445nm been running all day at almost 1.1W

flecom said:

yes but if they are reported to be ok at 80 deg C you will be unable to physically hold the pointer before you reach critical temperatures

that being said, do you really need >1W in a pointer?

1W of laser light is pretty hazardous, even reflected power from shiny objects could pose a vision hazard... I know its been said a million times on here, and I really don't want to preach, but seriously guys think about what your playing with before you turn them up to 11

even I personally would not feel comfortable waving around a 1W pointer and I was just working on my q-switched laserscope earlier (you want to see a laser light anything on fire? this is it lol... but she needs a new KTP )

Click to expand...

80 degs C? Hmmm... IDK about that.

Either way the batteries and driver will not survive 80 degs C. In fact since the Flexdrives and Microboosts usually aren't hestsinked you're more likely to burn them out before the diode. 90% efficiency isn't enough when the diode is eating up 3.5 watts.

I agree with you, but technically speaking 100mW is even enough to blind you. So it's like comparing falling from 50ft to falling from 300ft, either way you're dead/blind.

-Tony

Xplorer877 said:

I agree with you, but technically speaking 100mW is even enough to blind you. So it's like comparing falling from 50ft to falling from 300ft, either way you're dead/blind.

Click to expand...

yes but an object reflecting 10% of 100mW is 10mW into the eye... an object reflecting 10% of 1000mW is 100mW into the eye

and if you want to just your comparison you at least have a better chance of surviving a 50ft fall than a 300ft fall...


anyway, point being, these diodes seem to be extremely (surprisingly) robust

Tech_Junkie said:

Did aliens drop this diode from the sky, or what?

Click to expand...

:crackup:

I can't wait to see what mine can do.

Me too. Mines still in the mail from Italy. 140, 1.4A. I'll throw it in a pointer to show my friends, then its going in a ray gun.

Quick question. Can I use a TEC to keep it at 60C? Should I use a driver, or will a pot work?

I guess I'm not so surprised. I understand how AMAZING this is in relation to other diode duty cycles and life spans.

OTOH... this diode was specifically designed for televisions and projectors. Appliances which are used for hours or even days at a time. If it didn't have such a tremendous duty cycle, the electronics mfg's would never have released any products using it.

Tech_Junkie said:

Me too. Mines still in the mail from Italy. 140, 1.4A. I'll throw it in a pointer to show my friends, then its going in a ray gun.

Quick question. Can I use a TEC to keep it at 60C? Should I use a driver, or will a pot work?

Click to expand...

If I were aiming for 60*C I wouldn't bother with one. I would think a heatsink system big enough to to cool the diode plus the extra heat from the TEC would probably keep the diode well under 60*C on its own without the TEC.

I've ran the diode for 16 hours each weekend for 4 weekends 64 hours at 1.2W and no degredation so far.

I would be incredibly interested if something like the kryton beast eventuated and featured active cooling or an integrated TEC

now that would be decent

spaceman_hux said:

I would be incredibly interested if something like the kryton beast eventuated and featured active cooling or an integrated TEC

now that would be decent

Click to expand...

I suspect that there is no TEC efficent enough ..... and it's just a problem of physic laws .....

I mean, a TEC does not produce "cold", it just transfer the heat from the "cold" to the "hot" side, also generating heat in the process itself ..... then you need to take away the heat from the "hot" surface (if you don't do it, the TEC plate, after a certain time, start to heat both the surfaces, and can reach a temperature high enough for burn the junctions or desolder them, destroying itself.

Also, there's a limit to the quantity of heat tha the TEC plate can transfer (is usually indicated as "power", in Watt) ..... this mean, as example, that a TEC rated for 50W, can efficently transfer a maximum thermal power of 50W, not more.

Now, just wondering ..... if you find a TEC small enough for be used in a handheld host, it will be, probably, a 6x6mm, or a 8x8mm ..... and can probably work around 1V at 2A, and transfer 1W or few more ..... plus, ofcourse, the 2W of heat generated from the plate for transfer the 1W of heat from the "cold" to the "hot" face (this, BTW, mean that for transfer 1W of heat from the device to the heat dissipator, it have to dissipate to the ambient 3W of heat ) ..... also, the maximum difference temperature is fixed, and is around, for good working conditions, like 70C ..... this mean that the temperature that you can reach on the "cold" face, depend mainly abut how much "cold" you can keep the "hot" face ..... like, if you can keep the "hot" face at 70C, theorically you can reach 0C on the "cold" face ..... but this only theorically ..... you must also keep in consideration the dispersion between the junctions, the dispersion of the parts in air, thermal resistance of the parts connected, mutual thermal resistance from cold part > air > hot part, and so on ..... in short, you may be lucky if you can have a difference of 50C.

