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Help for a DIY circuit

  1. Nov 6, 2007 #1
    Hello to all,

    I need to be able to power 10 laser pointers at the same time all running from one adapter. Each laser is normally powered by 3 LR44 batteries, wich are 1.5v each (I dunno how many amps). The DC adapter ill be using for the project is 6v and 500 mA. Is that enough? if not im sure i have another one around the house. So basically, I want to know if this adapter will do and what kind of resistor i need to add to the circuit(hopefully I only need one, it would stink to have to solder one for each laser). Is theres anything else you think i should add to make this work?

    Thx for the help

  2. jcsd
  3. Nov 6, 2007 #2
    ive taken one of those laser pointers and powered it from a rectified 300v transformer, also powered it from my phone battery charger, from what i can tell the input power makes no difference on the beam, i really dont know anything abt lasers but those were my own observations... just string em together and into your power supply is all i can think of. i really dont know though, should probably wait for someone who knows what they're talking abt to give you better advice
  4. Nov 6, 2007 #3


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    You do know that may a fairly dangerous device you're building there? One of those can damage your or someone elses eyes if used improperly. Seems to me, ten of them could cause significant, permanent damage with a mere flick in the wrong direction.

    Googling "LR44 battery current" turns up a reliable-ish .6mA.

    So your laser array, depending on how you wire it up, should take 4.5V @ 6mA - way below your powerpack's 500mA.
  5. Nov 6, 2007 #4
    what exactly are you doing anyway?
    Are you trying to make a laser system that you'd find in a club or something like that or what?
  6. Nov 7, 2007 #5
    Im am buidling this for my own fun. These lasers have a output of >1mW wich is not dangerous. i know someone who counted up to 30 shooting one of them in each eyes to prove a point(I DONT RECOMEND TO TO THIS) and he dosent see any black holes (yet). I want to know if the 4.5v is enought or do i have to get one thats equal to the amout of the voltage required for all the lasers (1.5x3)x10 = 45?? also, what kind of a resistor or capacitor will i need to have 6mA?

    thank you
    Last edited: Nov 8, 2007
  7. Nov 7, 2007 #6


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    What an idiot.
  8. Nov 7, 2007 #7
    lol.... idiot indeed..... and actually this friend of yours could have permanent damage to their eye's already and just not realise it, thats often the case with laser burned eyes, the damage is just not always in their direct line of sight so they cant tell but its still there...
    if you(or this person) ever notice what seems to be orbs or watermarks floating around when your staring at something distant off in he corner of your eye and you try tracking it but it moves with your eyes so you cant get a direct look at it that would be from damaging your eyes if not from lasers then from staring at the sun....
    and saying a 1mw laser is not dangerous is like saying the sun is not....
  9. Nov 8, 2007 #8
    Ok, enought about talking about how 1mW laser can make your head explode, does anyone here have enough knowledge to answer my questions???
    Last edited: Nov 8, 2007
  10. Nov 9, 2007 #9
    i think that should answer it doesnt it? i dont know much abt lasers but it seems to be as good an answer as any...

    i think you should just string em together in series and put em right into your power source, use one variable resistor to adjust the current to be sure you dont blow anything though. i dont know how your input may effect your result but from my own experiment i described earlier it doesnt have much effect...
  11. Nov 9, 2007 #10
    as ive mentioned i dont really know anything about lasers so dont take my word for it.
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