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Direct-Drive 445 Host

LarryDFW

LarryDFW

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This is my latest 445 build for long run times (15 min. or so).

I started with this mount for the Aixiz module:
6xheatsink.jpg

It is a very tight press fit with thermal compound.
The back side of the Aixiz module has a generous amount of heat-conductive epoxy in contact with the aluminum heatsink.

The front aluminum disc is pressed tightly against the finned heatsink shown in this photo:
finhx.jpg


The battery is a brand new nickel-anode hi-voltage 2800mah 18650 for long operating cycles.
Operating current is 600ma with Direct-Drive to the diode.
Efficiency is the highest possible, since there is no driver consuming power.

Lens is my Hi-Power 445 with stainless aperture to reduce wings.
This lens provides maximum power output for a set current (~520mw)
Here is a beam shot slightly defocused for best pattern:
445nm.jpg


Of all the lasers I have built, I like the dynamics of this host the best:
uv8.jpg

"Strong Light !" indeed.

LarryDFW
 
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Very nice indeed Larry! :beer:

I like that host as well. It looks like with the finned heatsink and ventilation holes it will provide maximum cooling.

Do you have a link for that host? Every time I look it up at DX it states "temporary out of order" which says to me they won't be getting it anymore. :(
 
I buy them in quantity thru a broker, for my 6-watt UV LED lights that I sell commercially.

My next build in this host will be the hi-power Casio Red LED I got from Daguin.

I have been playing with current levels,
and flooding my work area with the very intense Red beam.

Not a laser, but still hard to look at !

LarryDFW

P.S. I can provide the finned-host, if you don't find it.
 
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LarryDFW said:
My next build in this host will be the hi-power Casio Red LED I got from Daguin.
I have been playing with current levels,
and flooding my work area with the very intense Red beam.
Not a laser, but still hard to look at !

LarryDFW
Click to expand...

I would be VERY interested in your work with this. These red LED's just keep piling up :whistle:

Peace,
dave
 
daguin, what are you thinking about?

the close relative to this LED, the white SST-50, is already being used in a few portable hand-held flashlight builds. Might be easy to put it in a maglite.
 
BShanahan14rulz said:
daguin, what are you thinking about?

the close relative to this LED, the white SST-50, is already being used in a few portable hand-held flashlight builds. Might be easy to put it in a maglite.
Click to expand...

Just thinking about playing with one of these LED's

I am a clueless NooB when it comes to most electronics and LED's in particular. Can you give me a link? :beer:

I'm sure that I can search it up from the "SST-50" model you gave, but if I can be a bit lazy, I could use it right now :undecided:

Too many projects on the workbench :yabbem: (and too many students that are not ready for college in my summer session classes)

Peace,
dave
 
daguin said:
Just thinking about playing with one of these LED's

I am a clueless NooB when it comes to most electronics and LED's in particular. Can you give me a link? :beer:

I'm sure that I can search it up from the "SST-50" model you gave, but if I can be a bit lazy, I could use it right now :undecided:

Too many projects on the workbench :yabbem: (and too many students that are not ready for college in my summer session classes)

Peace,
dave
Click to expand...

LEDs are just like a laser diode, except different casing (sold on "stars" - metal bases), not coherent, less sensitive to ESD, driven at higher currents, and more tolerance to temperature and over-currenting. They also run hotter on average.

Luminus are the company who produce these projector LEDs, other producers are Cree and SSC (Seoul Semiconductor). DealExtreme stock plenty of cheap but high-powered LEDs.


EDIT: Checking the LED model now...

I believe this is the model of Red LED: http://www.luminus.com/content1090 but I'm not certain.
 
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If you search at cpf for sst-50 and sst-90, you'll find some info on people building with these high-output LEDs, but they are the white, domed versions. You will also find some people offering batches of 5A and 9A drivers.

This thread might be interesting, but you should do some searching, there's a pretty good google search there too.
 
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im assuming theres a reason that it can be direct driven when usually its not advised?
 
@BShanahan Are you sure that's the right LED? The one I have seems to be 2mm by about 2.7mm die size, making it a PT-54. I might just be measuring inaccurately. It's almost certainly nearer 3mm than 2mm on the longer side though. I also think I remember 8A continuous as being safe, but again I'm not sure where I heard that.

EDIT: I took a picture next to a ruler, and got 2.6mm by 2.05mm, by using photoshop's ruler tool to compare the die to my physical ruler. 2.7 by 2 seems to be the closest on Luminus' site.

@Fonduman "Direct drive" - you mean running it at its pulsed rating continually? It's because we don't generally require the full lifetime of 60k hours, so overdriving them might make them warmer and last less long, but it doesn't matter as much. I'd still run at a safe temperature and rated current, but maybe that's just me.
 
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Dave;

The Red LED is on a nice copper heatsink.

But it is too big for nearly all hosts.

So the trick is to cut it down to size.

LarryDFW

P.S. I think Charlie is correct about the PT-54
 
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I just checked it by photographing it and comparing with a physical ruler, that gave 2.64 by 2.05, which is closest to the PT-54's 2.7 by 2.
 
i thought without a driver you could get current spikes and stuff. and i guess theres the problem of the battery not being enough voltage and stuff, perhaps you just have the right power source for it.
 
Nice build Larry :) very interesting host with them cooling holes around the head it looks like it could be air cooled with a micro fan ;)
 
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