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1A LM317 driver with current selection switch

alessnilsen said:
1975? Wow! Those things are old! For my searches, it support up to 35A.
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Do what ! 1975 isn't old ! I might be an antique. But I'm in the prime of my life. Now there is a sad thought :crackup:

I thought it looked familiar. I'm going to keep my eye open for one. I'm around a bunch of industrial equipment that converts alternating current to direct current.

"Here`s your problem, your rectifier is missing." Lmao !
 





Yeah! I have a big capacitor dated 1987, is a bit old, a Siemens 16000uF 50V from a Elebra Emilia PC.
It's a cute big heavy capacitor that I use to make some sparks when I'm bored. It's a good filter cap for those antique diodes! :)

Here is a preview of my laser without the laser:

2014-08-06%2013.30.50.jpg


I done some modifications on the driver, I added a big output cap, from 4,7uF to 220uF, it will reduce the switch contact bounce effect a lot!
I added too two 104 ceramic caps, one at input and other at output, to filter the high frequency noise from the SMPS.

I was thinking, what is a good value of capacitor to put in parallel with the LD? I think a 104 will be fine, but I'm not sure.

Just waiting for the module/heatsink and the laser diode arrive! :)

The heatsink is a piece of 3,3cm X 3,3cm X 5cm, I don't know if is enough for 1W.

Laser-Module-Housing-33x33x50mm-for-5-6mm-TO-18-LD-with-Glass-Lens-Fans.jpg


If not, I'll adjust the current of the LD to match the heat dissipation.
 
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If you parallel LM317 regulators , its best to add 0.2 Ohm resistors in series after the current set resistor and before the load , it helps keep things happy apparently .

I did the same to get 20A CC from 20 LM317 regulators in parallel :P
 
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Glad your project is coming together :beer:
It's a lot more fun building everything yourself. I hope my DigiKey order shows up today and I don't have to work this weekend.

I've been spending a bunch of time at TI`s site, they have some really cool design tools for regulators then you can export the design to Eagle.
 
Here is a pic of the LM338 I was telling you about ! Told you it is worth a laugh :)
Looks like Mickey Mouse !


 
That's not too bad! :beer:

I still waiting for the laser diode + heatsink to arrive, all the other stuff is already assembled.

I never seen a 445nm laser.
 
Thanks. I thought it was pretty bad. It was just a test. But it works.
Hope your parts show up soon, that's part of the fun, collecting pieces.
I like the 445`s. The entire 400 range is my favorite. The closer it gets to Teal the more I like it. :beer:
 
445nm seems a great color, I only have seen 405nm and is a wonderful color! :yh:

I finished mounting all the stuff into the wood board, here is the result:

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What do you think? It will be like my computer sound amplifier mounted into a MDF board, the manutention is very easy.

:whistle:
 
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I think you made it look like a nice clean installation. Good for you for taking pride in your work :beer:
 
Today I received the LD:

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Now I'm thinking, should I test it now? The heatsink don't arrived yet.

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I tested it, 445nm is a beautiful color!

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Please be aware that your wrist strap is 100% useless unless you ground it with a cord.
 
Thanks for the advice! I touched a ground wire before touching the LD.

Those wireless wrist strap are useless, I'll attach a cord on it! :beer:
 
Also, not a good idea to post your full name and
address in a public forum, especially when you are
holding very expensive devices.
 
My mistake, already corrected!

Thanks! :beer: :beer:

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Another question, Is all OK with the RAW output of my LD? I know that's is multi mode, but it looks a bit "hairy" with spurious emissions around the main beam (you can see the entire diode aperture with little vertical beams).

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Tested again! NICE color! :drool: :drool:

At 285mA:
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At 1A:
P1460380.JPG
 
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Is best to drive this LD with 1A or 800mA? I think that the difference of output power will be compensated by the longer lifespan.

I'll drop the low output from 285mA to 175mA, I see that at 285mA it produces a lot of light, when in this mode I only wan't a pointer. The lasing threshold is at 150mA, when cold, it lases, but after a few seconds the lasing process stops and it start to produces LED light, is interesting to view this. Because of this I will drive it at 175mA, that's enough for it.
 
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