650nm dvd diode, what am i doing wronge

[zirakon]

Hi. guys.

I wonder what i am doing wronge. I've got a dvd burner diode, i
got a collimater lense, the diode is feeded at 400mA around 2.2v
and even there, there is no smoke in the focused spot. hummmm
Does it have somthing to do with the diode type. Its is the type
with closed housing ( with a little glass cover over the semiconductor)...
Or do i have to pulsed it????hummmmm

Can any one help.

Regards John:cryyy:

 

[Eudaimonium]

What kind of driver are you using?
Please post some pictures of your setup.

You do not call your doctor asking for help, you must show him the situation so he can help you.
Same here.
You have to show us what have you made.
Please take detailed pics of your entire setup, and we can help you.

 

[zirakon]

Sorry i have no camera in reach. But i am using a labratory powersupply with current limiter.
i have ajusted the current limit to 400mA. ( 5v ).
The collimator lense is from a simple pointer.
When it is powered the spot is realy bright, more than a 5mw pointer.
I have tryed to point at paper plastic foam, but no smoke.
I have just ordered a new 5mw laserpointer , to check if it is the collimator lense.
I will try to get a camera and take some shots.

RGD John

 

[Eudaimonium]

Sorry i have no camera in reach. But i am using a labratory powersupply with current limiter.
i have ajusted the current limit to 400mA. ( 5v ).
The collimator lense is from a simple pointer.
When it is powered the spot is realy bright, more than a 5mw pointer.
I have tryed to point at paper plastic foam, but no smoke.
I have just ordered a new 5mw laserpointer , to check if it is the collimator lense.
I will try to get a camera and take some shots.

RGD John

Unfortunately, no pain = no gain

AixiZ
Or
Sure Laser Module Housing - 5mW laser diode included [Sure Electronics] - $2.92 : High Tech DealZ, Simplifying the LASER Hobby!

Driver is a wide field, boost converters (FlexDrive), linears (LM317 or LM1117) take your pick.

You cannot power a sensitive laser diode with equipement that is not meant to power it.

Once you build a driver for your laser diode which is mounted in a housing made for laser diode, you will see where you got wrong

Lack of heatsinking is resulting in very high shift of dynamic resistance of LD, lowering it's efficiency greatly, resulting in output getting as low as 1 mW , and even below lasing sometimes.
Also, lens from cheapies will cut off a good 50% of power overall.

 

[zirakon]

rgr.
i will build a driver with LM317, and see if this will help, and also be aware of the optics...

Thanks

John

 

[Eudaimonium]

rgr.
i will build a driver with LM317, and see if this will help, and also be aware of the optics...

Thanks

John

If 10pack aixiz bulk is too much for you,
feel more than free to buy from a great member here Kendall , I linked you his HIghTechDealz site.

LM317 is fairly the most simplest driver you can build, and works well,
Also, you can make it even more simple:
You do not need the rectifier diode in parralel with laser diode,
And also, you do not need parallel resitors and potenciometer between OUT and ADJ, except one single resistor.

To calculate that resistor value:
1.25 / desired current in A = resistance
So, if you want 400mA, you need 3.15 ohms I think,
But 3.3 ohms commonly found works VERY WELL.

Don't forget to double check your connections,
and good luck with your build! :beer:

 

[Greenmechanic]

Hi. guys.

I wonder what i am doing wronge. I've got a dvd burner diode, i
got a collimater lense, the diode is feeded at 400mA around 2.2v
and even there, there is no smoke in the focused spot. hummmm
Does it have somthing to do with the diode type. Its is the type
with closed housing ( with a little glass cover over the semiconductor)...
Or do i have to pulsed it????hummmmm

Can any one help.

Regards John:cryyy:

If this info. is correct, there is your problem. Your Vf should be higher then 2.2V.
More like 3.5 +- at 400mA
2.2V is more along the lines a 808nm (IR) would need.
Are you sure you did not buy a IR driver? Or a driver like this one, as this is all they will output.
http://o-like.com/index.php?main_page=product_info&cPath=4&products_id=15

 

[Eudaimonium]

If this info. is correct, there is your problem. Your Vf should be higher then 2.2V.
More like 3.5 +- at 400mA
2.2V is more along the lines a 808nm (IR) would need.
Are you sure you did not buy a IR driver? Or a driver like this one, as this is all they will output.
2pcs Constant current laser diode driver 80-500mA w/TTL [OLDD20] - $5.00 : O-Like, Quality Products, Great Prices

Nope, he said that he is using regulated bench supply.

