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445nm Brick!

jbtm

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Yes TTerbo, bought them all from woolworths at the same time :p

Although I don't really look 16 ... Maybe I was just planning a bonfire .. :p
Maybe you where going to do the mythbusters thing, by putting a lot of match heads into a barrel and lightning it off :D

Also thats one huge potentiometer...my Rheostat that was use for 1 amp operations didn't even get warm and it was half the size! Is it >270 degree turning or something?
 



Things

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I guess it pretty much is a rheostat, just a big wirewound potentiometer. And you are right, it doesn't even get warm :)

As for a price, I don't sell these, just made it for my personal use. I'm not really keen on selling these high powered lasers due to the liability that goes with them.
 

SpyderFire

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Things , can you put up a simple schematic/ parts for making your adjustable current set up?
 

Things

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Sure ..

This is pretty much all it is:



Since I am powering this from my nicely regulated bench PSU, and batteries, I didn't bother with the capacitor, diodes etc because I know my supply is clean. If you are going to be running it from a wall pack or something, you may want to add that stuff.

You calculate the potentiometer and R1 value for your specific diode. If you don't know the maths, this is helpful: LM317 Current Calculator - Electric Circuit

Enter the MAX current you want your diode to see. It will spit out a resistor value and rating. This will be R1. Make sure you get a resistor above the rating it states, or they will get very hot and may burn out. If they burn out and short, it'll send your full power supply current into the diode.

For me, my target current was 1.2A, which means a 1 ohm resistor, which is the white brick you can see in the image. The potentiometer (or rheostat) is a random one I had laying around. It adjusts from 0 to 5 ohms, and rated for 15W. This gives me a range of 1 to 6 ohms, which is roughly 1.2A thru to 210mA, perfect for these 445nm diodes. However for other diodes, you may need to find a higher resistance rheostat or you won't have a very good range. The potentiometer/rheostat should be rated the same way as R1, higher than the value the calculator gives you.
 
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SpyderFire

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This would be for a 445nm , and i think its perfect.

Its my next little project.

Thank you
 

wicked1

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I stocked up on some matches today while I was grabbing the rechargeable batteries too :D

Hah, if you were in the US, in the midwest, they'd have followed you home and busted in your door looking for a meth lab... (something about phosphorus in match heads being used in the process)
 

Things

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Yes it is ... the other end of the pot isn't connected to anything.
 

HIMNL9

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No, sorry ..... for have a current feedback, the current need to run through the resistor, and this mean that the resistor go from the output pin to the diode, and that is the adj pin that must go connected directly to the LD .....

Your configuration, i really don't know how it can work, cause the output pin is connected directly to the LD, so there's no way for have a current feedback, nor a stabilization loop.



Edit: i just thoughd about this ..... maybe, you have simply marked wrong the pins in the draw ? ..... exchanged the labels for VO and ADJ ? ..... in this case, yes, it can work .....
 

millirad

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^ How do you like the lm338k to run these 445nm diodes?

Pardon my slightly off-topic
 

HIMNL9

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^ How do you like the lm338k to run these 445nm diodes?

Pardon my slightly off-topic
LM338K is a "steroid doped" (LOL) version of the LM317 series regulators ..... you can use it with the same configuration of the LM317 driver, only, it's in TO3 package, and, with a good heatsink, it can take til 5A, and dissipate easily also 15 or 20W .....

Only, remember that it have a little more dropout of the standard LM317 one (around 3V at 3A load, if i recall correctly), and that, for work stable, it need at least 10mA of minimum load .....
 

CrazyMonkey

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I am pretty sure HIMNL9 is correct.
That's a voltage regulator configuration.
Except not connected to -?

Here is a standard current configuration:


BTW, my 445 is a brick as well..
Except it is in a crappy radioshack box..
Looks good!
 
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TTerbo

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I am pretty sure HIMNL9 is correct.
That's a voltage regulator configuration.
Except not connected to -?

Here is a standard current configuration:


BTW, my 445 is a brick as well..
Except it is in a crappy radioshack box..
Looks good!
the negative is connected straight to the Neg of the LD
the positive voltage passes through the Regulator.....i think
 

CrazyMonkey

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Doe.. I meant to say the pot is not connected to - in his drawing-
^^ ignore this
 
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TTerbo

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the pot doesnt have to be connected to neg i dont think?
his drawing looks good?
 




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