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WarezWally

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I'm looking to put a 200mW red laser diode in a 2x AA flashlight. The setup is as follows:

Using 2x 1.5v AA batteries have the positive go to a 18 ohm resistor to limit the current to 166mA and connect that to the positive leg of the LD then connect the negative leg of the LD to the case.

Any problems with that?

Max voltage of the diode is 3v and the max currant is 270mW
 

WarezWally

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How so?

Voltage is a flat 3v, battery's are dead stable
Current is limited to below what the LD can handle

The only way I can see is dyeing if from heat

Ill have to get my magnifying glass and check the LD as I may have the wrong data sheet here
 

Archane

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The only way I can see is dyeing if from heat
Oh trust me that is not how it will die. The batteries do NOT output the same voltage/current consistantly. they jump around. when they are cold the output goes up by at least 10% and the first 1-2sec it's on it can be as high as 50%

so your 270ma current can peak as high as 350. which "can" be ok for diode but will increase your chances of killing the diode. now at VERY least put in a cap to each the spikes, this will not lower your voltage or current and will give your diode a chance at life.
 




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