Mitsubishi ML520G71...Red Holy Grail or Flashlight Fail ??

[danielbriggs]

The main pump laser here, is eight watt watt green mounted on a lunchbox sized, water cooled, aluminum thermal block. If the cooling water shuts down, I get 35 minutes at low power, and 15 minutes at full power, before the diode overtemp pops, and that is with two 35 amp diode array FAPs The hoses are 1/4 inch, and the flow rate is low, about two litres a minute. The channel in the block is 1/4 wide and maybe a 18" long loop. Just a milling cutter and a square loop, not even serpentine.

Sounds like a nice Verdi?
The cooling setup on those is elegantly simple.

[planters]

I water cool all my diodes, not to aggressively overdrive them, but because this provides a flexible ( in my case ) means of eliminating thermal issues from the projector. I do not think that with these relatively efficient, high power reds that overheating of the macroscopic components like the diode block is going to be the weak link in their maximum power levels. But testing on a controlled platform just removes a source of uncertainty.
A relative test of these two diodes to see if the increased price is justified by the increased power of the P73 should be done. I agree that testing multiples of each diode will provide more reliable information, but I don't think we have much information at all yet. It may not serve much purpose to drive each diode to death, but if there is a drop off in a diode's output at a consistent point ( by testing a few) then it would be interesting to run the diode at some level relative to that point for an extended period. Once we start putting these in projectors, I suspect that the power levels will begin to creep up until the diodes do start to show problems. From $49 to $110 is a pretty big jump. What if the more expensive diode only puts out say 10% more power?

[mixedgas]

Sounds like a nice Verdi?
The cooling setup on those is elegantly simple.

Its simply elegant. And it took me about a hour to repair it, even when it was badly corroded by a client using corrosive coolant.
Easily rebuildable.

I may be able to take pics tomorrow, we might have the block loose.

For those who do not know, Verdi's laser head is sealed. It sets on a massive, well machined, rectangular block of a aluminum. Four bolted toggles hold Verdi down onto the cooling block lid.
Under Verdi is two steel alignment balls on welded on removable pins. Closed holes in the Verdi head drop down over the steel balls. Thus when you set Verdi on her block, she is realigned with the system within 1% tolerance or better.

You can buy somthing similar here:

http://www.jergensinc.com/site/wsg_w...s/group_no=503



Steve

[andyf97]

My box of P73 diodes will arrive today for testing, so we should in one or two days be able to confirm the specs are ok on the 500mW diode.

I understand DTR will also have some too.

[danielbriggs]

Its simply elegant. And it took me about a hour to repair it, even when it was badly corroded by a client using corrosive coolant.
Easily rebuildable.

I may be able to take pics tomorrow, we might have the block loose.

For those who do not know, Verdi's laser head is sealed. It sets on a massive, well machined, rectangular block of a aluminum. Four bolted toggles hold Verdi down onto the cooling block lid.
Under Verdi is two steel alignment balls on welded on removable pins. Closed holes in the Verdi head drop down over the steel balls. Thus when you set Verdi on her block, she is realigned with the system within 1% tolerance or better.

You can buy somthing similar here:

http://www.jergensinc.com/site/wsg_w...s/group_no=503


Steve

Steve,
If you are ever stuck for spares and can not salvage the current one, drop me a line. I have a large box full of those; (although would be dreading the postage!)

[andyf97]

Check out the photos I just made of the 500mW version

http://www.photonlexicon.com/forums/...319#post230319

[dsli_jon]

A watercooled S/S projector would be verrry cool (no pun intended) A little pump motor in there and a little radiator and fan on the outside with glycol in tubing running thru all the heatsinks .. Be the envy of all..

Indeed.. Sorry for the 'small t-jack', here, but.. I think this is worth a quick 'side-carrot'.. ...Did ja ever see this 'lil pup?



RGB Lasersystems 4 Watt 'Whitelight', circa 2008-ish.. Don't think they 'make' them anymore - no real 'reason-to' - but.. saw one of these in-action in NYS - alwesome.. Took the wind right-out of a Purelights' lungs.. ~4.2W, but w/ zero 'losses' from a PCAOM - direct-analog blanking, of course.. Stable, tight-beam, bright.. closed-loop liquid-cooled...

..Wish they'd 'remake them' - yes, I know they have such 'all-in-one'-beasts, now - Sir Kit has got a wonderful 6W specimen but I mean, specifically, a 'closed-loop liquid-cooled' one - like you say - just somethin 'cool' about it - like 'Back to the Future'-type coolness... ..Plus, gr8 having an 'all-in-one, beam-only', like these were - ya know, for us 'krazy-old beam-table + scan-head' fans..

Anyhoo, carry-on.. - OP, I will shortly-nuke this little 'aside' once you've had the chance to 'enjoy / DL the pr0n' - I do-respect the topic, Sir!..

j

[polishedball]

So on the 71 what has been found the optimal current setting for continued use? All of my tests were don;t over the winter with an ambient of 60 degrees, today I fired my module up that was steady at 900mw (dual) and it dropped like a rock with an ambient of 80 air temp.

Is it true the p73's are more ambient friendly and hold better when over driven?

[Stoney3K]

Andy, I'm not suggesting its a cure-all, but cooling seems to be the weak link in a lot of projectors, and it has to be contributing to early diode die-off.

Steve

I always wondered why we never got to water cooled SS projectors in lieu of dusty, noisy air cooled units.

With the tools we have right here, it should be dead simple to design a projector that's cooled by standard PC water cooling components. I guess a simple 3x120mm or two 2x120mm radiator assemblies would give you more than enough capacity.

Major advantage: You can just TEC everything, slam it to an optical deck and cool the optical deck with a water cooling loop. The whole optical path can be sealed and dust-free, since it needs no air flow to begin with.

[planters]

Look at my posts; "Heavy Yellow", "20 Diode Modules Revisited". These custom water cooled systems work very well, have never leaked, are low cost and were easy to install. These were big systems, but PC based components would be very appropriate to typical projector heat loads and even easier to assemble. Diode mounting blocks cooled this way do not become even detectably warm.