Anyhow, the Vf of red laser diode goes around 3.2 V at 400mA I think , not quite high as 3.5 V. Feel free to correct me if I'm wrong, Greenmechanic :wave:

Well, after a proper laser driver is made and diode tested with it, then we will see what is wrong.

 

[Greenmechanic]

Nope, he said that he is using regulated bench supply.

Opps! My bad, I missed that.

Anyhow, the Vf of red laser diode goes around 3.2 V at 400mA I think , not quite high as 3.5 V. Feel free to correct me if I'm wrong, Greenmechanic

Yes, 3.2V is within range for 400mA, it depends on the LD. Most of the LD's I've seen, measure between 3.3V and 3.5V at that current. But I have seen as low as 3.1V. There seems to be a lot of difference in diodes.
Bottom line is 2.2V is to low. Needs to be at least 3.1V, IIHO
Here is a graph of current vs. Vf for the LOC
My measurements are almost always a little higher then this chart????

 

[Eudaimonium]

Opps! My bad, I missed that.

Yes, 3.2V is within range for 400mA, it depends on the LD. Most of the LD's I've seen, measure between 3.3V and 3.5V at that current. But I have seen as low as 3.1V. There seems to be a lot of difference in diodes.
Bottom line is 2.2V is to low. Needs to be at least 3.1V, IIHO
Here is a graph of current vs. Vf for the LOC
My measurements are almost always a little higher then this chart????

Well even when using a bench supply you usually just preset the current, voltage is autosensed, right? If it is the current source supply that is.

You cannot preset both can you?

I never measured Vf of laser diodes, only the current through dummy load or LD or drivers or both.
However, a lot of factors are there, for instance, higher the temperature - higher the Vf od the diode.
The plot could have been taken with diode mounted on 1kg alluminum heatink for testing, and you are maybe measuring when the diode is in plain Aixiz or other module.
Perhaps that makes a small difference you are reffering to.

Just 'perhaps'. Not neccesarely

 

[zirakon]

Yes.i am using, as i call it a labratory power supply Danica TPS 23B.( 2x30vdc 2amps +5vdc 3amps). Still i cant, see the diff. between using this powersupply preset to current limit 400mA and then LM317T setup current limitted to also 400mA... It does the same thing. Voltage dosent matter if it is set to 5 or 6 or 10v. What matters is the current, Ohms Law you know. And with regard to the Laser diode i have extracted from af DVD burner drive X16, i am not sure of the producent, but the color is red, super bright when reflecting at a pice of paper, much more than my 5mw red laserpointer. Still no smoke. If i had picked the wronge laser diode ( read diode ) it is under 1 mw, so i am sure i got hold of the correct diode in the dvd burner drive. Also the "read diode would have died in 1 uS. But i still have to try out my new collimator lense. I'll be back with my resault.
Regards John

 

[Eudaimonium]

Yes.i am using, as i call it a labratory power supply Danica TPS 23B.( 2x30vdc 2amps +5vdc 3amps). Still i cant, see the diff. between using this powersupply preset to current limit 400mA and then LM317T setup current limitted to also 400mA... It does the same thing. Voltage dosent matter if it is set to 5 or 6 or 10v. What matters is the current, Ohms Law you know. And with regard to the Laser diode i have extracted from af DVD burner drive X16, i am not sure of the producent, but the color is red, super bright when reflecting at a pice of paper, much more than my 5mw red laserpointer. Still no smoke. If i had picked the wronge laser diode ( read diode ) it is under 1 mw, so i am sure i got hold of the correct diode in the dvd burner drive. Also the "read diode would have died in 1 uS. But i still have to try out my new collimator lense. I'll be back with my resault.
Regards John

Possibly a diode defect on a window or something of that type, reducing it power greatly, coupled with your cheapo pointer 'housing' it sure makes it really underpowered.

Take off the lens, and see if there are any black smudges od dots on the oval red shape you should get.

 

[desslok]

If you aim at white paper it will reflect. Try aiming it at black pasticm black garbage works good too, start about a foot away then slowly move back.