To fix the alignment issue I removed the expander lens/OC and glued it down so that the beam was more centered with the collimator lens. After I accomplished this the beam still exited the aperture at a large angle (est. 20-25 degrees from center). This makes me think that the crystals are not aligned properly, throwing off the whole optical assembly.
When I saw that the crystal holder was held "above" the surface of the module, simply sitting atop globs of glue (rather than something more accurate like a spacer), I had wondered how they managed to align it correctly. It seems like perhaps they don't!
Alignment of the lenses definitely has an effect on power.
That's good to know - Thanks! :yh:
I did not adjust the pot....
I only had it running for 5-10 seconds at a time...
I put the module in a brass heatsink for additional cooling.
OK, that eliminates several possible causes...
When my module died I was testing the alignment...
That got me to wondering. Given that the crystal holder is
metal, and the diode is
open-can, and it would be
VERY easy to brush the back side of the crystal holder against the diode innards...
could you have accidentally killed the diode from ESD while trying to re-position the crystal holder?
Normally with dead greenies I get the "dim red glow."
...or perhaps accidentally bumped and damaged the partially mirrored end of the diode, turning a dim-looking high-power IR laser into an invisible low-power IR LED?
Did it die while it was running? Or did it just no longer work after the last crystal alignment was made?
It's possible that the driver does not regulate voltage very well and the over-voltage killed the diode...
I get zero output from the diode. This means either the driver is malfunctioning or the diode is really cooked.
disma's post seems to indicate driver failure as a good possibility. He also indicated the driver itself got very hot at 3.3V, and you were running at 3.4?
I just checked, and that output transistor does
NOT have any heat sinking attached to it
at all :undecided: (not even a large copper pad on the PCB where the tab connects - just a tiny cold solder joint!)
These pump devices pull a
lot of current - I wonder if the driver itself just over-heated and died?
It's possible that the driver does not regulate voltage very well and the over-voltage killed the diode. If this is the case, these may not be able to be run on rechargeable lithium battery types at all without significant risk to the diode.
I have also read of some complete greenies that cannot be safely powered with rechargeables for that very reason.
If true, couldn't we use a suitable diode in series with a rechargeable battery to act as a "voltage drop", to bring it in line with what the driver wants? (Similar to how a diode can be used with a Flex Drive if the battery is a bit higher than 5.5V)
I can't test the driver at the moment as I have no dummy load (lost) and I also lost my good multimeter. Yeah... I know...
Has a LPM, but no DVM? We must live in alternative universes! LOL
I suspect the diode is either 1W and being driven at around 800mW or 500mW and being over-driven to well beyond it's rated limits.
Agreed. The first option would be safer, but not very cost-effective. Given this is a Chinese product, I fear the later option may actually be the case! :undecided:
BTW, I
finally received my True 5 from them, and am in the process of writing a detailed review. There is one thing I discovered, however, that is
very relevant to this conversation...
Peering down the aperture hole at high magnification, I could see the aperture piece was
"THREADED" inside where it meets the end of the module. I could also see down to the lens, which was at the top of the module, was larger, and the lens nut had those two shallow dimples...
From what I could see,
it appears that the module they are selling us may be the same design they are now using in their current pen lasers!
I reported visible manufacturing defects with
TWO of the screw-apart pieces that make-up my module.
You have also now indicated the
SAME THING -
TWO faulty pieces (defective lens alignment in middle piece
PLUS defective crystal alignment in base).
Almost like somebody selected two bad pieces, and screwed them together?
Given all of this, begs the question...
Is DX simply selling us the manufacturing rejects from its pen line as new modules?
)
, but only for 30 seconds. Hopefully he will stop by here shortly and give us the details!
?