low efficiency A140 diodes

[Bluefan]

I have a small problem, some/most A140 diodes I have seem to be a bit inefficient. I picked two average diodes and put them in a knife edge setup and I only get 2.5W at 1.6A, dropping of fast to something like 2.4W and below as it heats up. Running ti at 1.7 or 1.8A hardly gets more output of the diodes. I'm using the original lenses from the projector. The beams reflect of a single mirror, this is probably a ~13% loss, but that doesn't explain all te loss. I expected to more out of these diodes.

A while back I even killed a diode around 1.8A (LED'ed), supposedly an efficient diode. Anyone an idea what's happening or am I just overestimating these diodes? I see a lot of high power builds, nearly all with higher efficiency than mine My diodes are properly heatsinked so that shouldn't be the problem. I don't use the popular 405-G-1 lens, but in this thread the original lens actually performed well. Any one got an idea about this?

 

[sopark4000]

I think you might just be overestimating them a little bit. The A-140's aren't meant to be run at 1.8A.

 

[kiyoukan]

i think you want the new M series ones.

 

[InfinitusEquitas]

All the new 2W+ builds are using the M series diodes.

That's why now all of a sudden 2.1W+ is no longer such a rarity, and some folks have hit ridiculous high numbers with them.

Edit: A ton of testing has been done on A series diodes, I remember seeing a very nicely detailed thread with efficiency distribution. I was very surprised by the huge gap between the 2-3 highly efficient diodes in a projector vs the least efficient ones. IIRC the difference was over 30%.

 

[sopark4000]

All the new 2W+ builds are using the M series diodes.

That's why now all of a sudden 2.1W+ is no longer such a rarity, and some folks have hit ridiculous high numbers with them.

Edit: A ton of testing has been done on A series diodes, I remember seeing a very nicely detailed thread with efficiency distribution. I was very surprised by the huge gap between the 2-3 highly efficient diodes in a projector vs the least efficient ones. IIRC the difference was over 30%.

QFT. If you want to safely run diodes at 1.7A you need the M-140 diodes. Even for the most efficient A-140's 1.7A is pushing it. I think that when you say "I see a lot of high power builds, nearly all with higher efficiency than mine" that you're actually looking at reports for M-140 diodes. For example this is an efficiency plot for my M-140.

 

[Flaminpyro]

It sounds like you are over estimating the "A" series diodes and maybe confusing them with the "M" series that are making the 2000mW+ builds.

You stated you even blew out a High Efficient diode @ 1800ma :thinking: how are you coming up with that it was a high efficient diode ?? was it a "A" or "M" series ??

 

[rhd]

Honestly, this sounds par for the course.

At 1.6A, I'd expect around 1.4W from an average A140, if going through a glass 3-element lens. So double that, and subtract 13% -

(1.4 X 2) * .87 = 2.4W

Yep, right on target (and I didn't plan the numbers that way )

 

[DTR]

Honestly, this sounds par for the course.

At 1.6A, I'd expect around 1.4W from an average A140, if going through a glass 3-element lens. So double that, and subtract 13% -

(1.4 X 2) * .87 = 2.4W

Yep, right on target (and I didn't plan the numbers that way )

Was thinking the same thing. I have seen A140's that will give 1W @ 1.5A and ones that will give 1.6W with the same using a three element lens. That is a huge swing but smack dab in the middle the average is about 1.3W so 2.6W minus any loss from using the stock projector lens and any other optics puts his unit pretty close to par.

 

[Bluefan]

At least nothing weird is going on. I looked at a compilation of data in some other topic and most people for 1W around 1.1A, so I figured I could do better at a higher current. I expected differences, but not 1 to 1.6W at 1.5A. Anyway, I'm letting my diodes run safey around ~1.45A getting a 2.2W out.

The high power builds I mentioned were before the M140 btw.

edit: spread rep before bla bla bla