Red Senkat diode not strong with 250ma?

I can't figure it out, but my senkat diode seems to be operating with 253ma, I checked it with a dummy load, then again with a 1ohm resistor in line with the red laser diode.

but it seems to have the brightness of a 5mw laser diode, is it dead? it sure won't burn the same stuff my 140mw red burner burns, weird...

voltage between vout and adjust is steady 1.234(it climbs .001 every few seconds)

voltage to diode = 2.81
mv across 1ohm resistor = .253

I actually had the balls to try this setup at 1.25ohms, no brighter for some reason, it's definitly a focusable dot, even at 300ft away it's focusable, so it's still laser, but it never was bright or burned anything.

Assuming you had the 1-ohm resistor hooked up in series with the laser diode, you may have optical damage on it. To rule everything else out first, what input voltage and source are you using into the driver circuit?

I just swapped the senkat for a 140mw red diode, change the resistors and it works, burns, etc... I'm going to have to assume the senkat has optical damage somehow? I guess it's time to take out the diode and look at it.

oh yeah, it's got two 3.44volt rcr123s, and while in operation, the voltage stays above 6.5v, it didn't ever drop too low, and I always used freshly charged, etc, shorted the leads before connecting diode, i was grounded, I just think I got a bad senkat diode by chance, bummer!!

It's quite possible, and it sounds like you've done your homework on debugging and testing lasers, too. You might want to consider the possibility of popping the diode out of the housing and removing the can. I've run into a few with damaged and/or broken windows, and they ran far, far better after the can was opened. This may not solve the problem with your laser, but it's worth a shot.

It is very likely that your diode is now just an expensive LED :'(
Take out the lens and shine it at a flat surface. Take a picture of you are able. We'll know more at that point.

I purchased 5 senkat diodes from sales.stonetek.org and none of them would burn! Of course I was only hooking them up directly to a minimaglite though.... they are very bright... but burning, not a chance. I am buying 10 of the BlueFusion GB drivers, will this solve my problem?

Well, for what it's worth, I purchased 3 Senkat diodes. The first one CRANKED! It lit matches and basically tortured anything that was a dark color- burned holes in CD cases, electrical tape (cut it), plastic trash bags... good hot beam.

The first one I cooked was because I was using a socket for the diode. While focusing one evening, I pushed the diode out and back into the socket - in about a milisecond - but it was enough to spike the diode and cook it.

So diode number 2 is in place. Running DDL's driver (LM317) with a 3 ohm resistor and I am cooking things like a chef! The beam is HOT, hot enough to actually feel it on my skin (after a second or two) - and hot enough to ignite a match with no perceptible delay. Senkat's (Sony) diodes are running upwards of 200mW for a lot of folks here. I am thrilled with mine, and will be using those diodes in my next project which will be a multi-diode array using cube splitter/combiners to create a beam around 1+ watt for some serious fun.

My observation - if you're careful with the circuit and take your time, you'll get excellent results with the Senkat (Sony) diodes.

Dave

spinout, you have to focus them to a spot to burn best, unscrew the focusing lense on aixis module to where its almost falling out them the focus will be about 2inch away, keep trying till you find the smallest spot, when you find it you can light matches in a flash burn dark wood, melt plastic etc.

...lazer... ;D ;D ;D

iv done that and still get no heat.... i had it on the smallest spot i possibly could, and still nothing. And btw... when I unskrew it to that point the beam get arger again...

Were you holding your hand in front of it to feel the heat, because that wont work, the only way you could feel it on your hand is if you put a dot of sharpie on your hand, then you can feel it and find out if its working, if it gets bigger when you do that just move the object forward and backward to find when it makes the smallest point.

...lazer... ;D ;D ;D

dead diode... *cries*

w00t i got it to work!!! I dont know why I couldnt before.... Will a driver make it burn better? BTW put black sharpie on my arm, now that was cool

Video coming soon!

Driver - YES! You can "tune" a driver to provide a drive current and voltage that is tailor-made to your diode. Uses an LM317, a 5 ohm resistor, a small pot, a 1N4001 diode and a 47uF+ Tantalum (or electrolytic if no Tant avail.). Total cost for parts about $5.00, and you will get a driver that will get the max power - and life - out of your diode.

Here's the link to the driver circuit/info:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1185701612

I use this driver and have had nothing but awesome results.

Dave

xanatos said:

So diode number 2 is in place. Running DDL's driver (LM317) with a 3 ohm resistor and I am cooking things like a chef!

Dave

Click to expand...

So you are running an excess of 400ma's into one of the SenKat diodes?

spinout059 said:

w00t i got it to work!!! I dont know why I couldnt before.... Will a driver make it burn better? BTW put black sharpie on my arm, now that was cool

Video coming soon!

Click to expand...

I am glad you got it working but what's up with your signature? Don't you know you are supposed to already have goggles

Gazoo said:

[
So you are running an excess of 400ma's into one of the SenKat diodes?

Click to expand...

No, measured with a 3 ohm resistor is 285mA. Not sure what the reason, but I measure with a meter and tuned by paralleling resistors. Probably will be different with a different diode. I have a 20 ohm pot in series with the 3 ohm and I currently have the pot set to min.

Dave