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Batteries with LM317?

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michaeloohra

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I'm building my first driver. I'm debating on using:
1 6v (lantern battery)
2 6v (lantern batteries)
12v adapter for an old land line phone.


I would prefer the battery(s), but I don't know if that changes the Formula:
1.25 / .125mAh = 10ohm resistor

Does the formula change if you use different power sources? I bought a cheap 100mW green laser. That is my diode. Note: 'Cheap' so I think .125mAh is plenty high for this diode. I'm only mentioning this to see if it helps.
Thanks!
 





chipdouglas

chipdouglas

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first off, if you bought a cheap 100mwgreen laser it won't be a diode laser. it will be a dpss. and 125ma will not be nowhere near enough current for this. post a link to it. it greens usually come with a driver. so you shouldnt need an lm317.

michael.
 
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michaeloohra

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So far I have:
Everything that comes with that laser
LM317 (radio shack)
10Ohm resistors

And the knowledge of new guy.
 
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michaeloohra

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Prototype said:
You're messing with just the IR diode or the whole module?
Click to expand...

The thing (lens?) covering the diode can off when I was pulling the driver and diode out. I can put it back on. But I didn't know if it mattered.

BTW

Module = Diode + thing (lens?) on top of it?
 
rhd

rhd

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You've got to post photos michael - otherwise it's really hard for us to get all the terminology in sync with what you're seeing :)
 
Prototype

Prototype

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michaeloohra said:
I only got the laser for a green diode. You are correct, it can with a driver. It was a laser pointer 'pen'. But getting a cheap laser, seemed easier for my first driver. PLUS if I messed something up it wouldn't be so costly.

Here is the laser though:
5 in 1 100mW 532nm Mid-open Kaleidoscopic Green Laser Pointer Pen - Tmart.com
Click to expand...
Well that wasn't really a green diode. Green diodes aren't even really beyond the testing phase for pico projectors, not that they don't exist, they just aren't widely available yet. Any green you get that you didn't pay thousands for is going to be DPSS or an argon line, but I digress. What you've got is a DPSS laser module that produces green laser light after a conversion process. I'll explain more below.

michaeloohra said:
The thing (lens?) covering the diode can off when I was pulling the driver and diode out. I can put it back on. But I didn't know if it mattered.

BTW

Module = Diode + thing (lens?) on top of it?
Click to expand...

The thing you pulled off, was it a small gold disk, with a notch in it and a small glass looking block that looked a bit purple under the light? If so, you removed the crystal stack that makes up pretty much all low powered green lasers, but quality differs from brand to brand, again I digress. That was what made your green laser green. The 5.6mm diode in that module is IR, 808nm to be precise. The crystals in that gold disk were an Nd:YVO4 and KTP bonded crystal set. The Nd:YVO4 is excited by the 808nm pump diode and fluoresces at 1064nm. This is then frequency doubled by the KTP to produce the 532nm laser light. It requires somewhat precise alignment with the pump diode. For your own safety, do NOT power up that diode without 808nm protection goggles. You can get it repaired by someone with 808nm protection goggles and some optical adhesive, but it'd probably be easier to get a new module.
 
rhd

rhd

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Ok - what you have is an entire green module which is basically: Lens, Crystal, Infrared (IR) Diode, AND Driver.
Check this out:
Diode-pumped solid-state laser - Wikipedia, the free encyclopedia

But the circuit there IS a driver itself. You don't need to create one.

That said, you CAN if you want to, but you'll have to remove the circuit board already on there. There's really no reason to do so. I've done it once, but only because I needed to run the IR diode off of a voltage the stock driver couldn't handle.
 
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michaeloohra

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Prototype said:
Well that wasn't really a green diode. Green diodes aren't even really beyond the testing phase for pico projectors, not that they don't exist, they just aren't widely available yet. Any green you get that you didn't pay thousands for is going to be DPSS or an argon line, but I digress. What you've got is a DPSS laser module that produces green laser light after a conversion process. I'll explain more below.



The thing you pulled off, was it a small gold disk, with a notch in it and a small glass looking block that looked a bit purple under the light? If so, you removed the crystal stack that makes up pretty much all low powered green lasers, but quality differs from brand to brand, again I digress. That was what made your green laser green. The 5.6mm diode in that module is IR, 808nm to be precise. The crystals in that gold disk were an Nd:YVO4 and KTP bonded crystal set. The Nd:YVO4 is excited by the 808nm pump diode and fluoresces at 1064nm. This is then frequency doubled by the KTP to produce the 532nm laser light. It requires somewhat precise alignment with the pump diode. For your own safety, do NOT power up that diode without 808nm protection goggles. You can get it repaired by someone with 808nm protection goggles and some optical adhesive, but it'd probably be easier to get a new module.
Click to expand...

Thanks! I have been curious. This answered a few questions I had. The way you make it sound is that 'I' won't be aligning the crystal (right?) up.
Not that I have taken offense; But because of lack of tools, and skill, right?

Anyway thanks. From what I've read online the IR lasers are extremely dangerous. Or atleast more so than the colored lasers. Thanks, I'll just get a laser and try again.

In the mean time. And mostly because I wanna see if I can make a driver that works. Could I use an LED? I have a rather big one from Radio Shack:
FW Current -- 20mA
FW supply -- 3.2V - 3.8V
 
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michaeloohra

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rhd said:
Ok - what you have is an entire green module which is basically: Lens, Crystal, Infrared (IR) Diode, AND Driver.
Check this out:
Diode-pumped solid-state laser - Wikipedia, the free encyclopedia

But the circuit there IS a driver itself. You don't need to create one.

That said, you CAN if you want to, but you'll have to remove the circuit board already on there. There's really no reason to do so. I've done it once, but only because I needed to run the IR diode off of a voltage the stock driver couldn't handle.
Click to expand...

I'm only doing this so I know how. BTW, Thank you all for the Info on lasers. But If i hadn't broken the piece off. What power supply would I have used? Or do I use a power supply EXACTLY as needed by the diode?

In other words, Can I use a 12V power supply, on a diode that normally ran off 2xAA batteries? Or, do I need to match them up?
 
chipdouglas

chipdouglas

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michaeloohra said:
I'm only doing this so I know how. BTW, Thank you all for the Info on lasers. But If i hadn't broken the piece off. What power supply would I have used? Or do I use a power supply EXACTLY as needed by the diode?

In other words, Can I use a 12V power supply, on a diode that normally ran off 2xAA batteries? Or, do I need to match them up?
Click to expand...


power supply for what? the lm317 or power supply for the original driver that came with the green laser module you have?

for lm317 you can use 12v. for the original you want to use i think between 3-5vdc

yes, you can use an lm317 driver to power an LED.
 
AUTO XX

AUTO XX

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You will have to heatsink the lm317 VERY well to let it drop ~10V off your power supply (IR diodes like ~2V) the extra voltage will be "burned off" as heat.
 
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michaeloohra

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Ok I use the AA and try the LED if I have more questions I'll post back. Thank you all so much!
 
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