im using LG 20x DVD burner diode, please help!

guys do you have an idea how can i ran IR LD using 3 AAA (4.5v), what is the recommended resistor? do i have to put some caps and a diode? please give me suggestion on this, thanks.

You'd still need to put a capacitor on it, as for the current I suggest you put 130mA in it since phenol said his first one died at 150A and he's currently driving the other at 140mA. DON'T MESS AROUND WITH IT ANYMORE, I DON'T TRUST IR SINCE IT CAN REFLECT OFF SOME THINGS VISIBLE LIGHT WOULDN'T, IT ALSO SEES SOME THINGS TRANSPARENT LIKE COKE, GET SOME GOGGLES FIRST. Here's two GBs for IR, red, green, and blue goggles:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1199489380/45
http://www.laserpointerforums.com/forums/YaBB.pl?num=1196394222

ok that's great chido, can you give me some idea how can i setup, to drive the IR LD using 4.5v input, thanks. if you have schematics, thats great.

The only way to drive it off a 4.5v input would be if you used the AMC7135 driver which gazoo discussed on page 3 of this thread, otherwise you could just use a capacitor and a resistor to offer some protection, it's not nearly as good as a driver, but it'll make the diode live longer than running it directly from the batteries. I wouldn't really care since it's just an IR diode, but if you want it to live a really long time, use the AMC7135 driver.

ok what should be the value of capacitor and resistor? do i need to put diode for protection?

You can use the same kind of capacitor you used for the ddl driver, as for the resistor you can use a 9ohm, that would limit the current to 138mA. And you can include a diode too, but I don't think it's worth it since it's just for polarity protection.

ok thanks, il try that one this after noon,chido another one, what was the maximum current for that IR LD for good life? thanks.

Well phenol said his first one died at 150mA and he's currently running another one at 140mA. I'd suggest driving it at 130mA. Using the 9ohm resistor to limit the current to 138mA and then use a pot to bring it down to 130, or just use a 10ohm resistor with no pot which would limit it to 125mA. You can also ask phenol how long he's been driving his at 140mA, if he's getting good resuslts then you could just use the 9ohm with no pot. Just choose an option. ;D

If you can find the spec sheet for the IR diode, then you will be able to answer your own question. Whithout a spec sheet it is trial and error for any diode.

I really am not sure I would recommend the 7135 for use with the IR diode. It would take a pretty hefty resistor to absorb the 200+ ma's of excess current.

adgmeijin: You are asking a lot of questions which are easily answered by performing a few simple calculations. Following is going to be my 'Canned Response" from now on...lol

The LM317 is no mystery and very easy to work with. The following calculations always apply since it uses 1.25 volts for its reference voltage, and ohms's laws don't lie.

To calculate the resistor needed for a given current, take 1.25 and divide it by the current. So say you want to drive a SenKat diode with 250 ma's. 1.25 divided by .250 = a 5 ohm resistor.

Another way you could do this is to take 1.25 and divide it by the resistance. 1.25 divided by 5 = .250.

Next you will want to calculate the wattage of the resister needed. We know 1/2 watt resistors are common for use with the regulator. But to figure it out, simply take the 1.25 and multiply it times the current. 1.25 times .250 =.3125 watts.

The rule of thumb for the voltage going into the regulator is it should be 3 volts more than the voltage going to the diode. A SenKat diode running at 250ma's will have about 3 volts across it. Therefore a minimum if 6 volts is needed.
I recommend 6 nimh batteries or 2 RCR123's for use with Daedal's driver.

This is why you need at least 8 volts to run the blu-ray. You will find when you have it hooked up, the voltage across it will be appx. 5 volts. But since it will only draw ~38ma's, you can run it with a 9 volt battery.

To learn more about ohms law go here:

http://www.the12volt.com/ohm/ohmslaw.asp

Gazoo its fine with the LM317 im now running my blu-ray and DVD laser in a proper way, and the required voltage and current, all i want from now is a simple parts to drive IR LD using 4.5 volts input, i will search also the data sheet for IR LD , then i will inform you the result, thanks anyway..

hey phenol how long can you ran your IR LD @ 140ma, does it have a good results in it? do you think you can have its quality life? how do you ran your IR LD, do you use resistors only? what voltage are you using? i need some idea, thanks.

adgmeijin said:

hey phenol how long can you ran your IR LD @ 140ma, does it have a good results in it? do you think you can have its quality life? how do you ran your IR LD, do you use resistors only? what voltage are you using? i need some idea, thanks.

Click to expand...

i must admit that i was fiddling with the first LD, trying to adjust its position in the housing while it was powered at 150mA. I believe my soldering joints were fine and reliable and that there were no intermittent connections, which leads me to believe that the death cause was either too much current or some metal debris/specks of dirt entering the aperture of the LD.
The second one has been running at 140mA for a couple of months now. As i said before, i leave it on continuously and it doesnt get hot, not even warm. As i dont have a power meter at hand, i cant tell if there is degradation in performance.
I use the current source/or very similar/ described here:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1193741215/0
and a lab power supply, so voltage input is not a concern. If you insist on powering it from 4.5V batts, the circuit on page 3 of the upper link would work fine, down to about 3V...speaking of which, the simpler circuit on page 1 could also be moded to work with lower supply voltages.
If you want to to use a simple resistor 'driver' and 4.5V, for 140mA the resistance should be ~16.4ohms /for 2.2V across the laser diode/. You can calculate it as follows: R=(Ubatt-U[sub]LD[/sub])/I
Naturally, when the battery sags, so does the current.
Attached is a zip package with two typical CD burner IR LDs

thanks phenol, i try experimenting your guides, i hope that this may be a success to IR LD projects.

hey chido my IR LD is working well im using 3 rechargeable AAA and can be subtitute by 1 rechargeable CR123 instead of AAA's for input, i use 10ohm resistor and i put a capacitor between the IRLD pins for safety. thanks man, also to Phenol and Gazoo.

All right man, I hope your LD lives a long and happy life.
Now for god's sake please get some IR goggles so your eyes can also live a long and happy life. ;D

Oh, and how much current did you end up driving your open can diode with?