MXDL Question

[amkdeath]

so, if I dont change the resistor soon, Ill kill my diode...


I dont have my RMA DMM yet, so that could be a problem...

according to this:

I've posted several times about graphing your diode I(current) vs P output to find the knee of the curve. This is one way to find where your LD is crapping out and will give you no more. Beating the LD with current until output improves doesn't hold here.
I graphed two diodes today with my TEC cooled module. I did this by hand using my LPM-1 power meter in 50 mA steps.
The lower curve is a SenKat GB diode and the higher one is an open can harvested from a 20x DVD. Note the differences !! The GB is more efficient up to about 200 mW but the open can has a poorer efficiency slope up to 300 mW.

I hope this graph comes through OK. It shows where to back off !!! Every LD is a little different and will have a different curve by a little bit.

Mike

(there is a pic on that page) I am getting 300mW from my diode? COOL i could use that heatsink soon, Ill have to get my card fixed 2morrow...

also, according to the graph on that page, 520 is the peak of the curve... which is 300mW

 

[jayrob]

Here's an interactive site for determining resistor color codes: http://samengstrom.com/nxl/3660/4_band_resistor_color_code_page.en.html

knimrod, that's a great link! If my resistor in question was red/black/gold/gold, it would be only 2 ohms. Which would be 625mA. Since I am getting 421mA, it has to be orange/black/gold/gold. Thanks for sharing that...

Gazoo, I know you were only just warning me to double check it. I appreciate that very much! I don't need to loose any more diodes! Lol...
Jay

 

[Gazoo]

Jay,
I know you don't need to lose any more diodes, the one you lost is the same as loosing 10 open cans.... :'( I am going to order some 3 ohm resistors. I could probably find some combination of resistors here that would work, but I like using only one resistor when possible and the space on the MXDL board is limited.

amkdeath, I am getting a good 250mw's out of an open can running at 350ma's. But this is with the Meredith module with the glass lens. If you are using an acrylic lens, I think you can expect a hair more than 250mw's running at 420ma's.

 

[TheMonk]

Jay,
I know you don't need to lose any more diodes, the one you lost is the same as loosing 10 open cans.... :'( I am going to order some 3 ohm resistors. I could probably find some combination of resistors here that would work, but I like using only one resistor when possible and the space on the MXDL board is limited.

amkdeath,  I am getting a good 250mw's out of an open can running at 350ma's. But this is with the Meredith module with the glass lens. If you are using an acrylic lens, I think you can expect a hair more than 250mw's running at 420ma's.

Gazoo, can you replace the acrylic lens with glass lens in the aixiz module and get the same results as using the Meredith module with glass lens? :

 

[amkdeath]

parallel resistor calculator:
http://www.1728.com/resistrs.htm


or you could do:

3=1/(1/x)+(1/y)

solve for x and y to get what 2 resistances you need, add variables untill you get your desired configuration

 

[amkdeath]

a 10, 33, and 5.1 ohm resistor in parallel = 3.0639ohms, which would give you around 408mA

I think ill just replace that resistor with 3 1ohms in sereis

(i happen to have a few 10ohm resistors, a few 5.1 hom resistors, a few 33 ohms, and a bunch of 1 ohm resistors lol)

regards,

amk

 

[amkdeath]

well, I took apart my laser, and I confirm the resistor IS orange black gold gold, meaning it is 3 homs with 5% tolerance

unless it is over the 5% range, and I have like 2.4ohms, my laser should be running at 420mA, I will check when I recieve my new DMM.

regards,

amk

 

[Gazoo]

Gazoo, can you replace the acrylic lens with glass lens in the aixiz module and get the same results as using the Meredith module with glass lens? :

I know you can with the smaller aixiz module. I haven't tried it yet with the regular aixiz module, but I would think so.

 

[Gazoo]

I should know better than to assume anything. I had assumed since one of my MXDL's had a 2.4 ohm resistor the other one would too. Well I took the other one apart and it is definitely a 3 ohm resistor.

 

[jayrob]

I should know better than to assume anything. I had assumed since one of my MXDL's had a 2.4 ohm resistor the other one would too. Well I took the other one apart and it is definitely a 3 ohm resistor.

