Leadlight green laser current draw survey

[sbk]

Cybersoga could you tell me if you get a response from Leadlight please?

 

[cybersoga]

I asked

"Hi, I was wondering, what is the maxumum safe current you will adjust a 5mw green laser pointer before it leaves the factory?"

This was their answer:


" Did you want to adjust the current?? Actually, we don't recommend users to modify the laser.

If there's any problem, please feel free to contact me, thank you so much.

Best regards,
Novia Lu
Leadlight Technology, Inc."

 

[sbk]

/ubbthreads/images/graemlins/ooo.gif

For my laser, I just make a short circuit between the pot and the case (I have take the risk of all broken /ubbthreads/images/graemlins/grin.gif))

The result is..... the power has increase again!! It is very brighter than before! /ubbthreads/images/graemlins/cool.gif

Before it puts 40mW with 360mA, now I don't see, I have not my multimeter here. But I think it is about 50-60 mW !

I have made a website with pictures on
web page if you would see how to do and the result...

 

[4sevens]

I just got a 40mw from wickedlasers.
It draws 310ma.

 

[sbk]

Update : I have measured the power of my last modification of my Leadlight, with a green LED : it is about... 97 mW (with 750mAh energizer NiMh battery)!
Current is 520 mA.

Who say more? /ubbthreads/images/graemlins/wow.gif

 

[cmacclel]

SBK can you explain your mods for us?

Mac

 

[FNinjaP90]

How do you measure it with an LED?

 

[Uisgdlyast]

[ QUOTE ]
cmacclel said:
SBK can you explain your mods for us?

Mac

[/ QUOTE ]

Please do, i know you changed a resistor to get 360 but did shorting the pot really up it to 520mA?

 

[sbk]

I have placed all the information on the modifications and how to measure the power of the laser on my web site :

sbk site's (sorry for the irritating advertisement on my site, I will soon find another host).

And yes, shorting the pot with the + polarity (the case) did the current up to 520mA, with my NiMh battery. I have tested that this afternoon with a power supply, but I have limited the current to 540 mA, and it draw it.

I don't want to go upper than 520 mA, I think I have a lot of chance with this laser (my first green laser!) and I want that it lasts for a long time /ubbthreads/images/graemlins/happy14.gif

 

[lasercrazy]

I always thought that my modded laser was putting out about 30mw. But after it beat my buddy's 40mw I'm starting to wonder just what is it putting out? Oh it's pulling about 315 ma.

 

[Shiftlock]

Okay, I have another wickedlaser report. I haven't measured the power output myself, but I do believe the 42mW rating that was written on the box. The current draw is 309mA. If I short the pot to the housing, I see a noticible increase in the brightness, and the current draw jumps to 326mA.

 

[sbk]

Also nobody didn't obtain 500mA by shorting the pot with the housing?
It is possible that is because I have changed a resistor on the board?

If somebody wants to try that for confirm my increase of current...

 

[moshen]

sbk which resistor did you change ? By completely taking off the high resistor flanking the pot I can pull 360mAH. By shorting the pot (do you short the center of the pot or outside?) I can then pull 400mAH but never in the 500mAH range...

 

[sbk]

I first change the 1k (102 marked on it) resistor on the top of the pot (then the board is on the right of the diode), I replace it with a lower value (0.5k). This allow 360mA.

Then I replace the 2k resistor down the pot (202 marked on it) by an higher value (3.7k). This resistor define the higher current level that the pot can allow. With that it allow only 380mA, but I havn't tryed other value of resistor.

Then I have connected the center of the pot (the part which turns) to the case (the positive pole).
If you want to solder this properly you have to find with an ohmmeter the same electrical point than the center of the pot where you can solder a wire (it is a condensator like a brown square on the other side of the board).

Finally connect this point to a point that is connected to the positive pole (for exemple on the diode).

I will put pictures of that this evening...

Good luck /ubbthreads/images/graemlins/grinser2.gif

 

[moshen]

I get 360mAH. But again shorting the center only gets me about 400mAH.

 

[Uisgdlyast]

i'm going to try and remove the 202 one when i get a new solder tip. Would you recommend replacing this one or just leaving it blank? Also what values would you recommend for each? i dont want to be pulling too much current, but i dont want to be pulling too little.

I want to turn the diode though, anyone have tips for loosening the brass ring? I'd rather get more poswer without increasing the current.

 

[sbk]

Correction : the 202 resistor is remplaced by a 2.7k, and the 102 by a 390 Ohm. I recommand you replace it with another like me, but I'm not sure what it change. I don't have tryed with no resistor.

Moshen : also just test to change the other resistor /ubbthreads/images/graemlins/smile.gif

 

[Uisgdlyast]

i think i'm just going to change the 102 to a 100ohm resistor, then i'll just adjust the pot so it doesnt draw a lot more than 400ma

 

[sbk]

I'm not sure that changing the 102 resistor will change a lot, have you tryed to change the 202 with a bigger value?

 

[Uisgdlyast]

[ QUOTE ]
moshen said:
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

[/ QUOTE ]

So do we use 4.5 or 2.8, it is a big difference and on the greenlaser forum it says 2.8 and that is also what sbk is going by according to his site. I'm going to get an LED today(probably).