Problems with burnt out blue 2 Watt + laser

[Jaxson Smit]

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]

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]

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]

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]

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]

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]

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]

How well was the diode that died heat sinked? And how about the '317 regulator?

 

[Jaxson Smit]

How well was the diode that died heat sinked? And how about the '317 regulator?

I didn't hear sink them but how do other burning laser pens handle running with no heat sink

 

[GSS]

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.

 

[Jaxson Smit]

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]

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]

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]

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]

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]

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)