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# Help finding MW

#### blaize9

##### New member
the diode im useing is 400mA i want to find out how much mW it can produce i know that volts X mA = mW
here is what i did 9 X .4 = 3.6 W
3.6 W = 3600 mW :thinking:
on the web sight it says 220-250mw there is a big difference btween 3600 mW and 235 mW
What did i do wrong Sorry but im new to this kind of stuff :worthy:
Thanks, blaize9

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#### Greendream

##### New member
You can't calculate the output like that. Lasers are not 100% efficient, and individual lasers of the same kind can vary in their output.

To find out how many mW your laser is outputing, you need to measure the output with an LPM (Laser Power Meter) that is properly calibrated, and under strict test conditions if you want it to be very accurate.

If you search the word "laserbee" on here you should find what you are looking for.

#### blaize9

##### New member
thanks but i dont rlly need it

#### pseudolobster

##### New member
I have a car. If I press the gas pedal down half way how fast am I going?

It depends on a million different variables, the ambient temperature, the individual diode's efficiency, the type of lens, the amount of dust on the lens, etc etc etc.

If you don't have a laser power meter you can only guess. You've already been an estimate of 220mW to 250mW, which is the best anyone can do without an LPM.

Your calculation might be valid if lasers were 100% efficient, but nothing is. You may notice it heats up, and of course that heat has to come from somewhere.

#### blaize9

##### New member
as i said this is like my first time to deal with this kind of stuff
PLZ STOP POSTING UNLESS ITS IMPORTANT MY QUESTION WAS ANSWERED!

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#### Arenared

##### Banned
in that case take the advice and (like) learn from it.

#### blaize9

##### New member
looks like i learned some thing new today :beer:

#### lasersbee

##### Well-known member
as i said this is like my first time to deal with this kind of stuff
PLZ STOP POSTING UNLESS ITS IMPORTANT MY QUESTION WAS ANSWERED!
As a matter of fact... since you are new here.... I thought I'd let
you know....
Any Member can post anytime they want whether it is important to
you or not...

See... I just posted and it had nothing to do with your question...

Jerry

#### blaize9

##### New member
people should respect what other people say but if its off topic then keep it to yourself.
As a matter of fact... since you are new here.... I thought I'd let
you know....
Any Member can post anytime they want whether it is important to
you or not...

See... I just posted and it had nothing to do with your question...

Jerry[/QUOTE

#### lasersbee

##### Well-known member
Hey blaize9... If you don't want us to reply to your posts..
then simply don't post... or dictate to us what we can or
can't do...
Once you post anything on this Forum it is open to all members...
I guess you didn't understand what I posted above...

Jerry

#### blaize9

##### New member
I do understand but what im trying to say to every one who posts on this post dont go off topic

#### mfo

##### Banned
I do understand but what im trying to say to every one who posts on this post dont go off topic
Hey, don't talk to Jerry like that! He's a very well respected member of this forum. And for your information, no one here went off topic. You wanted to know how to calculate the power output of your laser, and you were told how to do so. If you don't like the answer, then go kick rocks.

Hey blaize9... If you don't want us to reply to your posts..
then simply don't post... or dictate to us what we can or
can't do...
Once you post anything on this Forum it is open to all members...
I guess you didn't understand what I posted above...

Jerry
You tell em'!

#### blaize9

##### New member
i was talking to every one not just him because on other forms there is alot of off topic posts and that makes me slightly mad
Hey, don't talk to Jerry like that! He's a very well respected member of this forum. And for your information, no one here went off topic. You wanted to know how to calculate the power output of your laser, and you were told how to do so. If you don't like the answer, then go kick rocks.

You tell em'!

#### mfo

##### Banned
i was talking to every one not just him because on other forms there is alot of off topic posts and that makes me slightly mad
Well no one went off topic so you should relax.

#### Mohrenberg

##### New member
blaize9, lobster and greendream both answered your question, and nobody went off topic unless you lashed out at them.