Duty Cycles Help

[mickatcol]

Ok, This is my first help post.

How do you workout the Duty Cycle of a Laser?

Lets say I had a Red (LPC-815) running at 360mA (220mw~) in a Aixiz module.
Then I take the same LPC-815 in a Aixiz module at 360mA and mount it in a Lab type heat sink.

What factors do I need to know, To workout a Duty Cycle?


Thanks


<--Mick-->

 

[Grix]

There are so many variables that you cannot know exactly. People just work out a rough estimate from the size of the heatsink to the current.

A LPC @ 360mA in a proper lab heatsink would have a very long duty cycle, you could leave it on for at least 10 minutes easily.

 

[mickatcol]

I want to use it in a Laser show.
So what would it take to run it say 1-2 hours.
Would it have to be TEC cooled?

I am going to be using analogue modulation for colour mixing, So its not going to be running at Full 360mA all the time.

I just don't want to cook it.

Thanks

 

[hugo999999]

in my opinion an lpc would be fine in a large heatsink with a fan, especially at 360ma

 

[Grix]

I would lower the current a tad just to be sure.

 

[mickatcol]

Ile just run it and see what happens.

Thanks

 

[rkcstr]

Nothing better than experimentation. Get your heatsink you want, put your laser together how you intend to use it, then turn it on and leave it go. Stick around for the first minute, see if the heatsink gets warm. If not, check back in another minute. If not, check back in a few minutes. Then 10 minutes, 20 minutes, etc. Depending on the size of your heatsink, after probably 10 minutes of being on, if it isn't hot, I doubt it will ever get warm unless you change variables like airflow, current, ambient temp, etc.

BTW, ideally, the heatsink should stay about room temp. Highest, slightly warm to the touch. That's probably conservative, but I would bet you your diode likely won't die for a very long time. If you're getting very warm with operation, either you need forced cooling (fan, TEC, etc) or just a bigger heatsink.