Maglight + dvdrom Diode ? True or False ?

[Jenova]

Hey guys new to the forums and just gettting into lasers
had a play with the normal red ones from bali
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]

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]

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]

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]

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

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

 

[PhotonWrangler]

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.