all about lasers

[howry]

hey there,
im new in this great thing. here is my question and i hope to see some answers....
i took my diode from a cd writer , well it suppose to work right? give me some sort of lightning , but nothing. i found a circuit and i wired it as it was shown on the picture. but nothing happened!
help me with that.... im lost.....

 

[howry]

is that circuit looks right? tried to put 7.5v , 5v and even 9v, nothing happend.
maybe its a diode , but i dont know how to test if that thing works.
help!!!!!!!
what could be the other circuit for that? any one?

 

[pullbangdead]

Cd drives have infrared diodes.  Most people see a very dim red glow from them, but some people may not be able to see them at all.  BUT, they can certainly be dangerous to your eyesight even if you can't see the light.  My advice?  Get a visible diode (red from DVD burners/players or violet from BluRay or HD-DVD burners or players) to try first, that way you can see if there's light coming out or not, and see if it's actually lasing or if the diode is dead.

Also, what lines are connected on your board?  Without seeing what is connected to what, that picture doesn't help diagnose the circuit any.  Also, what value is the resistance you're using as the sense resistor?  I can't read the markings/colors to see what the resistors are or what they add up to.


ETA: Also, I assume this is the LM317 chip/driver? That's the most common one on this board, but without knowing, one can't properly diagnose problems for certain.

 

[howry]

dude, tnx for your comment and here is the circuit that im trying to copy.

 

[howry]

the back pic

 

[ElektroFreak]

It's really hard to tell anything from those pictures, but if you've never had any experience building electronic circuits, then you really should look at using ready-made drivers. I'm pretty sure there might be a few to be found if you look around this forum..

 

[hydrogenman15]

Don't ever turn that on cause your not gonna know if its working until its to late. However, you need an axiz module so you can focus the light into a beam and also heatsink it at the same time.
The light that comes out of the diode is coherent (waves move in sync with each other) but it will look a lot like a
flashlight without the axiz module.

You can get a nice strong red diode at http://stonetek.org/shop/index.php?main_page=index&cPath=67&zenid=107c966ba313f2bf344b10b95403bbaf

Its already press fitted so you don't have to mess up and kill it. Run it at 250ma's and it will love you forever.
Lots of people run theres at 350 but its not going to last as long.

--hydro15

 

[howry]

what about this kind of thing?

 

[Things]

That looks like a fiber optic transmitter. They arent lasers, just LED's ....

 

[hydrogenman15]

what about this kind of thing?

Nope, you kind of need an axiz module.

--hydro15

 

[Cyparagon]

That looks like the heat sink from the IR diode of many sleds.

 

[ElektroFreak]

I would definitely recommend doing some serious reading around this forum, and checking out http://www.repairfaq.org/sam/lasersam.htm (Sam's Laser FAQ). These kinds of resources will save you a lot of frustration when trying to build your own laser from scratch.

For a beginner, I recommend buying a diode already installed in an Aixiz module and a pre-assembled driver. Both of these can be easily obtained by looking through the sales and group buy sections of this forum. Doing this will also allow you to see how these things should be put together, that way when you do go to try to build one from scratch, you already have some idea of how it should go.

I don't mean this to discourage you, but taking the time to do some research first will help you out a ton in the long run, and the whole point if this forum is to provide a valuable resource for people (like you) who want to learn more about lasers as a hobby, and want to learn more about building homemade laser systems.

 

[jonrobertd]

To see if that IR diode and your driver are working use a camera phones camera, DON'T LOOK DIRECTLY AT IT PLEASE! Point the diode at a surface (use a dim lit area)  and look with the camera, it should illuminate the object. I use black construction paper and the IR shows up like shining a flashlight on it. Read up some and get a DVD-R diode. Don't feel bad I love DIY too. But it is easier to buy some things.

 

[mike666]

Just my 2 cents worth.....

But it looks like the laser diode (LD) has a lot of solder on it's pins.

LD's are very very heat sensitive. If the LD you are using is the red one, then there is a chance that you may have damaged the LD, by allowing too much heat from the soldering iron to fry it.

I could be wrong though of course lol.


Another thing I see is with the board itself.

On the curcuit diagram there is a capacitor, diode, 2 resistors then a pot.
You seem to have 3 resistors. The one nearest the regulator needs to be variable. If the value of the normal resistor you are using is too high, then your LD won't be getting enough current to power it.

Someone correct me if I am wrong. I am fairly new to all this too lol.

 

[jonrobertd]

Nope you are right mike666.
Also what values are the resistors, and this driver can be built without the pot.

 

[howry]

yea, it can be built without the pot!!! i found a circuit without that but still don't worked for me.
there is an update for my laser project.... hope that you will have any suggestions. don't think that my problem is with the circuit cause i tried that circuit with LED and it worked, but when i plug the diode burner its not doing anything. is it possible to check diode????????????