Laser Diodes reuse to work with my circuit?

Okay so I have created a Daedel driver circuit for my laser diode which s currently an 808nM 300mW IR diode. Now before i tested my diode i tried some LEDs in its place. I connected 2 1.5v LEDs in series, thus drawing 3v the same as what my laser diode needs. Now the LEDs work absolutely fine. As soon as I connect my laser diode, which i have purchase 3 of incase they were defective, nothing happens. Nothing even emits from the diode.
I am so frustrated. Why is this?
Okay before you say i just cant see it. I used the Infra-red function on my camera to remotely record the results so i didn't fry my eyes. Nothing turned up on the camera so i stuck my hand in front of the diode and nothing what so ever.
Help?

Leds will draw much less current than a 300mW laser diode, it could be that your circuit
is simply not providing enought current. Instead of an Led, try using a testload, it will
mimic a laser diode much better.

Ok im about to test that also. I noticed that when i turn the pot nothing happens as regards to LED brightness. Is there a problem with this pot or what?

Hmmm. The pot should, if the circuit is working correctly, raise or lower the brightness of the LEDs but as Gryphon says, the current required by your LEDs is likely below lasing threshold. You don't need to match the voltage of your laser diode BTW as the driver provides the voltage required by whatever is hooked up to it. If you have a multimeter you can connect this in series with your LEDs, (or even directly to the output without LEDs), or connect in series with the input of the driver as the input current more-or-less matches output in these linear drivers. The best way is with a dummy test load though as that method also works with buck/boost or boost only drivers.

How are you providing power?

Can you provide a photo of your circuit? This may help.

M

I got some of these and got frustrated quickly because using 2 AA's fried my diode before I knew what happened. Recently I got one of these diodes to work well enough to melt electrical tape by using the same AA's and a 2 ohm resistor. By the way you can reduce the resistance by connecting resistors in parallel. Also you can in fact see a slight amount of red light coming from these diodes when they are on, however it's significantly smarter to shine the diode at something and observe the light indirectly than to look at the diode directly.

Do not direct drive your diode in the way psi seeker 34 recommends! Even with a resistor! You cannot know what state of charge your batteries are in and normal AAs are liable to produce spikes on connection that no resistor will deal with. Plus, the forward voltage of these diodes is only around 1.8V, not 3V! Instant death!

psi, you clearly need to know a lot more. That advice is back to YouTube hacking! Do not offer it until you have read all you need to and, know and understand it. Don't make me have to correct you again please, that's twice, and on two important no-nos here! Restrain yourself.

Thanks,

M

True that direct driving laser diodes is the most sure-fire way to break a load of them so that only the few lucky ones that are above specs have a chance to survive. (if it don't work kipkay it and be sure it's broke for good)

:wtf: A common digital multi meter (DMM) will tell you exactly the charge your batteries have.

psi seeker 34 said:

True that direct driving laser diodes is the most sure-fire way to break a load of them so that only the few lucky ones that are above specs have a chance to survive. (if it don't work kipkay it and be sure it's broke for good)

:wtf: A common digital multi meter (DMM) will tell you exactly the charge your batteries have.

Click to expand...

So why mention it without specifying the danger then? If it wasn't advice then you shouldn't have posted at all as the OP was asking for help.

psi seeker 34 said:

True that direct driving laser diodes is the most sure-fire way to break a load of them so that only the few lucky ones that are above specs have a chance to survive. (if it don't work kipkay it and be sure it's broke for good)

:wtf: A common digital multi meter (DMM) will tell you exactly the charge your batteries have.

Click to expand...

This won't tell you a thing about the charge, 'under load', or give any indication as to the level of spike you may or may not get from the battery.


I won't argue with you psi, this is not your thread, or mine, so if you are not able to contribute then simply don't post in it.

M