Scanner endurance.

[The_Doctor]

...AGC current source...

Automatic gain control? Just making sure I don't miss something important... Is this the thing that drivers do to make the scanned image smaller than expected if they think the galvos are in danger of being overdriven?

With the Widemoves I judged the overdrive partly by watching the circle in the ILDA pattern, and especially the jitter in the (usually blanked) bight that connects from the small square to begin the circle. There was also a distinctly dirty edge to the noise they make in a silent room when pushed to that point! That and the deterioration in repeated positional accuracy told me when to back off.

It will help me a lot to know what to look for when using the Cambridge system. While an AGC might protect better than I alone can, it might also mask an onset that I'd otherwise detect.


Jem, thanks, a clear image of things helps. I read about that power demand, could be enough to heat a small room. Something over 240W per axis I read somewhere. I'm ok with thermal design though, enough to solve the need, same for power supply. Won't be an overnight thing though. (And it was at least a year since I bought the Widemoves before I'd mounted them and run them having enough support to make it meaningful). Maybe I should keep the small platform I made just because it IS small. Did you go for very narrow beams for high visibility in air and fine graphics? That's pretty much what I want to do, but to explore image generation with light the way analog synthesisers can make sounds. 'Abstracts', in a way, but a more directed thing, ideally something that can become a live performance. I have a very synaesthesiastic take on how lasers might work with sound. This is why I want endurance. My Mackie HR-824 speakers seem to last forever and I'm hoping that CT6215's, if driven at modest levels, will run for many tens of thousands of hours without need of maintenance. I hope that isn't an impossible thing to ask of them, anyway...

[mixedgas]

AGC in this case modifies the position sensor LED current to improve linearity based on the instantaneous sensor positioning. You are thinking of power limiting, which is a different circuit.



Steve

[The_Doctor]

AGC in this case modifies the position sensor LED current to improve linearity based on the instantaneous sensor positioning. You are thinking of power limiting, which is a different circuit.



Steve

Ok. Thanks. And now for a deeply technical question: Why is water dripping on the floor of your lab?

[Jem]

Did you go for very narrow beams for high visibility in air and fine graphics?

Pretty much, yes. I have this unhealthy obsession with abstracts, not so much with graphics. And, as you state, very fine low divergence beams tend to give high visibility for overhead beams. The overall balanced white power of my mini projector is just under 1 watt, but it appears much brighter when viewing the beams.

[mixedgas]

Because I work on water cooled lasers. Either during install or operation, there are always some drips, it is the nature of the beast.

Despite what you might think, many modern lasers are still water cooled. This will be the case for quite some time.


Steve

[The_Doctor]

Because I work on water cooled lasers. Either during install or operation, there are always some drips, it is the nature of the beast.

Despite what you might think, many modern lasers are still water cooled. This will be the case for quite some time.


Steve

Doesn't surprise me at all. Even a little diode laser can benefit from water cooling, I experimented with that for a while. I just thought your location statement was casting whimsical aspersions at the general fixtures and fittings.

Incidentally, given the special attributes of water, and its very high specific heat capacity, never mind 'quite some time', water cooling will be vital in many things unless the laws of our universe substantially change.. I also note that some guy tested a load of thermal greases, and found little difference in any, silver loaded or otherwise, but a smear of water beat the lot, and if the stuff didn't dry out so easily there'd never have been a need to invent 'Arctic Silver'.


Jem, did you post any details on that laser? I'm interested, it sounds like you have the right idea for my aims too. And there is nothing unhealthy about an obsession with abstracts... Seriously, which is preferable, a mind blowing display of Tangerine Dream-like synaesthesia, or 16 grand's worth of kit making Donald Duck waddle erratically and repeatedly across a screen of wall or water? I rest my case. I like Donald Duck when in the mood, but there are limits..

[Jem]

Jem, did you post any details on that laser? I'm interested, it sounds like you have the right idea for my aims too. And there is nothing unhealthy about an obsession with abstracts... Seriously, which is preferable, a mind blowing display of Tangerine Dream-like synaesthesia, or 16 grand's worth of kit making Donald Duck waddle erratically and repeatedly across a screen of wall or water? I rest my case. I like Donald Duck when in the mood, but there are limits..

Lol, now you're talking... Tangerine Dream Vs. Donald Duck... HeHe

TD are one of my favourite bands. You'd have enjoyed the recent ShowLEM, we played TD and Pink Floyd all the Sunday morning whilst playing with beams and abstracts... Chilled out does not even begin to describe it

As for the projector i'll drop you a PM.

[swamidog]

i can relate.. i'm also firmly in the "love for abstracts" camp.

Pretty much, yes. I have this unhealthy obsession with abstracts, not so much with graphics. And, as you state, very fine low divergence beams tend to give high visibility for overhead beams. The overall balanced white power of my mini projector is just under 1 watt, but it appears much brighter when viewing the beams.

[Jem]

Hey Doc

You've got your preferences set to not allow private messages. Can you either change it or drop me a PM with your email as i'd like to tell you more.

Cheers

Jem

[The_Doctor]

Sorted.. I forgot that, a hangover from when I left last time. While I fixed it I discovered 'Black & 635'.