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problem with my 200mW green laser

DoctorGalifrean

DoctorGalifrean

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Two days ago i spent the morning burning black tapes with my 200mW green laser pen. The next day it was weak, so i changed the batteries (new, from the same pack) but the beam didn't get stronger. I changed two pairs of new batteries, since that. Still nothing, so it doesn't burn anything anymore. .
What went wrong??
 
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Antimony Trioxide

Antimony Trioxide

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Sorry to be the bearer of bad news, but sounds like it burnt out. Whatever you do, don't look down the lens aperture where the laser comes out; even though there is no/little green light being emitted, there is still alot of harmful IR light radiating from the laser.
 
DoctorGalifrean

DoctorGalifrean

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Antimony Trioxide said:
Sorry to be the bearer of bad news, but sounds like it burnt out. Whatever you do, don't look down the lens aperture where the laser comes out; even though there is no/little green light being emitted, there is still alot of harmful IR light radiating from the laser.
Click to expand...

Thanks for the info. So, is it useless now?
Can i open the module and replace the diode with one taken from a DVD writer?
Some questions may be silly, but remember, I'm new to this!:undecided:
 
Antimony Trioxide

Antimony Trioxide

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You want to put a red diode into a green laser pen? I wouldn't call myself an expert on laser diodes and drivers, but I don't think 532nm green drivers are compatible with any other diode besides green. If you want to put a red diode in, you have to put a red diode driver. Maybe there's a driver in the CD burner. idk... maybe somebody else can confirm this.
 
Eudaimonium

Eudaimonium

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The original diode is suffering damage from being overdriven.
Eventually it will die.

Perhaps it was overheated too.

Now, first of all - there is no green diode.
There is IR 808nm diode in there, with a set of crystals to convert the light into green.

Look up DPSS system.

No, sorry, you cannot change the diode in there.
Even if you put the exact same type in there, you would still need to realign and glue the crystals you removed (so you can hammer the old diode out which is pressfited),
Which is next to impossible since those are alligned in microscopical precision.

Sorry dude.
Don't buy cheap el-crapo lasers.

First of all, not green 2x AAA pen is 200mW. EVAR. If one is advertised as such, then it's fake.

If you want techinical explanation, ask for it, but I doubt you will understand it.

Bottom line - it was never 200mW, and it was being overdriven. Or overheated.
 
DoctorGalifrean

DoctorGalifrean

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Eudaimonium said:
The original diode is suffering damage from being overdriven.
Eventually it will die.

Perhaps it was overheated too.

Now, first of all - there is no green diode.
There is IR 808nm diode in there, with a set of crystals to convert the light into green.

Look up DPSS system.

No, sorry, you cannot change the diode in there.
Even if you put the exact same type in there, you would still need to realign and glue the crystals you removed (so you can hammer the old diode out which is pressfited),
Which is next to impossible since those are alligned in microscopical precision.

Sorry dude.
Don't buy cheap el-crapo lasers.

First of all, not green 2x AAA pen is 200mW. EVAR. If one is advertised as such, then it's fake.

If you want techinical explanation, ask for it, but I doubt you will understand it.

Bottom line - it was never 200mW, and it was being overdriven. Or overheated.
Click to expand...

Thanks for the information! And yes, I would like some technical explanation, thank you.

Oh I took it out of its case and the pen was HOT to touch!!! It cooled only when I took the module out and turned the screw
to the right! Did it emit IR just by sitting there in tis case???

A photo of it.

2612-200mw1.jpg
 
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J

jfp999

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If it was hot, you probably over heated it and went over the duty cycle.
 
J

jfp999

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Then really crappy wiring allowed it to overheat easily or it WAS REALLY REALLY HOT. How long did you use it continuosly in one shot? More than 30 seconds on unknown brand is the standard.
 
HIMNL9

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have you checked with a DMM if the switch is not short-circuited, keeping it powered ?

Just a doubt .....
 
phoenix77

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Yeah, it sounds to me like you exceeded the duty cycle & fried the crystals inside. It might be possible to change out the module, if you can find one that fits. With unknown or real cheaply made lasers, you need to limit your usage to about 20 - 30 sec. MAX. Then allow about 60 sec. for a cool down, before using it again, otherwise, you'll have the same problem over & over. rob
 
Eudaimonium

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Technical explanation?
You got it!

The efficiency of the DPSS 532 nm laser system is typically 20%, therefore to achieve a 0.2 W output you need 1W of 808nm pump diode in there,
Efficiency of IR 808nm diodes are around 40-45% , hence the needed current to power 1W 808nm diode is 1.25 A, nominal amperage.

The power source for pen style lasers are AAA batts.

You are NOT getting 1.25 A out of AAA bat.
EVER.

Most you can draw is only around 700- maybe 800 mA at most.

Satisfied?
 
DoctorGalifrean

DoctorGalifrean

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Eudaimonium said:
Technical explanation?
You got it!

The efficiency of the DPSS 532 nm laser system is typically 20%, therefore to achieve a 0.2 W output you need 1W of 808nm pump diode in there,
Efficiency of IR 808nm diodes are around 40-45% , hence the needed current to power 1W 808nm diode is 1.25 A, nominal amperage.

The power source for pen style lasers are AAA batts.

You are NOT getting 1.25 A out of AAA bat.
EVER.

Most you can draw is only around 700- maybe 800 mA at most.

Satisfied?
Click to expand...

Actually yes... I'm an X-Ray Tech after all and i do know some things about electricity... And I really apreciate you explaining to me, and all of the other guys here with your information.
As for the time cycle, I never used it for more than 30 seconds BUT i never waited 60 seconds to use it again. So yes, i guess I misused the poor thing.
 
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