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FrozenGate by Avery

DIY Homemade laser diode driver

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Just don't be in a rush for the items if you order from Deal Extreme. Give yourself about a 3-4 week lead time for the order. :o A slow boat from China takes time, ya know. ;)
 
i think i am going to go for the 6 cell method i already have a 4cell holder so ill just go to rat shack and get one that holds two tomorrow and add it on with some double sided foam tape since they dont carry a 6 cell for AA
 
man this is so frustrating . I just used a 9v source and i got 1.25v across the adj. and out but when i checked the current its still 208ma i don't understand what is wrong its not the 317 because i changed it out same results.
 
I checked and you are right...not that I doubted you...lol. It's just that I am really surprised they don't have any 6 cell holders.... :P Anyway, the regulator will behave much better with 6 cells.
 
Here is a good link to help you understand how the LM317 works and to double check your wiring.

http://users.pandora.be/davshomepage/current-source.htm

As long as you have everything wired up correctly, you should be seeing 250ma's. Check the resistance of the 5 ohm resistor with your ohm meter. I really don't know if a 10 ohm resistor is going to be low enough. As I recall Chimo suggested using an 8 ohm resistor as a load and it worked.
 
Well if it makes you feel any better you said AA or AAA and they had a AAA 6cell. lol
 
well can anyone tell me what i have wrong i cant figure out why my readins arent right with this set up I get 1.9v and 189ma
 

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update when i use the unfused side of the dmm i get 250ma why is this different. shouldnt the out voltage be higher than 2
 
Hi Can I construct a laser driver with components I can find In copmputere pieces? RESistors ANd capacitors I think yes but what about the voltage regulator?? there is another way to have the same effect??
I have a 16x Sony diode.

I pull off this circuit from a laser driver I had yuo think I can fit with my new diode?
 
is there a way to discharg your capacitor before attacing your diode. i used it on a 5 mw laser and when first connected it gets really bright for a second and then dims to normal. i think that this spike will kill my diode so please if anyone can help it would be great.

thanks alot,
mitch
 
You can discharge it by shorting it, of course with the power turned off.
 
yea tryed thet but still the same.

but this varience is only visable when the current is very low is this a sign of a problem in my circut or is this normal?

Thanks,
MItch
 
I notice a spike when I turn on my power supply on my labby. But since the laser is current adjustable, I always make sure the current is turned all the way down before I apply power. If you are using batteries, they might be sagging quickly...it's all I can think of off hand.. :P
 
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