So, keeping the "cold" face around 30C, you need to have the "hot" face (and the heat dispersion system) at 80C or less, and continuously draw away the heat ..... also, considerate now if your diode developes 1,2W of heat ..... if your TEC can transfer only 1W, the remaining 0,2W does not become transferred, overloading the system and quickly rising the diode holder temperature (remember that, with the TEC system, the "cold" part of the assembly is NOT exposed to air, nor heatsinked from the ambient, so also this small 0,2W can quickly rise the temperature, til the diode burns).

Those are just examples, but can give you an idea .....


EDIT: i just remembered, i read some times ago about a company called Micropelt GMBH, that was announcing new generation of thin-film TEC coolers ..... maybe these new technologies can be more efficents and valid, for this specific use ..... but, being new technologies, i don't dare to just imagine how much can cost one of them


EDIT2: just found again their site, and there's something new, respect the time i seen it for the first time ..... thermogenerators ..... does come something in mind ? ..... a TEC thermogenerator, specifically designed for generate current from heat, with a black adsorbing face ..... who said LPM ?

if my build gets too warm I run some water over the outer surface of the host. cools the outer layers of the host instantly, keeping the temperature gradients nice and steep
ofc, you need to be careful the water doesnt get in any openings.
Im tempted to turn mine up, but from what I understand the 18650 jayrob host comes with a boostdrive, so I cant put it above an amp. Not a huge host anyway, might want a big torch host for ~1.5A lol. Maybe the arctics can be pot modded when they arrive. If their heatsinking seems sufficient, at least we know the diodes should be ok unless WL give us the crappy ones.

Very good EF glad to hear this +1 for you bud !

ElektroFreak said:

I've got two on my lifetime test rig that have been running 24 hours a day for over 4 weeks straight, one @ ~800mW and the other at ~1W. They're both still going strong with no observable degradation.

Click to expand...

Good info EF. Also keep in mind the host will reach these temperatures and you will not be able to hold it. However there is one good thing. The hotter the hot side gets, the easier it is to dissipate heat. Its a lot easier to dissipate 3 watts of heat when the temperature difference is higher between the heatsink and ambient air temperature. That's good for lab style units that have a finned heatsink & fan. If you can get a fan and heatsink in a hand held, then that may work. Otherwise the host will just heat up faster and cause a shorter duty cycle. (most hosts are more of a heat dump then a heatsink)

CrazyMonkey said:

Good info EF. Also keep in mind the host will reach these temperatures and you will not be able to hold it. However there is one good thing. The hotter the hot side gets, the easier it is to dissipate heat. Its a lot easier to dissipate 3 watts of heat when the temperature difference is higher between the heatsink and ambient air temperature. That's good for lab style units that have a finned heatsink & fan. If you can get a fan and heatsink in a hand held, then that may work. Otherwise the host will just heat up faster and cause a shorter duty cycle. (most hosts are more of a heat dump then a heatsink)

Click to expand...

Not really. The temperature difference between the host/heatsink and the diode is what is important. Sure, if the host gets hotter, it will be dissipating heat into the air faster, but if it stays warm it doesnt matter. your diode is still buggered by being unable to transfer heat to an already warm heatsink lol.

Tech_Junkie said:

Me too. Mines still in the mail from Italy. 140, 1.4A. I'll throw it in a pointer to show my friends, then its going in a ray gun.

Quick question. Can I use a TEC to keep it at 60C? Should I use a driver, or will a pot work?

Click to expand...

Uh, do you mean that you still got no news about it ?

Let me check with the tracking number.


EDIT: very strange ..... postal system site say me "In lavorazione presso il centro postale di MILANO CSI WINDOWS in data 20-LUG-2010" (That means, they are "working on it" on Milan postal site from 20/07/2010) and no other informations ..... when i send the others, the tracking informations always showed "sent to USA in date ....." and never "working on it" .....

Trying to contact them via phone .....

Edit2: finally got to talk with them ..... the operator said me that the site is not updated, and that the package was sent to USA in date 20/07/2010, but said me also that, after this date, they have no ways for know where the package is, cause it's the receiving postal system that have to give the remaining informations.

T_J, i PMed you the tracking number (my bad to have forgot to do it immediately, apologise for this), if you want to check with USPS, but postal operator also said me that the shipping from Italy to USA takes, indicatively, around 14 days.

Fonduman said:

Not really. The temperature difference between the host/heatsink and the diode is what is important. Sure, if the host gets hotter, it will be dissipating heat into the air faster, but if it stays warm it doesnt matter. your diode is still buggered by being unable to transfer heat to an already warm heatsink lol.

Click to expand...

Yesm, I mentioned temperature delta.
My point was, it may get to hot to hold.
Maybe if you hold it with 2 hands, you can become
part of the heatsink.

HIMNL9 said:

T_J, i PMed you the tracking number (my bad to have forgot to do it immediately, apologise for this), if you want to check with USPS, but postal operator also said me that the shipping from Italy to USA takes, indicatively, around 14 days.

Click to expand...

Got it 15 minutes after your post. :angel:

Thanks again Bruno!!!!