That's strange that they use different resistors huh? Probably the same emitters?? Oh well, I guess I'm glad that they used different ones! Lol...because now, I learned some new things about how to understand the color stripes on the resistors!...
Jay

 

[Gazoo]

Yup, I am surprised by that as well. I should have compared the brightness between the two but I thought both lights would have the same resistor. Oh well, doesn't matter as I am very happy with the led mod.

Speaking of mods, I started my MXDL laser mod. I didn't have anything to chisel or grind out the top of the driver housing to make room for the driver. So I just took a dremel and cut the top part off...lol. I will use some glue on the threads to ensure over time it doesn't turn. Anyway, that's the latest update from me... ;D I hope to have it completed by no later than Tues.

Jay, your heatsink fits perfectly and I will for sure be ordering a couple more. Thanks...again...

 

[jayrob]

Great news Gazoo! A dremel is a great tool...I use mine quite often. Sounds like you have your 3 ohm resistor already... Looking forward to some pictures of your MXDL 300! Maybe even a new thread huh? I am also interested in your power measurements. They should be very similar to mine...
Jay

 

[Gazoo]

Jay I apologize as I don't have a good camera. As you know I will be building a couple more of these and do intend to take pics of one of the builds. I do promise I will post the readings from the LPM-1. I am getting curious about that too..lol. Hopefully it does turn out to be a MXDL 300.

 

[jayrob]

Jay I apologize as I don't have a good camera. As you know I will be building a couple more of these and do intend to take pics of one of the builds. I do promise I will post the readings from the LPM-1. I am getting curious about that too..lol. Hopefully it does turn out to be a MXDL 300.

No pics necessary...If you have a Meredith glass lens, and around 420mA, I am sure you will see 300mW with the open can! Well, I mean, I have seen this same measurement on two different open cans anyway... (thanks to you for helping me with this great set up) I really want to follow through with this blu-ray BURNER project. I have a couple of the PS3 diodes on the way as well. But, I am going to try maybe even a couple of high powered blu-ray diodes:

"Hi Will, it is interesting that you say that. Why would Sony lie about the diode specs for a 2 X Blu-ray burner? Well, that's besides the point. The answer to that will be found out at some future time. I would like to move forward with the testing of this 65mW, 405nm blu-ray diode you have for us! Now, since you cannot share the original spec sheet, I need to ask, have you tested the diodes with a power meter yet? I have the Andover Holography meter to test it with. From your 'copied' spec sheet, it looks like I should try it at 85mA (Typ.) up to 115mA (Max.). And should expect around 65mW @ 25 deg. C. (which seems like a rather low temp. threshold??) I guess what I am asking is, what if the diode is no where near the spec sheet? Or, if you have tested them, then I'm ok with that... I would expect, a brand new one to test myself. And I will share the test results with the forum to try and get a group buy going for these diodes. I am local to you. I live in Oakley, and work all around in the area. I would like to meet you personally to pay for and pick up the diode if possible. Please call me on my cell: 925-250-4680.
Thanks,
Jay
----- Original Message -----
From: Will Roberts
To: Jay Robertson
Sent: Sunday, February 03, 2008 3:48 PM
Subject: Re: My home e-mail- 405 nm laser diodes


sure $475.

I saw the link to the 445 nm diode spec.

There should be no drives with those diodes inside.

Will

Jay Robertson wrote:

Hi Will, sorry I didn't get back to sooner. I wanted to try a blu-ray diode harvest first:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1201654983/37#37
Man, I screwed up and wasted $300 bucks. Do you think you could sell me just one of the 'N' brand 65mW at $475 with the idea of sparking interest for more, when I do a thread in the forum on the build? People are very interested in getting a high power blu-ray diode for DIY lasers...
Jay
----- Original Message -----
From: Will Roberts
To: Jay Robertson
Cc: jayrob@inreach.com
Sent: Wednesday, January 30, 2008 9:05 AM
Subject: Re: My home e-mail- 405 nm laser diodes


Jay:
sorry it took so long.
Here are some prices.
I'll offere you 2 pcs at the 100 pcs price to get you going.

N brand 65 mW (80 mW max) 405 nm
single item: $699
10's $ 650
100 pcs $499
need to get price at 1K.

