Safety-concern with the "Shutter" on LS-Pluto IIs / Venus... and a DIY solution...

[swamidog]

More than once I've seen a Chinese projector blast a momentary (split-second) full power beam out the front when a) ILDA cable is disconnected while unit is powered on, and b) when power to the unit is switched off. Presumably, a mechanical shutter would prevent such emission.

pangolin's qm.net *always* shoots a static beam during power up/down (this is crazy to me), but what's the difference between remembering to open/close the shutter vs. remembering to turn the projector on after the qm.net is powered up and off before the qm.net is powered down?

none of my projectors do a hot beam on power on, but i can see a shutter being necessary if the projector does.

[hitekvoop]

There's no remembering to open/close a shutter, it's keyed off the interlock signal and spring loaded. Closed by default.

Am I misunderstanding your question?

[swamidog]

There's no remembering to open/close a shutter, it's keyed off the interlock signal and spring loaded. Closed by default.

Am I misunderstanding your question?

ok. that makes more sense. if it's keyed off the interlock signal and the dac/software is smart enough to handle it...

a lot of the projectors i've seen don't do that. they just have a key switch to open/close the shutter.

[dsli_jon]

...they just have a key switch to open/close the shutter.

..And that's - actually - a better way to do it.. Rationale being, with a by-default spring-closed hard-shutter, it doesn't matter if an AC-transient causes a 5V spike thru modulation-lines, or if that horrible-idea DMX-board you shouldn't have in your pj hiccups and spits out a beam - a key-sw / Operator-controlled hard-shutter is a *guarantee* that the Pj is not gonna spit out photons, till you're 210% sure all is 'safe' and ready for firing...

..and, imho, the 'best way', is to have 'both' - relay-gated control of yer shutter via software, tied-thru Interlock loop / E-Stop, etc, but *that* is gated by a keysw... Which only You, the über-responsible Operator controls.. ...Ya know, great for when you've gotta go refill yer tequila-flask, and you don't wanna risk the 'DJ's GF' being able to kick-out photons out of yer 50W RGB off yer APC-40 whilst yer away.

...It's just - again, imho - a really-great, cheap / easy to integrate, and Totally-CYA 'insurance policy', and they turn the CDRH into putty in your hands.. Plus, if you really read the current Regs / *what sections* of the IEC standards they said laser-products could be more 'in-harmony with', it does not specifically negate thier spec'd-need for a shutter (..or an emission indicator, for that matter..) because they've basically said "Demonstration Laser Products" (..and, yes, they 'define' PJs, as-such..) are exempt from any 'IEC-standards-based interpretations' / relaxing of the requirements..

..Read here: http://www.fda.gov/MedicalDevices/De.../ucm094361.htm ... see under Section 2, "Guidance" (..and just ignore thier typo Lol..) for what they consider 'exempt from any IEC-conformance' (...which does-not automatically nuke shutters, etc, anyway..)... So..

..in the end, shutters aren't just 'the law'.. they're a good idea!..

.02
j

[Laserguy1]

OMG, LOL... Or your video guy next to you thinking he is a laserist while you catch some fresh air!!

[swamidog]

i've been talking to the ILDA folks about this, due to unrelated by relevant.

they like to see a shutter controlled by +5v on ilda pin 13 *and* an interlock loop that's activated by ilda pins 4 and 17 shorting.

this is a trivial bit of engineering.

[dsli_jon]

..this is a trivial bit of engineering.

Indeed..

...Or, sure.. just get a 'Stanwax boardie'.. ..But, point-being, you *can* 'DIY-it', it's not that hard.. See note, top-left, about adding a 'second SSR for Mech shutter'.. Of course, you would only-use +12V DC to 'drive' the Ledex shown in this thread, (..not this 24V, unless you expressly use a 24V coil-one..), but.. you can still 'gate' off this circuit.. Note, too, that this does not detail a 'keysw lockout' for the shutter, but, as you say, 'trivial engineering'..

..Perhaps when I get some time in 2019 I can draw-up that as a 'DIY-diag', also.. Will-post, if/when..
j

[swamidog]

any objections if i send this to lightspace?

it would make their projectors safer and easier to variance in the US and everybody wins when that happens.

Indeed..

...Or, sure.. just get a 'Stanwax boardie'.. ..But, point-being, you *can* 'DIY-it', it's not that hard.. See note, top-left, about adding a 'second SSR for Mech shutter'.. Of course, you would only-use +12V DC to 'drive' the Ledex shown in this thread, (..not this 24V, unless you expressly use a 24V coil-one..), but.. you can still 'gate' off this circuit.. Note, too, that this does not detail a 'keysw lockout' for the shutter, but, as you say, 'trivial engineering'..

..Perhaps when I get some time in 2019 I can draw-up that as a 'DIY-diag', also.. Will-post, if/when..
j

[dsli_jon]

any objections if...

Dele! (..espanish for Go! ..but the 'Omron relay' used in this design (..this was for the manual-reset I-lock circuit in DSLS's 40W KTP-jectors..) is kinda 'big and honkin': The Relay was Omron MY4N-DC24, and the 'socket' (screw-terminals make it easy to bus the other lines-in..) is Omron PYF14A-N, but, I am sure they can Google-up those data-sheets, and find / make an 'equivalent', quite easily..

...Again, tho, this exact-diagram does-not show / detail the 'Mech shutter' part of the circuit, but.. It's really quite a 'kindred design'.. just don't really need to dupe the 'manual-reset' aspects of this circuit, since, well.. duh... ..but, I'm sure there are 'circuit-masters' out there (ie: Rob Stanley.. that could spiff this whole thing up - including an SSR-gated Mech-shutter 'sidecar' - better than I can.. I'm a pretty-clunky circuit-designer... They work / are-solid, but.. Not particularly 'elegant'.. Which is fine.. Everyone brings something different to the party..

ciao
j