Maglight + dvdrom Diode ? True or False ?

Jenova

Enlightened
Joined
Oct 22, 2007
Messages
201
Hey guys new to the forums and just gettting into lasers
had a play with the normal red ones from bali :p
anyway used my mates green one (got it off ebay) so probley only a low mw

im sure alot of you have seen this
http://www.youtube.com/watch?v=CgJ0EpxjZBU&mode=related&search=

just wandering if its true and has anyone done it ??
looking to do it if its not a con
thanks
 

Kenom

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Joined
Apr 15, 2007
Messages
450
Location
Helena, Montana
sure it's true if you want to fry your laser diode. running straight of two batteries like that will most likely fry your diode. It's too much current.
 

Jenova

Enlightened
Joined
Oct 22, 2007
Messages
201
ahh k cool just come across it and though nice
anyway to mod it so it can still pop ballons but not fry the diode
 

RDZombie

Newly Enlightened
Joined
Sep 16, 2004
Messages
81
sure it's true if you want to fry your laser diode. running straight of two batteries like that will most likely fry your diode. It's too much current.


tru dat. slap the appropriate ballast resistor in series with the diode and youll be good to go
 

Jenova

Enlightened
Joined
Oct 22, 2007
Messages
201
ballast resistor?? isint that the main resistor when used to start a car ???
im guessing the size or type will depend on the type of diode ???
i sorta new to this stuff hey just want a kick *** maglite laser :p

anyone know what type ide need ive got a hp dvd burner im gonna strip
 

PhotonWrangler

Flashaholic
Joined
Oct 19, 2003
Messages
14,466
Location
In a handbasket
It's ohm's law. If you have three 1.5v batteries in series, you've got 4.5 volts across the diode. If the diode specs call for, say, 3 volts at 100ma to be in the middle of it's recommended operating range (above lasing threshold), you need to burn off 1.5 volts across the resistor. With .1 amp through the resistor, the resistor value is E/I (voltage over current), or 1.5/.1 = 15 ohms.

You also have to consider the wattage rating of the resistor. Using ohm's law for power (P=IxE) we have .1x1.5 = .15 watts, so a 15 ohm quarter-watt resistor will be barely enough (use a half-watt to be safe).

I've made some general assumptions here. Do a google search on the laser diode, get the operating current, look at your battery voltage and make your own calculations.

Good luck and be safe! You only get one set of eyes, and you can't get OEM replacements on them.
 
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