Old 01-09-2009, 03:17 PM #1
Junior Member
 
Join Date: Jan 2009
Posts: 2
Rep Power: 0
sniperpikachu is on a distinguished road
sniperpikachu sniperpikachu is offline
Junior Member
 
Join Date: Jan 2009
Posts: 2
Rep Power: 0
sniperpikachu is on a distinguished road
Default Plz Help, Red burning Laser problem

Hi, I would first like to introduce myself.
I have been reading this forum for a few weeks and I found that this forum is great and therefore I have registered an account.
I am a undergraduate E.E student in NY and I am current playing with laser diodes.

I would like to construct a simple burning laser by providing a constant current to a SONY SLD1236VL laser diode.

However, I have applied 250mA current and 5V voltage to the laser diode and it does not light up a match ( black).

I have been trying higher voltage and not dare to try higher current yet ;(

The spec. sheet said that it will give out 130mW to 150mW @ 200mA.

The circuit is attached to this topic.

Can anyone plz tell me what I have done wrong? Thank you.
Attached Thumbnails
Plz Help, Red burning Laser problem-1st_circuit-post.jpg  


sniperpikachu is offline   Reply With Quote


















Old 01-09-2009, 03:38 PM #2
daguin's Avatar
Class 4 Laser
 
Join Date: Mar 2008
Location: Sunny Southern California
Posts: 16,636
Rep Power: 556088
daguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond repute
daguin daguin is offline
Class 4 Laser
daguin's Avatar
 
Join Date: Mar 2008
Location: Sunny Southern California
Posts: 16,636
Rep Power: 556088
daguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond reputedaguin has a reputation beyond repute
Default Re: Plz Help, Red burning Laser problem

Quote:
Originally Posted by sniperpikachu
Hi, I would first like to introduce myself.
I have been reading this forum for a few weeks and I found that this forum is great and therefore I have registered an account.
I am a undergraduate E.E student in NY and I am current playing with laser diodes.
I would like to construct a simple burning laser by providing a constant current to a SONY SLD1236VL laser diode.
However, I have applied 250mA current and 5V voltage to the laser diode and it does not light up a match ( black).
I have been trying higher voltage and not dare to try higher current yet ;(
The spec. sheet said that it will give out 130mW to 150mW @ 200mA.
The circuit is attached to this topic.
Can anyone plz tell me what I have done wrong? Thank you. *
Have you actually measured the current?
Have you measured the output of the laser?
Do you have goggles?
What module/optics are you using?
Are you getting it focused down to a very small dot?
Are you holding the laser in your hand?

Peace,
dave
__________________
How To Get Along In and Be Accepted in the Forum

If you got some value out of reading this forum, how about donating $2 to keep it going?
Click Here to donate

Love all, trust a few, do wrong to none.
-William Shakespeare
daguin is offline   Reply With Quote
Old 01-09-2009, 04:13 PM #3
rog8811's Avatar
Class 3B Laser
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1252
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
rog8811 rog8811 is offline
Class 3B Laser
rog8811's Avatar
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1252
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
Default Re: Plz Help, Red burning Laser problem

The laser diode needs 3v, the regulator needs 3v, we reccomend a minimum input voltage of 7.2v for this combination.

Regards rog8811
__________________
See all of my videos on Vimeo
http://www.vimeo.com/4454150

Lots of tutorials and information on lasers
http://www.rog8811.com/

In the land of the blind the one eyed man..... is most likely holding the laser
rog8811 is offline   Reply With Quote
Old 01-09-2009, 04:29 PM #4
Junior Member
 
Join Date: Jan 2009
Posts: 2
Rep Power: 0
sniperpikachu is on a distinguished road
sniperpikachu sniperpikachu is offline
Junior Member
 
Join Date: Jan 2009
Posts: 2
Rep Power: 0
sniperpikachu is on a distinguished road
Default Re: Plz Help, Red burning Laser problem

Have you actually measured the current?
Well...actually the DMM I have can measure up to 200mA only.
I have a reading over 200mA and I assume it is 250mA.
I am planning to get a better DMM soon.

Have you measured the output of the laser?
I do not have anything that can measure the radiation power of the laser.
I only know the current regulator circuit gives 5V to the laser.
When the laser diode was turned on, I have measured 2.61V across the laser diode.

Do you have goggles?
I dont have googles but I didnt look into the laser. 8-)

What module/optics are you using?
I got the module from ebay.
I cant post link since I don have 10 post. I will attach the pohto.

Are you getting it focused down to a very small dot?
yes I did, and it suppose to be all the energy focused on the very small dot.

Are you holding the laser in your hand?
Well, I have tried holding and not holding it.
When I was not holding it, I put it on a heat sink I got from my old computer.


>>rog8811
I just measured, when input voltage is 9V battery, voltage across the laser diode is 2.4V.
when the input voltage is 5.3V, the voltage across the diode is 2.6V

I think I will try incressing the R in the regulator, then put a paralle resistor( according to Ohms Law it will get more the 3V, and divide the current to bias the diode is around 150mA)
I am going to find the resistor values and try it.

Thanks guys.
Attached Thumbnails
Plz Help, Red burning Laser problem-untitled_009.jpg  
sniperpikachu is offline   Reply With Quote
Old 01-09-2009, 04:40 PM #5
rog8811's Avatar
Class 3B Laser
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1252
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
rog8811 rog8811 is offline
Class 3B Laser
rog8811's Avatar
 
Join Date: Jul 2007
Location: Berkshire UK
Posts: 2,749
Rep Power: 1252
rog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond reputerog8811 has a reputation beyond repute
Default Re: Plz Help, Red burning Laser problem

Quote:
I just measured, when input voltage is 9V battery, voltage across the laser diode is 2.4V.
The important thing is the ma, the drive circuit is designed to give constant current, the voltage takes care of itself. if your meter only goes up to 200ma put a 1ohm resistor in series with the LD and measure the voltage drop across it, mv = ma with 1ohm.

Regards rog8811
Attached Thumbnails
Plz Help, Red burning Laser problem-measure_ma_01_001.jpg  
__________________
See all of my videos on Vimeo
http://www.vimeo.com/4454150

Lots of tutorials and information on lasers
http://www.rog8811.com/

In the land of the blind the one eyed man..... is most likely holding the laser
rog8811 is offline   Reply With Quote
Old 01-09-2009, 05:16 PM #6
Class 4 Laser
 
Join Date: Nov 2008
Posts: 5,728
Rep Power: 3030
ElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond repute
ElektroFreak ElektroFreak is offline
Class 4 Laser
 
Join Date: Nov 2008
Posts: 5,728
Rep Power: 3030
ElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond reputeElektroFreak has a reputation beyond repute
Default Re: Plz Help, Red burning Laser problem

With the driver you are using, you can measure the current directly between the battery and the driver instead of between the driver and the diode. This is a MUCH safer way to do it, and the reading will be the same either way. This will only work on linear drivers like the "DDL" LM317 circuit you are using.
__________________
Laser Resources (for n00bs and veterans alike!)

Sam's Laser FAQ (The Laser Bible)

http://www.repairfaq.org/sam/laserfaq.htm

RP Photonics Encyclopedia of Laser Physics and Technology

http://www.rp-photonics.com/encyclopedia.html

ULTIMATE DIY PROJECTOR REFERENCE

http://nqlasers.com/scannerreference...itle=Main_Page

SUCCESS is the best revenge.
ElektroFreak is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



























Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 04:49 PM.


Powered by: vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC