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

[DTR]

I am clearing out the P71's to get funds to stock a good quantity of the P73's. $46 for one down to 10 for $400. If anyone wants to grab them.

[andyf97]

I am clearing out the P71's to get funds to stock a good quantity of the P73's. 10 for $420 or 20 for $800. If anyone wants to grab them.

That's good after I just paid more )

How many you have?

[planters]

The first question is what will be the price for the P73's?

The next question is do we have a relative output power of the P73's vs the G71's?

DTR,
Did you graph the output as you ramped the current up so the slope can be estimated. Did you test a P73 yet? What happened to the wavelength when you found it to become less stable?

It seems to me that unless the output power begins to approach double the output of a P71 the large near field and practical scan mirrors will still mean it will either be a dual or a quad rather than a dual instead of a quad and the associated optics, mounts etc will be unchanged.

[mixedgas]

Kiyoucan,
You send me one for test in a block and I'll run it on a 17.6'C glycol chiller loop all day and all night for months.

An approximation of Arhenius' law says reaction rates double roughly every 10'c. Its also applied to semiconductors.

Steve

[steve-o]

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 .. Maybe something like this.. (I pulled my pc cpu heatsink last weekend to replace the old hardened goose-grease) ..

[DTR]

That's good after I just paid more )

How many you have?

Yea I am pretty much giving away some stock on large quantities to get back some funds I laid out for the 73's.
I have a pretty good stock of the 71's as I really did not expect that they would keep their date this time for the 73's. Go figure. It actually felt like I cleared out enough of there stock of 71's that they could now release the 73's.

The first question is what will be the price for the P73's?

The next question is do we have a relative output power of the P73's vs the G71's?

DTR,
Did you graph the output as you ramped the current up so the slope can be estimated. Did you test a P73 yet? What happened to the wavelength when you found it to become less stable?

It seems to me that unless the output power begins to approach double the output of a P71 the large near field and practical scan mirrors will still mean it will either be a dual or a quad rather than a dual instead of a quad and the associated optics, mounts etc will be unchanged.

I will have to dig up the thread. There is one over @ the other place on wavelength vs current on the 71's. I have not tested the 73's yet but another member over there did do some tests on them. Here is his thread.
http://laserpointerforums.com/f50/fi...ode-69702.html

[planters]

Steve,

I'll take you up on this. I just received some diode mounts and the 2mm lenses from Dave. I also have a G71 diode. If someone will supply you a P73 diode, then I'll ship you two mounts and lenses and one diode and you can set up a side by side longevity test of the two diodes at a fixed temp. Question, both at the same setting, vs both at the same over spec current, vs both at 80% of dimming current( to be determined), etc?

[mixedgas]

Onesies are really not a good sample group, But there is a chiller running 24-7 with excess capacity. Next to it is a really nice spectrometer.
My boss is always interested in new laser technology, and while red is not his thing, I'm sure I can get permission.

Dispite what most people try to achive here without active cooling, every scientific laser over a watt in this building I work in, and there are LOTS of them
hang off chillers or tap water. That "water dripping on the floor" thing in my sig is still true, and will be for a long time. Even the compact diode pumped stuff has water to air exchangers in 3 unit tall 19" rack mount boxes. The water hose size may only be 3.2 mm or 1/8th inch inside, but its there.

The pumps are quiet, and quiet inexpensive.

Water/glycol mixes get you isothermal, isofast, and also isostable. Isoget it? Isothermal is good.

Only thing air cooled in my bosses lab are the henes and my IR diode alignment laser.

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.

The 35 watt, diode pumped, Qswitched green, gets a freon based chiller about the size of a filing cabinet drawer.
The laser itself, is about one foot sqaure and six inches tall, but it gets half inch hoses and a two GPM flow rate.
You could easily get the whole laser SYSTEM into the back of a small SUV or back seat of a 4 door car.

So water has not left, it has just gotten better.

I Gotta go, I have a 4 character LED display on some one else's optical table showing a alternating "LOW" and "2.0" right now. Need to add some water, about a litre every three months. That water evaporates out the tiny air vent on the heat exchanger tank. Why? Even when the laser is not running, the pump is running, and the flow heats the water about 5 degrees above ambient when the cooling coil is bypassed in standby.

Steve

[andyf97]

Interesting somebody over at the other place was getting 1.1W from the P73, then it started to drop off after around 50 seconds. I guess that was due to heat. Thing is who want to drive them to death, it's just greed. If they run happy at 800-900mW and last longer it is enough. From his photos there are only two bond wires each side, so a bit of care will need to be taken. Certainly when I get a few in the hand I will do a kill test on one, I already opened up a topic for the test results.

Cooling could certainly help but not to be used to drive them crazy over power, I think 1.1 will be the max so 1w could be a safe area if cooled well.

Like always we have to see along with the emiter.

[mixedgas]

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