I need info on homemade burning lasers... can anyo

[Cronie88]

I am about to build a burning laser or two, from a 16x dvd diode and a 250mw 630nm red laser diode. I am a knewb at building lasers and I was hoping I could get some detailed info on this issue.

I need to know what voltage to use, the circuit board setup, and whether I should use a pre-made driver or make my own. I also need to know exactly what I will need to build both lasers.

Please, can anyone help me?

 

[CRFultz]

Re: I need info on homemade burning lasers... can

You can start by reading the many tutorial's that are available here. Your questions have been answered many times over.
Look at the stickies at the top. Most of the members here will be more inclined to help those who helps themselves.
Take a quick look and if you still have questions or you need a better clarification on something then by-o-means ask away

 

[Cronie88]

Re: I need info on homemade burning lasers... can

Ok. Well thanks, hopefully I can make the lasers right the first time. I'd rather not mess them up on the first try.

 

[dj_q]

Re: I need info on homemade burning lasers... can

i'll tell you a little secret. ...your going to mess up... its inevitable!

LEARN FROM YOUR MISTAKES.

one thing i have learned from my mistakes... always have extras!

 

[rog8811]

Re: I need info on homemade burning lasers... can

always have extras!

So very true, I almost invariably buy my LD's 2 at a time, as your experience grows you will find you have stock items you can dip into.

Regards rog8811

 

[Cronie88]

Re: I need info on homemade burning lasers... can

I was hoping someone could help me again. I made my own driver and I tested my driver to see if it will work with my diodes that I got. The only problem is that I might have miscalculated something on the driver, because when I test the driver with a DMM I get a reading of .84-.85V at the diode connection point. I am using a 9v battery for the driver and I don't know if it is too much or too little. I am not sure if .8v is 800mV or not, but my guess is that it is. so I am guessing that I need a smaller battery pack to get the 250mV or 250mA that I need for the diode that I am using.

Please help if possible!!

 

[billg519]

Re: I need info on homemade burning lasers... can

Well, we would need a little more info ... Is this an LM317 based regulator? You need a test load on the regulator in order to get meaningful measurements. You could try 4 x 1N400x diodes and a 1 ohm resistor, all in series. Measure voltage across the 1 ohm resistor, 1mV = 1mA. Drivers put out gibberish with no load. A 9V battery is at best marginal for a red laser. A pair of CR123's giving about 7.4 volts would work well with an LM317.

For your 250mA diode, if using an LM317, are you using a resistor of 5 ohms? Hook up your driver to the test load, and measure the mV's across the 1 ohm resistor in the test load to know your current. If OK, you can disconnect the test load and short the output cap, then solder on your LD. Unless you are planning on short duty cycles, the aixiz housing may not be enough of a heat sink.

EDIT : you posted the same minute I did, answering my questions for more info ...

 

[Cronie88]

Re: I need info on homemade burning lasers... can

Well, I tried the diode I got but there seems to be no current going through the diode, because it doesn't light up at all.
I just don't know what I am doing wrong.

I have 1 35v 47uf capacitor on the driver, two 10 ohm resistors, 1 potentiometer, 1 LM317T positive adjustable voltage regulator, 1 IN4001 micromini silicon diode, and a 9V battery to power it all.

please let me know what I need and what I do not need. 

 

[billg519]

Re: I need info on homemade burning lasers... can

Did you short the output cap before soldering the LD? If not, the cap may have instafried your LD !
I hope not ...

 

[Cronie88]

Re: I need info on homemade burning lasers... can

It is just the diode. there is no output cap on it. I think I might have fried the diode anyway. the only reason I say that is because the diode doesn't light at all.

 

[Cronie88]

Re: I need info on homemade burning lasers... can

thats ok though, because I have more, I just need to know what to do to the driver before I connect the other diode.

 

[Gazoo]

Re: I need info on homemade burning lasers... can

It is just the diode. there is no output cap on it. I think I might have fried the diode anyway. the only reason I say that is because the diode doesn't light at all.

You said and I quote "I have 1 35v 47uf capacitor on the driver," The question was did you short out the cap BEFORE you connected the diode. If not the cap would have at least 6 volts in it and it may have fried your diode. Normally, not always, when this happens the diode will still light as it has been turned into a beautiful LED.. ;D

Best thing to do is to hook up a dummy load to your driver and measure the current. It could be you made an error with your wiring and your diode might still be ok.

 

[Cronie88]

Re: I need info on homemade burning lasers... can

Nope, it still doesn't light. thats ok cuz I have another diode I can try. But this time I will discharge the cap. hopefully that will help. otherwise, I think I did fry the first diode. But, do you think that the battery is the right voltage or should I use a smaller voltage.

 

[Gazoo]

Re: I need info on homemade burning lasers... can

Nope, it still doesn't light. thats ok cuz I have another diode I can try. But this time I will discharge the cap. hopefully that will help. otherwise, I think I did fry the first diode. But, do you think that the battery is the right voltage or should I use a smaller voltage.

The battery is fine but those small 9volt batteries will sag quickly and not last long.

The current going to the diode will remain the same as long as the voltage is high enough so that the regulator doesn't drop out.

So the current will remain the same with anything between ~6 volts and the max the regulator can handle which is about 30 volts.

But the higher the voltage is the more the regulator will heat up.

The ideal battery configuration is 6 nimh batteries in series or a pair of lion batteries in series. Alkaline batteries are the worst because like I said they sag quickly and don't last long.

 

[Cronie88]

Re: I need info on homemade burning lasers... can

ok, well that info on the batteries I need is very helpful. Thanks.