Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Problems with burnt out blue 2 Watt + laser

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
I recently bought a 2 watt laser diode on eBay and hooked it up with a driver consisting of one lm317t regulator and an ohm resistor. I hooked this up to 4 AA batteries and it burnt out in a week. It was a very powerful diode and costed $18 and I want to try again but don't want to waste my money. Any ideas?
 



paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
16,679
Points
113
The only 2+ watt laser diode is from the M140 projectors. An LM317 using a 1 ohm resistor should be fine to drive it as long as it is heat sunk well. You can push these diodes to 1.8 amps without problems if you heat sink it well too. I would use an SXD driver set to 1800 mA instead of an LM317 because it is more efficient and doesn't get anywhere as hot as that linear driver will. You will also need to use at least a 2 watt resistor with the LM317 and mount the IC to a heat sink.
 

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
The only 2+ watt laser diode is from the M140 projectors. An LM317 using a 1 ohm resistor should be fine to drive it as long as it is heat sunk well. You can push these diodes to 1.8 amps without problems if you heat sink it well too. I would use an SXD driver set to 1800 mA instead of an LM317 because it is more efficient and doesn't get anywhere as hot as that linear driver will. You will also need to use at least a 2 watt resistor with the LM317 and mount the IC to a heat sink.
Thanks is 6 volts too much of power?
 

Lifetime17

Well-known member
LPF Site Supporter
Joined
Dec 15, 2014
Messages
5,658
Points
113
Hi, With the SXD driver you can go up to 12V max , it also has a 2nd range , you need to bridge two resistor for that. These drivers are time proven and a Paul said the SXD is a better choice. heat sinking is of importance to keep the diode happy.
Rich:)
 

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
Thanks is 6 volts too much of power?
Also a sxd driver seems to pricey so would it be okay to risk it with my current driver
Hi, With the SXD driver you can go up to 12V max , it also has a 2nd range , you need to bridge two resistor for that. These drivers are time proven and a Paul said the SXD is a better choice. heat sinking is of importance to keep the diode happy.
Rich:)
So is there a way to get an SXD driver for cheaper than $30? I want to spend as little money as possible
 

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
16,679
Points
113
When he was active here I purchased my X-Drives directly from lazereer, but haven't been in touch for almost 3 years now. I suspect he is still making these drivers, but unless I want to buy several it isn't worth bothering him to get a discount. Since you don't know him I wouldn't expect to be able to even get a discount on several. I would just purchase one from DTR. There may be someone else selling these, but I can't say who off the top of my head.
 

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
Alright thanks so much for the help. This is my first burning laser project and I don't want to burn another $20 on a diode unless it'll work. I just wish there was another solution than buying a $30 driver
 

WizardG

Well-known member
LPF Site Supporter
Joined
May 9, 2011
Messages
753
Points
63
How well was the diode that died heat sinked? And how about the '317 regulator?
 

GSS

Well-known member
Joined
Apr 28, 2015
Messages
4,836
Points
113
If they are pen sized then you have to follow a very very short run cycle.
Thor type lasers are a bit bigger with more metal mass but still no more than 30 to 45 seconds on and off.
If your using a Axis module then its probably brass and they are plated silver color and brass isn't a good heatsink material. Even if you used a copper module you still needed to put it in a other sink. You can find a get me by heatsink sink on ebay for $3.
Like Wizard mentioned the 317 regulater should be attached to a AL plate for heatsinking also. I believe the overall lack of heatsinking was the issue.
 

Attachments

Last edited:

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
If they are pen sized then you have to follow a very very short run cycle.
Thor type lasers are a bit bigger with more metal mass but still no more than 30 to 45 seconds on and off.
If your using a Axis module then its probably brass and they are plated silver color and brass isn't a good heatsink material. Even if you used a copper module you still needed to put it in a other sink. You can find a get me by heatsink sink on ebay for $3.
Like Wizard mentioned the 317 regulater should be attached to a AL plate for heatsinking also. I believe the overall lack of heatsinking was the issue.
So if I purchase a heat sink for the laser diode will I be able to safely run it or will it risk burning out again. Also how would an AL plate properly sink an lm317
 

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
So if I purchase a heat sink for the laser diode will I be able to safely run it or will it risk burning out again. Also how would an AL plate properly sink an lm317
For some reason I just think that a simple heat sink wouldn't be able to prevent another diode from burning out but I am new to all of this
 

GSS

Well-known member
Joined
Apr 28, 2015
Messages
4,836
Points
113
So if I purchase a heat sink for the laser diode will I be able to safely run it or will it risk burning out again. Also how would an AL plate properly sink an lm317
Every bit of sinking helps. You won't be able to run the diode 100% constantly but alot more than just the little 12mm module its in.
Running a small fan over it helps alot also.. In believe the lm317's have a hole through them. You can just use a screw to mount them to any piece of aluminum stock you might have laying around "metal to metal contact" from a torn down computer or VCR or anything electrical thing basicly. A tapped hole would be ideal but i'm sure a self tapping screw would work some.
 

paul1598419

Well-known member
Joined
Sep 20, 2013
Messages
16,679
Points
113
That $3.50 heat sink won't be enough for run times above 30 seconds. I put all my M140 diodes into handheld hosts made from either aluminum or copper. The MS Envy is an aluminum host that I run for over a minute, but they are no longer available. A copper one would allow you to run it twice as long, but copper costs more. They make heat sinks specifically for ICs and transistors with the same case as the LM317. That I what I use for them. They have a greater surface area which helps dissipate the heat.
 

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
So if I were to buy a new 2 watt blue diode hook it to an lm317t regulator and two 3.3 ohm resistors and then put on a laser module and heat sink this laser would properly and safely work with 30 seconds of run time?
 

Jaxson Smit

Member
Joined
Dec 31, 2019
Messages
50
Points
8
So if I were to buy a new 2 watt blue diode hook it to an lm317t regulator and two 3.3 ohm resistors and then put on a laser module and heat sink this laser would properly and safely work with 30 seconds of run time?
(This is all being powered by a 4X AA battery pack)
 
Last edited:




Top