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ArcticMyst Security by Avery

Red DIY DVD laser burner.

C

Chris.

Guest
If it's intense then it isn't dead(yet).... diffusion will be normal as you have no collimating lens infront of the diode.
If you want to risk it, a >=16v 33uf capacitor and a 10ohm resistor would work in supplying a current of 280->320 mA at 2.8=>3.2v.
Use 2 AA batteries though :D
The capacitor would be in parallel across the diode pins, if you use a polarised electrolytic capacitor then make sure the polarities match. The resistor should be in series.

How did you measure the 122mA? that seems way too low for 3AA's
 





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ice

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theyre not AA batteries, but NiCd cells, being 1.2V each, not 1.5 as batts :). (dont have batts) and my measurment : +accu -> DMM -> LD-> -accu :-? anyway, i guess my DMM is dead [smiley=undecided.gif]. and what about that collimating lens? where to get them?
 
C

Chris.

Guest
You need an Aixiz lens..
http://mfgcn.com/
Just the 5mW one for like $5, we pull out the old diode and place in our new ones.
It really is essential for a good burning laser.

You need to take a step back dude.. take things slowly.
I blew my 18x diode doing just that lol, I got really excited and hooked 2 AA's straight upto it... died in about 10 seconds.
Seriously, just do this properly and you will have much more fun!
I'm in the UK so I used Maplins but I hear radioshack will sell LMT317's.
And that way, you can use any batteries > 6v.

Please take your time with this project! good luck.
We really are talking like $10 parts here after you have your diode, it's deffinitley worth it.
Check out daedals thread.
 
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ice

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so collimating lens from cheap pointer? :-?

im just fu... very :) courious if LD works or not, I am goin to make 317 current source next week. i hooked up like 12ohm resistor and 220uF :) cap, and output is next to nothing. without resistor i can see a red diffused thing on the wall... picture taken 1ft from wall, LD also 1ft, 2x1.2 NiCd (i think LD is dead)

I highly appreciate your time, tnx
 

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C

Chris.

Guest
Not dead for sure.
Just seriously underdriven...
You only have 2.4v!
I'd be quite happy to say that's fine until you build a driver.

With the bits you have lying aroud, it's either overdriven or underdriven =]
Maybe you could(if you'r bored) build a potential divider across the 3xNiCd batteries?
 
C

Chris.

Guest
Chris. said:
Not dead for sure.
Just seriously underdriven...
You have 2.4v at 200mA ;D
I'd be quite happy to say that's fine until you build a driver.

With the bits you have lying aroud, it's either overdriven or underdriven =]
Maybe you could(if you'r bored) build a potential divider across the 3xNiCd batteries?
Click to expand...

EDIT: You wouldn't see a dead LD at 1ft.
I say it's not dead as these high power diodes tend to just go, there isn't normally a period of gradual deterioration; It's either an LED or an LD :)
 
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ice

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"Maybe you could(if you'r bored) build a potential divider across the 3xNiCd batteries?" what you mean by "driver"? :). I have lots of parts lying around, except that damn lm317 :mad: :mad: :mad:

;D ;D ;D ;D sorry. I know what divider is, but cannot figure myself how to connect it (i mean resistance values) between LD and accupack
 
C

Chris.

Guest
I said divider :cool:
It's is where by you use 2 resistors to split a potential difference.
e.g.

If I had a 4v source, and placed say a 4 ohm resistor and a potentiometer across its terminals in series.
I would have a way or changing the voltage across the 4 ohm resistor.
so, if the potentiometer(or just a 1 ohm resistor) were set to 1 ohm, I would have
4v => 1:4
So, across the 4 ohm resistor I'd have 3.2volts?

I'll try find you a diagram... you should be able to see what i mean my placing any two resistors in series across the terminals of a battery, and reading the voltage in parallel across each of the resistors. It will change proportional to the value of the resistor.
 
C

Chris.

Guest
Like this.
Vout = Vin x (r1/r1+r2)
where r1 is the resistor over which you read potential difference.
 

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tvard667

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kenom srry really srry for bothering you about this so much :'( but its my first laser and im not that good with circuts yet i just cant tell from you video is the positive lead acutally touching the positive soider point? im a little confused bout that. and lastly i bought a new dorcy and i dont know how or where to mount my 10ohm resistor +-5% im embarassed to ask this but :-[ mabye some pics would help :-[srry agian i can understand if you dont want to help
 
Kenom

Kenom

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tvard667 said:
kenom srry really srry for bothering you about this so much  :'( but its my first laser and im not that good with circuts yet i just cant tell from you video is the positive lead acutally touching the positive soider point? im a little confused bout that. and lastly i bought a new dorcy and i dont know how or where to mount my 10ohm resistor +-5% im embarassed to ask this but  :-[ mabye some pics would help :-[srry agian i can understand if you dont want to help
Click to expand...

I'm confused what your talking about Positive lead touching the positive solder point? I actually hosted a video conference tonight to show three folks how I put mine together using skype.

I wish I could be more helpful to you in showing you exactly how I put these together. I no longer use 4 10 ohm resistors anymore since I've found a source for 2.5ohm resistors. I just use one of those.
 
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Things

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And that video confrence was VERY informative, and slightly funny at the same time :D
 
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tvard667

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okay srry about that kenom i was a little confused but after rereading you forum i figured it out ;Dbut i cant seem to find the right place to mount my resistor. :-/
 
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Zarniwoop

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Back to that resistor diagram for a sec...
It does show how to set up a voltage divider, but I hope nobody puts 12 Ohms across 12 Volts like that, unless they're trying to make a heater, or a temporary smoke generator. :)
 
Kenom

Kenom

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it really doesn't matter where you put the resistor on the negative pin or the positive pin. As soon as you add the resistor it reduces the entire circuit not from some point on. that was one of the hardest things for me to understand in electronics. Like water flowing through a pipe if you kink the hose at the top or the end it's going to slow the water down everywhere. Look for some pictures showing how I do everything soon.
 
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