10mw Red laser help

greenlaser

Newly Enlightened
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Apr 26, 2010
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Australia
hi guys im quite new to this stuff.
i need to do this for uni this year so i thought i better get cracking.
im about to buy some 10mw red laser diodes only thing is i need the driver so if anyone could show me a driver schematic it would be good. secondly can all lasers (blueray,greeen,red,1mw,5mw,30mw etc) will they all work with the same driver?
and thirdly will the red laser be powerful enough to have a visible beam and pop baloons as it is needed to display some of these qualities in the exam.
cheers
 
Easiest driver is one based on the LM317 in CC mode.

Check out laserpointerforums, they will probably suggest one of the drivers built by members there, but you should be able to find a good schematic for an LM317 driver. Search for DDL, Daedal, or LM317.

You can also get stronger diodes than 10mW, if you so desire. I got my LOC reds for about $9 each, and those are pretty powerful, capable of 150mW easily.

But yeah, check them out for info about the lasers. Check us out here at CPF for info about flashlights.
 
ok thanks for the help.
will 10mw burn?
is there a diference between cd burners dvd burners cd drives and dvd drive lasers? and what mw are they.
lastly if i make a driver with break away dil sokets will i be able to pull out the laser and attach another laser diode of another mw like switch the 10mw laser with a 50mw laser ?
cheers
 
I'll try to answer all of your questions -

...a driver schematic...

bshanahan14rulz is correct, something like the Daedal driver design would be one of the simplest. It is based on an LM317 regulator set-up in constant-current mode, with a current sense resistor placed in series between the output and the laser diode.

However...

...secondly can all lasers (blueray,greeen,red,1mw,5mw,30mw etc) will they all work with the same driver?...

It sounds like you need a pretty wide range, you may be better off getting an inexpensive commercial driver, perhaps something like a Rkcstr driver (Google it). That is somewhat similar in concept, but uses a lower drop-out voltage regulator (better than the LM317), and covers a wide output range.

However, like the LM317 designs, it is a LINEAR regulator, so you need to make sure your batteries can provide sufficient voltage for the laser diode in question, particularly if you try to use it with a laser that requires a higher voltage, such as a BluRay laser.

More specifically, your batteries has to be at LEAST 2.25V (driver overhead) + Voltage needed by laser diode, and less than 12V.

Yes, you can use the same driver for either Red or BluRay laser diodes, but the CURRENT has to be set to the proper value for the particular type & power of laser diode in question! Too little and it won't lase, too much and you burn it out! :eek:

And no, the same driver won't work for green. Green lasers don't use a green diode, they are a complex module which uses a multi-step process, and are driven by a high-power IR "pump" diode, which requires a special driver, and which is usually already built-in as part of the green module.

...if i make a driver with break away dil sokets will i be able to pull out the laser and attach another laser diode of another mw like switch the 10mw laser with a 50mw laser ?

No. As explained above, because of the different current requirements, you can't just "plug-and-play" different types/power levels of laser diodes.

...is there a diference between cd burners dvd burners cd drives and dvd drive lasers? and what mw are they...

I posted a detailed answer about this in another thread - I'll see if I can find it for you!

...will 10mw burn?...

No. Depending on the color, you'll need more like 10x-20x that power level for a good burner. The red laser diode from certain types of high-speed DVD burners can provide you with >250mw of red, see the other thread for details.

...and thirdly will the red laser be powerful enough to have a visible beam...

Unless you are using a beam enhancer like smoke or a fog machine, getting a visible red beam also requires pretty high power levels. If you want a visible beam, you are better off using a green laser. At the same power level, a green laser beam is much easier to see than either a red or BluRay - this is because human vision is much more sensitive to green light than it is to either red or violet.

...and pop baloons as it is needed to display some of these qualities in the exam.

I am a bit surprised, even at the college level, that your school is asking you do this without more guidance / supervision, as some of the things you want to do require laser power levels which are actually dangerous without proper safety equipment & precautions. Please check with you instructor before trying to build (or worse, demonstrate in a classroom full of unprotected students) a laser powerful enough to pop balloons & burn things! :eek:

10mw will not burn things or pop balloons, but is more in the safe-and-sane range than a high-power burner. Does your instructor REALLY want you to make a "death ray" - or is the extra horsepower your idea?
 
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