Question about the 1w 520nm diodes

[FutureOne]

Hello everyone.

I'm starting to get the itch to build something with a 1w 520nm diode.

From the spec sheet, it looks like it's designed to use a max of 1.7A of current (and this is where it will achieve the approx 1w of output).

So assuming that I build a unit that tops out at 1.7A, what's the max longetivity I can expect out of the diode?

Now let's say I bump it to 2.4A. How much longetivity would be reduced in this case?

Appreciate the info.

 

[grainde]

Hi cant give any info about the longevity, but if it helps I recently built one at 1.8 A with a Lazerer X-Drive V7. Even at this current the diode gets quite warm, so make sure the heat sinking is good! :beer:

Edit: Here you go, this is how I improved the heat sinking of the diode. 10, 20 and 50 Euro cent coins are Nordic Gold ie mainly Cu 89%, 5% Al, 5 % Zn and 1% Sn. This means they have a very high thermal conductivity and work very effectively as a heat sink! They are also almost a perfect size for most 18650 hosts. Basically sand the coin down to the right diameter, then drill it out (just wide enough for the diode pins to pass), sand it perfectly flat on one side and finally thermal epoxy it to the base of the diode. Here's a pic, which might explain it better

 

[FutureOne]

lol that's too awesome man!! I wonder how Canadian currency would stack up to do duty as a heatsink

Any chance I could purchase a few of those coins from you?

 

[grainde]

I guess I could sell them for a dollar each! :crackup:

Only kidding, just go to a bank or currency exchange and get some 10 cent (EURO) coins... :beer:

P.S € 10 cents is around $ 13 cents.

 

[FutureOne]

it's ok, 13 cents Euro is probably the equivalent of a Canadian dollar anyway lmao.

But yeah I will check out some currency conversion places.

 

[Down with Umbrella]

Your Canadian $2 coins would make a pretty cool diode heat sink addition. Is the center bronze and the outer portion nickel?

 

[Pman]

This is a great idea. Can't REP you yet but I always appreciate ingenuity.

 

[Thengine]

The diode is currently being driven at 2.4A in some builds. The key issue is waste heat, and proper heat sinking. I made some graphs a while back as I was considering a 2.4A build. DTR was very helpful in answering some questions about the diode and what direction would be best as far as the build is concerned.

This is the Projected output using a 4th order polynomial regression. I used Polynomial Regression Data Fit

This is the actual output as measured by DTR.

This shows the waste heat generated at each amperage.

As you can see, the diode is creating massive amounts of heat. The diode is generating over 11W of waste heat at 2.4A! This means you will have to run a short duty cycle or have a massive sink. I think 2.4A is the sweet spot as far as output and efficiency is concerned. DTR's "The Hulk"TM shows the benefit of having a massive host for this diode and a 2.4A buck driver.

 

[lazeristasUVISIR]

Osram did calculations on heatsinking of diodes.
http://www.osram-os.com/Graphics/XPic0/00094250_0.pdf

While it was for 450nm, it is valid for 520 too.

 

[FutureOne]

Oh wow! thanks to thengine and lazeristasUVISIR for that incredibly detailed information!!

11w is a lot of heat for such little surface area! yikes!. Still a worthy project though. I wonder if the prices on those diodes will fall. Even twice the cost of a 9mm 445 would still be a phenomenal deal!