

The remote reset on the kill switch box is redundant, but I did that for convenience more than anything. It only added one more transistor to the design, so I figured it was worth it to be able to reset things from my chair rather than having to get up and walk to the projector.

As for the "warming up" of the lasers with the shutter closed, I also have that feature on my projector, and it is also not shown on the schematic above. What I did was to put a double-pole, single throw switch in the line leading to the shutter. This switch is after the main relay you see in the schematic, but before the shutter. It either connects the shutter to ground (which closes it, obviously), or to the shutter signal line coming out of the main relay.

This way, you still can't force the shutter open, but if all interlocks are satisfied and the projector is running, you can send an image to the projector and flip this toggle switch to manually close the shutter. That way the lasers (and scanners) are running, but there is no light output.

I even considered putting this switch on the remote box, but I found out that I really didn't need it. I don't have to warm my lasers up before a show. (Then again, my projector is only rated for ~550 mw.)

Adam

[mccarrot]

My green and especially blue need a few minutes to get at full power.

So for me I like to have the possibility to control the shutter from remote with the scram button.

I will work on my "stop over ethernet" design and let you know the final design to get your final thoughts.

Are you ok if I make some PCB's of your design for other forum members?

[Doc]

I've never read the European standard before, thanks for posting that excerpt.

The remote reset on the kill switch box is redundant, but I did that for convenience more than anything. It only added one more transistor to the design, so I figured it was worth it to be able to reset things from my chair rather than having to get up and walk to the projector.

As for the "warming up" of the lasers with the shutter closed, I also have that feature on my projector, and it is also not shown on the schematic above. What I did was to put a double-pole, single throw switch in the line leading to the shutter. This switch is after the main relay you see in the schematic, but before the shutter. It either connects the shutter to ground (which closes it, obviously), or to the shutter signal line coming out of the main relay.

This way, you still can't force the shutter open, but if all interlocks are satisfied and the projector is running, you can send an image to the projector and flip this toggle switch to manually close the shutter. That way the lasers (and scanners) are running, but there is no light output.

I even considered putting this switch on the remote box, but I found out that I really didn't need it. I don't have to warm my lasers up before a show. (Then again, my projector is only rated for ~550 mw.)

Adam

I believe that parts of the BS EN 60825 standard are being accepted by your CDRH now.

If you are interested Adam, I uploaded the entire document to the FTP "docs" directory a while back.

[colouredmirrorball]

Thank you Doc, that is a very useful documentation and I can use it well.
However, has anyone the Dutch version and would that person be so kind to upload it to the ftp? I would really appreciate that, reading 100+ pages in a foreign language with a lot of complicated terms is just a bit too much.