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Simple Way to Drive 3 volt Laser Module?

Discussion in 'General Electronics Chat' started by JonSea, Aug 31, 2017.

  1. JonSea

    JonSea Well-Known Member

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    I bought some cheap 3 volt laser line generator modules. My supplier was out of 5 volt units. I want to run them off a 5 volt USB power bank.

    The laser module draws 20mA at 3 volts. It seems lile just adding an LED in series drops about 2.2 volts, and if the laser module is happy with sligbtly less than 3 volts, I'll have a pretty simple solution.


    The reason for the laser line generator is interesting. When I was at pbysical therapy post knee replacement, I overheard my therapist talking to a gentlemen with Parkinsons Disease who was freezing in his gait. He'd take a step, then be unable to take the next step.

    I had heard years ago that projecting a laser line to give people suffering like a target for the next step worked well. I asked my therapist of this technique was still used. Yes, he said, and they wanted to try it, but with the cost of laser being over $200, they hadn't tried it yet.

    Crazy. i had just purchased a "good" line generator for 5 bucks. I quickly whipped something together for my next appointment. The feedback was my collection of parts really improved this guy's walking. Thst felt pretty good amd I made a second module to help another gentlrman.
     
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  2. Pommie

    Pommie Well-Known Member Most Helpful Member

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    With the crazy prices these days, why not use one of these. And well done on your initiative.

    Mike.
     
  3. JonSea

    JonSea Well-Known Member

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    Hmmm. I do have some DC-DC converter modules like Mike linked. It's almost) as cheap as an LED. Thanks for the reminder.
     
  4. dave

    Dave New Member

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  5. Reloadron

    Reloadron Well-Known Member Most Helpful Member

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    With that in mind 5 volts - 3 volts = 2 volts / 20 mA = 100 Ohms. Just place a 100 Ohm current limiting resistor in series with your load (LASER). Wouldn't that work?

    Ron
     

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