I can sell 50 at $ 525"

(my wife is going to kill me) There is something about the building of these lasers that is addicting! I mean, buying an RPL for an awesome laser is one thing, but building one is a whole different thing!...
Jay

 

[amkdeath]

i agree on the building thing jay

gazoo, I didnt chizel out the top, I didnt know that was practical. I used a drill to widen the hole so the LM317T fits through. all that is down there is the LM317T and a resistor, I dont know why ppl need so much space. the cap and rectifier on mine are on the diode itself.

also, I sorta killedthe provided pcb in the MXDL when I was playing around, so I had to solder wires from the bottom side to the top, an to the driver. I also had to solder the PCB to the case for -, cuz that screwed over too. it looks professionally done on the outside, but I laugh at my self when I look at the innards.

cant wait to get the heatsink and get this project done, after that is the DIY LPM project! YAY!

regards,

amk

 

[amkdeath]

[quote author=Gazoo link=1201570557/30#44 date=1202104332]Jay I apologize as I don't have a good camera. As you know I will be building a couple more of these and do intend to take pics of one of the builds. I do promise I will post the readings from the LPM-1. I am getting curious about that too..lol. Hopefully it does turn out to be a MXDL 300.

No pics necessary...If you have a Meredith glass lens, and around 420mA, I am sure you will see 300mW with the open can! Well, I mean, I have seen this same measurement on two different open cans anyway... (thanks to you for helping me with this great set up) I really want to follow through with this blu-ray BURNER project. I have a couple of the PS3 diodes on the way as well. But, I am going to try maybe even a couple of high powered blu-ray diodes:

"Hi Will, it is interesting that you say that. Why would Sony lie about the diode specs for a 2 X Blu-ray burner? Well, that's besides the point. The answer to that will be found out at some future time. I would like to move forward with the testing of this 65mW, 405nm blu-ray diode you have for us! Now, since you cannot share the original spec sheet, I need to ask, have you tested the diodes with a power meter yet? I have the Andover Holography meter to test it with. From your 'copied' spec sheet, it looks like I should try it at 85mA (Typ.) up to 115mA (Max.). And should expect around 65mW @ 25 deg. C. (which seems like a rather low temp. threshold??) I guess what I am asking is, what if the diode is no where near the spec sheet? Or, if you have tested them, then I'm ok with that... I would expect, a brand new one to test myself. And I will share the test results with the forum to try and get a group buy going for these diodes. I am local to you. I live in Oakley, and work all around in the area. I would like to meet you personally to pay for and pick up the diode if possible. Please call me on my cell: 925-250-4680.
Thanks,
Jay
----- Original Message -----
From: Will Roberts
To: Jay Robertson
Sent: Sunday, February 03, 2008 3:48 PM
Subject: Re: My home e-mail- 405 nm laser diodes


sure $475.

I saw the link to the 445 nm diode spec.

There should be no drives with those diodes inside.

Will

Jay Robertson wrote:

Hi Will, sorry I didn't get back to sooner. I wanted to try a blu-ray diode harvest first:
http://www.laserpointerforums.com/forums/YaBB.pl?num=1201654983/37#37
Man, I screwed up and wasted $300 bucks. Do you think you could sell me just one of the 'N' brand 65mW at $475 with the idea of sparking interest for more, when I do a thread in the forum on the build? People are very interested in getting a high power blu-ray diode for DIY lasers...
Jay
----- Original Message -----
From: Will Roberts
To: Jay Robertson
Cc: jayrob@inreach.com
Sent: Wednesday, January 30, 2008 9:05 AM
Subject: Re: My home e-mail- 405 nm laser diodes


Jay:
sorry it took so long.
Here are some prices.
I'll offere you 2 pcs at the 100 pcs price to get you going.

N brand 65 mW (80 mW max) 405 nm
single item: $699
10's $ 650
100 pcs $499
need to get price at 1K.

I can sell 50 at $ 525"

(my wife is going to kill me) There is something about the building of these lasers that is addicting! I mean, buying an RPL for an awesome laser is one thing, but building one is a whole different thing!...
Jay
[/quote]

wait so like 600 bucks a diode??? im out on that one...

LOL, mabe in like 20 or 30 years when blu-ray burneres are $20 a pop, we can start scavenging open can blurays from 20x blu-ray burners! ;D I know, let me dream....

regards,

amk