Mitsubishi P73

[CDBEAM]

Terrawatt Lab staff has been experimenting with the P73. The set-up used the 6X cylindrical lenses from the Kiyoucan GB. The nearfield was approx 4.2mm, the farfield was 9.5mm. This delivers a divergence of 1.1mRad at 4.5M (15’). This is at par with the G71 results. Whatever the emitter geometry is…the results are good for beam shows and likely graphics! See pics comparing the P73 vs. a DPSS 532 and the G71 vs. a DPSS 532.

NOW, with the trail cutting work of Mr.Planters( See original Grail thread;Post #1257and # 1259 ) and Polishedball…the use of a simple TE+Radiator+fan cooling this LD down is looking to supercharge the slope efficiency. 1W at the rated max of 800mA looks to be within reach!!! ???.

Now on to 2X or 4X this Red power house. I feel this is the new “Red Grail “. We were fortunate that the previous work done on the G71 was the foundation for progress on the P73. Thanx to ALL. Our hobby moves forward. BEAM

[steve-o]

Amen to that. Glad we didnt have to start all over again. Lookin' good mr B

[planters]

CDBEAM,

This may be a little obsessive, but the P73 appears a little "redder". This is probably an effect of the photography, but do you have any means of comparing the emission wavelength? Also are both diodes at similar PO levels?

Oh...and thanks.

[steve-o]

Interesting question MrPlanters. Here are some comparison photos from G71 and P73 done in my junked-up "Lab" :
(done with the same camera, exact same settings both photos)
had smoke in the air, .. bottom one is different angle and possibly reflecting off of a different surface.. pooks "pink-er" to me .. dunno ..
I couldn't get the size right so they'd be exactly the same ..
Both cranking out over 1/2 Watt .

G71:



P73:

[DTR]

The smoke being used in the second shot looks a lot thicker. May be skewing the comparison.

[steve-o]

Lol yeh it was a big fatty ..

[CDBEAM]

For my comparison pics, the P73 was at 610mW....and the G71 was at 525 mW....Both the G71 and the P73 were driven at 725 mA. My eye sez they are at the same line !!! I have no equiptment to do a wavelength analysis.....(mmm...THAT toy is also on the Christmas List !!! haha). Possibly the camera reacted slightly differently and had more red saturation with the P73 ??? Dunno ??? But they were the same colour !!! A perfect shade of RED....Now....onward to put one " On Ice "...BEAM

[steve-o]

On Ice, yes! Please post progress notes MrBeam! I'm going to try that myself. Do you have your TECs now, or are you waiting for the big brown truck to arrive ?

[CDBEAM]

No...I will go with the units Planters suggested...about 47 Watts @ 5A. Planters, after all, he has a huge amount of experience putting the " Big Chill " on LD's !!! He notes NO controller is needed ... if layed out right...condensation is not a problem !!! That would be good, keep the design more streamlined and lower cost....but....if a controller is required...Polishedball has a nice little unit located !!! BEAM

[polishedball]

condensation is not a problem !!!

How do you account for ambient temperature shifts? My projector operates anywhere from 60 degree weather to 95degree. There can't be a single set point no controller for all circumstances can there? If so heck i'll just let em fly but I have scene the 168W units destroy computer motherboards when running wide open.