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Warzon3

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Hello

Let's just tell you my intrests.
I play games (mostly Eve Online since internet spaceships are serious buisnes) I like almost anything that got something to do with electricity so far I've build a coilgun and am still looking into building a tesla coil (need to find time for it :p)

I'm new to lasers and soon I will be making my first one (parts will arive in 7-14 day's ohhhhh the waiting is so bad). My first laser will be using a PHR-803T diode and my aim is to run it around 100-125 mw.

Now I also got a few questions to put here as well.

mainly the driver part. I had found this picture: http://images2.wikia.nocookie.net/__cb20080816184914/lasers/images/1/1a/Lm317diagram.jpg but as I understand my diode needed a bit more volts to work and some other stuff so I looked around a bit more and stumbled on this and I must say great info there.

Now I edited the picture from rog8811 for my own build and from what I understand it should be this is there someone who can tell me if this driver could work for my PHR-803T?

The host I will be using got place for 3 AAA battery's but standard AAA will not work as they are 1.5v each and 4.5v will not be enough to run this thing. I've read about those lithium-ion battery's but most I see are AA size or are there some AAA size around somewhere? (I can probably modify the holder to take power from 2 instead of 3 AAA if needed)

And one last question: if there are AAA's I can use that put out let's say 4V am I right in the assumption I can just use 3 of them at a total of 12V and my driver will make sure that the diode doesn't fry?

Sorry if my english is a bit bad it is not my native language ^^
 

lasersbee

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Jerry
 

Morgan

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Welcome to LPF! :wave:


Take a look at the guides in my sig, (there is a handy current calculator in there that should help with your resistors when using the LM317). The driver will provide just as many volts as your diode needs so you only have to deal with current in this setup. The LM317 is working as a current regulator here not a voltage regulator.

For a PHR I wouldn't go much above 100mA to start. Yes, it is possible to drive them harder but as you will probably be aware, this will shorten it's life. Some drive them at 120mA but when it's the only laser you have I would recommend you stop at 110mA. This should give you somewhere around 100mW output, possibly a shade more, and this is plenty to start with.

Have a good read and enjoy your time here. Good to have you aboard.

We love pictures here too so post some when you finish your build but please limit them to 800 x 600 pixels so they present properly for all. Thanks.

M
:)
 

Warzon3

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Thanks for the replies.

edit: responsed to morgans post but more have welcomed me in the meanwhile it seems :p

I have been reading a lot about lasers for the last week and have come across all the links in your sig ^^

I get that the driver provides a constant current but current alone wouldn't be enough to run it right? So the voltage needs to be high enough for the diode to work (according to my searching around 5V) and the driver itself will use around 3V so if I use a 3 AAA battery's providing 1.5V each it will only give me 4.5V so that would be 3.5V short of what is needed as a minimum right?

Or am I totally wrong here and is it possible to run on current with a lower voltage?

with that current calculator I come at 12 ohm for 104 milliamps should be able to make that have hunderds of resistors here
 
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JIMS19

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I like to see questions and discussion about the technical aspects of lasers, good job! and welcome.
 




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