M140 & 405-G-2 Glass Lens Heatsink

[uMinded]

I am planning on picking up a 445nm M140 Diode In Copper Module With Leads & 405-G-2 Glass Lens from dtr-lpf and wondering what its maximum current limits are.

I plan on press fitting the module in a solid copper heatsink (from an old computer server) and having a pc fan blowing across the module and fins. I have used this with my constant current load and can maintain 5A loads with the copper only getting slightly warm.

I would like to drive the module at 2A to get ~2.5W out of it, during use the worst case will be on for 30min stretches and off for >1hr. Most of the time it will be duty cycled <100% current.

Will the solid copper cooling allow me to run it at 2A or will the internal junction temperature still be to great. For that point what is the max internal junction temperature and axis module coefficients so I could do a heatsink analysis?

 

[starlight]

Ask the guy you bought the diode from. He knows the currents better than probably anyone

 

[crazyspaz]

Scroll to the bottom of the page you bought the diode from...it has all the power tests. Also, instead of spending all that money on a G lens, get one of aixiz AR coared lenses, they are a fraction of the price.

 

[DTR]

2A is too much. Stick with 1.8A. If you want more power go with a 9mm 445 diode.:beer:

 

[uMinded]

Scroll to the bottom of the page you bought the diode from...it has all the power tests. Also, instead of spending all that money on a G lens, get one of aixiz AR coared lenses, they are a fraction of the price.

The page says higher output with the G2 lenses, the AR coated look like their to eliminate reflections. Why better and cheaper.

 

[crazyspaz]

The page says higher output with the G2 lenses, the AR coated look like their to eliminate reflections. Why better and cheaper.

Just different names, really. The G lenses are properly AR coated to allow significantly less optical loss than say, an uncoated lens. The lenses aixiz sell are darn near identical to the G lenses, but again, they are much cheaper.

 

[Livinloud]

I am planning on picking up a 445nm M140 Diode In Copper Module With Leads & 405-G-2 Glass Lens from dtr-lpf and wondering what its maximum current limits are.

I plan on press fitting the module in a solid copper heatsink (from an old computer server) and having a pc fan blowing across the module and fins. I have used this with my constant current load and can maintain 5A loads with the copper only getting slightly warm.

I would like to drive the module at 2A to get ~2.5W out of it, during use the worst case will be on for 30min stretches and off for >1hr. Most of the time it will be duty cycled <100% current.

Will the solid copper cooling allow me to run it at 2A or will the internal junction temperature still be to great. For that point what is the max internal junction temperature and axis module coefficients so I could do a heatsink analysis?

How did people miss this part? Its not going to happen......it just wont

 

[uMinded]

How did people miss this part? Its not going to happen......it just wont

What do you mean? If a LD spec says 1A@25c nominal with a 5,000hr life it should run for that long continued under those conditions. I'm guessing these LD's are being overdriven but with proper cooling they should last 50% their life at least.

 

[ARG]

What do you mean? If a LD spec says 1A@25c nominal with a 5,000hr life it should run for that long continued under those conditions. I'm guessing these LD's are being overdriven but with proper cooling they should last 50% their life at least.

That's not entirely the way it works. Double the current =/= half the life time.

The diode won't suddenly die. When abused at those currents for long periods of time (i.e. longer duty cycles than a handheld) the power of the diode will drop rapidly over time.
Even after a few hours of use the diode power will have dropped significantly, even with adequate cooling.
The reason it works in handhelds is that they are not on very often, so even though the diode power drops rapidly over time it is not very noticeable.

Your results may vary as diodes react differently when operated out of spec, but the end result will be similar. When operated within data sheet spec the diode power drop over time will be negligible.

There is a reason diodes in laser projectors & data projectors are run at lower currents. If you plan on using your diode with similar run times then you should use similar currents.

There's more information on this over at PL.