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Duty Cycle of Handheld Greenies?

Mptp

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I've read a lot that the main disadvantage of pens is that they have a duty cycle of only a couple of minutes, and that the handheld torches have a longer duty cycle, or none at all. But I couldn't find anywhere exactly what the duty cycle would be.
I have a 50mW O-Like green on the way, and I was wondering what sort of duty cycle I'd need to maintain to keep it in good shape.

Ta' =D
 





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Even torches have a duty cycle. Only a few that have TEC or forced Air cooling can maintain a 100% duty cycle. The internal heat builds up very fast and although there is more surface area to disperse the heat, it is still nowhere near efficient enough alone. I would not go over the 100/10 common suggested duty cycles on these units either, even if they can last a bit longer. This is of course only if you wish to achieve the maximum life of the laser, if >5000 hours or so is not a big deal you can run them longer but expect a reduced mttf.
 

Mptp

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I take 100/10 as 100 seconds on, 10 seconds off.

Thanks. =D
 

jayrob

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Keep in mind that these are 'cheap' green modules...

They are popular because they give a lot of power for a good price. Heatsinking is needed to help the module run stable. But either way, you should probably use a 1 min. on / 1 min. off duty cycle...
 
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IMO the sellers of these from China do not mention a duty/rest cycle so you will burn it up and buy another one from them.
 
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I have my 1st 50mW coming so my 2cents are worth just that. I have owned two Jasper 5mW green laser pointers and although I never really had either on for more than a minute, there have been instances where I forgot to shut it off or the button got hit in my pocket and it was left on for a looong time and was still burning. This may be typical with 5mW models but I have only owned Jasper models.Their models have buttons you use like and on/off switch and they claim they can do that because it doesn't need a cooldown. Could be a sales gimmick but mine never failed from being left on. Did I probably shorten the projected 5000 hour life? Maybe but what are the odds I'd keep it that long? Anyway, if you're asking about pointers over 5mW, than I guess my 2cents aren't worth jack!
 
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You got lucky and likely did reduce the mttf of the laser diode. It's the pump LD that overheats quickly and where most of the heat is generated. Even a 5mW green laser has a 200-250mW pump laser diode driving the crystals to produce the green light.

Granted in 5mW models the 250mW LD is normally reduced in power so that the output of <5mW is maintained (unless ultra crappy crystals are being used), however in higher output pens, the LD is being run at its rated output (or over driven in some cases, with even more heat being generated)with the quality of the crystals determining the final output range of the green.
 
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Anyone tested those heatsinks that are available to slide a green pen style pointer into? How well do they work? I was told by an ebay seller that the 5mW green bottle-shaped pointer did not require a duty/rest cycle. True?? they use a CR2 batt. thanks for the any info on this.Hak
 




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