Leadlight green laser current draw survey

I thought it might be interesting to conduct a survey on what amount of current does your leadlight draw? My 17.8mw atlasnova draws 271ma with fresh duracell ultra M3 batteries.

Im gonna get one soon, and im curious, how do i tell?

Remove the battery end cap. Use a multimeter that can read 400ma and put the negative probe against a exposed metal part of the body of the laser (mine is chrome finish so it doesn't matter where) and the positive probe against the end of the battery, and press the on button on the laser at the same time. photograph in this post

here's a few i've collected to start this off...

moshen wickedlasers 42mW - 300mA
moshen self modified 35-40mW - 400mA
The_LED_Museum wickedlasers 25-40mW - 323mA
The_LED_Museum megalaser 15mW+ - 312mA
Crosman451 atlasnova 23.3mW - 205.35mA
Naquadah megagreen 5mW 210 mA
Naquadah megagreen modified ~25mW 240mA
stevieray 16.2mW 230mA

Atlasnova Leadlight 5mw running off of 2x Energizer AAA NiMH 850 mAh cells that have some use on them.
219.4ma

Since NiMH's are only 1.2v the current draw is a little higher then you would get with 1.5v alkaline cells.

If my math is right that should give me 3.8~ hours of run time before needing to recharge them. /ubbthreads/images/graemlins/smile.gif

I bought a <5mW stock Greenie from Z-bolt June 03' and wondering what kinda Max amphe'age can I apply to this thing before I need to start cooling it. I've been modding it the past few days on the Laser Driver Board only. I don't really have the means to play with the lens at the monment. So far I've removed the POT and replaced a few on-board resisters with weaker ones. My pointer now has a Total Resistance of about 4.6K Ohms (was like 14.4K Ohms)so by formula I should be pulling about 650mA (with fresh batteries that read 2.9V)but I'm only reading 550mA. Think It'd be wise not to push it much more w/o cooling. FYI I don't know what kind of mW I'm making casue I can't get the LED testing to work, I just keep getting way high MilliAmp reading off the LED when it should be Mirco. I think its just the type of LEDs i'm using so I'm planing on buying a little solar cell later this week at radioshack. Hope I get some feedback. Oh and "HI" I'm new to your boards and have found some very helpful info so far.


Here is a link to a pic of my pointer
http://www.users.bigpond.com/telescopes/green_laser_pointer.jpg

Derek~

Try a 5mm LED from radio shack. They come in packs of 2. I can get you the ratio that I've validated once you do that.

I'm using a 5mm Green LED (2.1 Volt/30mA/630mcd)from Radio Shack Part# 276-304, LED made of clear plastic and burns a yellow'ish green color when 2.7 volts is applied. So anyway Thats the LEDs i'm using =)

Thats no the same one I validated with my tests. Here it is here: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=276-022

With that LED my formula is mw output = microamps/4.5

Oh ok, I was thinking maybe I needed a green plastic one,

Thanks

Well Thanks moshen, That LED worked great,so I'm now at 700mA /ubbthreads/images/graemlins/frown.gif @ 45mW /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif Thanks for the help.

Diode gets extremely hot fast now(about 30seconds), so I'm transfering the MCA to a heat-sink with better cooling now

Most high powered DPSS laser pointers (green ones that I know of, and maybe blue ones too) have a duty cycle recommendation.
30 to 60 seconds on, 60 to 120 seconds off to allow the "guts" to cool.
That's a good place to start, anyway. /ubbthreads/images/graemlins/smile.gif

Unless you have a TE cooler (thermoelectric cooler that uses a peltier device) correctly incorporated into the laser.

DT_20 that sounds about right. Glad the LED method works for you. Others can reference that particular LED from radio shack and post their own measurements using my formula for themselves /ubbthreads/images/graemlins/grin.gif

[ QUOTE ]
Well Thanks moshen, That LED worked great,so I'm now at 700mA @ 45mW Thanks for the help.

Diode gets extremely hot fast now(about 30seconds), so I'm transfering the MCA to a heat-sink with better cooling now

[/ QUOTE ]

Don't expect it to have a long total lifetime. What this means is even if you TE the MCA and diode you're risking facet damage on your diode every time you fire it up even for one second. Additionally, the small MCA's are bonded with a glue that will darken quickly at those power levels. Once this process begins, it will heat up even faster and become more inefficient. It's best to keep these below 500 mA unless you're not expecting them to last very long.

Oh and BTW, for my contribution I had a leadlight that would do 6.64 mW (verified on calibrated Coherent Lab Master) with just 167 mA in at 3.000 volts. I got it up to 35mW at 335 mA and mounted it in a nice aluminum case made from an Energizer double barrel AA flashlight. I had the double barrel EDM'd down the middle so I had two tubes for other projects. Anyways, the laser was ruined when I dropped it overboard and it fell into the drink. I was attempting to illuminate a Secchi disk while taking a turbidity reading near the CBBT in VA.

Sorry for the long story! ~~~~~

Cheers!

Can I expect a quasi normal lifetime for my Leadlight 5mW pushed to ~40mW with 360mA? The diode warm a little after several seconds of use, but not too warm. I also project to made a nice box with a cooler for the module.
What do you think about the max current the diode can support?

That's not an excessive amount of current.

Remember, if the casing feels warm the diode is running too hot! These things will die quickly if operated with a case temp >40°C for long.

Fifteen to Thirty seconds on with a minute or two rest should provide a good balance between enjoying your device and reliability / lifetime.

Cheers!

So it is ok for the current. The casing isn't feel very warm, about 30°C max. I only feel the warm if I touch the unmounted module directly. So I can still increase the current for more power /ubbthreads/images/graemlins/smile.gif
But for that I'm thinking I have to modify again the circuit board, now the max pot position is doing 360mA.

Yes you can modify the board and get much more current. It's quite addictive but remember once you go too far, there is no reversal especially if the diode suffers facet damage!

You can get ok life at 550 mA but you *must* stick to a strict duty cycle or it will die quickly. Also the eye has a hard time distinguishing between 35mW and 60mW for example.

At 360, you're in good shape. Yours sounds a lot like mine and I would still probably be using it but these modules don't take to saltwater well at all. /ubbthreads/images/graemlins/faint.gif

Cheers!

Ok so I will try to mod it a little again... But I am rather afraid for the crystals than the diode, because I don't know which power they can handle without exploding.

I think the major difference between 35 and 60mW is in the
beam visibility, not much in a brighter dot. I already noticed that between 20 and 40mW.

Oh, and my condolences for your laser... I shall avoid approaching the salt water with mine /ubbthreads/images/graemlins/grinser2.gif

I was wondering, what is the spec for the diode in the leadlight pointer, and what is the max current leadlight will adjust a pointer to before it leaves the factory? *edit* just emailed leadlight...