Adjustable analog laser driver for continuous 0-2A output

Discussion in 'Analog & Mixed-Signal Design' started by laserproject, Jun 11, 2018.

  1. laserproject

    Thread Starter New Member

    Jun 11, 2018
    3
    0
    I recently bought a 2W laser diode that I'm going to turn into a handheld laser pointer. It's obviously too powerful to just play around with at full strength, so I'd like to make an analog driver that I can use to dial it back to a safe(ish) 25mW. I purchased a cheap analog benchtop driver module, but it's not going to fit in any handheld laser and I don't have a good understanding of the circuit inside. Can someone help me spec/design an analog driver circuit that can run this monster diode? I want to be able to turn a knob to produce a continuous beam (non-pulsed, non-TTL) that can vary from 1-2% power up to 100%. I'm capable of soldering but I'm a mechanical engineer by trade, so the easier it is to understand, the better.

    Every analog laser resource I've found so far is all about getting smooth, high-frequency color gradients for professional multibeam projection equipment. I don't need any of that high-precision control, I'm just trying to make a big-ass laser pointer with a dimmer switch so I don't catch things on fire unless I intend to.

    ~EDIT~ Some info about the diodes:
    I have a $15 445nm diode for testing, and a $70 462nm for the final version.
    462nm response curve. (Initial lasing at 3.8V, 200mA. Max 1.8A @ 5.1V.)
    445nm only info supplied is 800mW output at 1A, current limit is 1.8A
     
    Last edited: Jun 11, 2018
  2. laserproject

    Thread Starter New Member

    Jun 11, 2018
    3
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    One other thing, I'd like to power the finished version with 3.7V Li-Ion batteries (18650) since I've already got some around, so I'll be working with a 7.4V or 11.1V DC power source.
     
  3. Bordodynov

    Well-Known Member

    May 20, 2015
    1,978
    596
    See
    2018-06-12_10-40-27.png
     
  4. Bordodynov

    Well-Known Member

    May 20, 2015
    1,978
    596
    See PLaser=F(iLaser) and VdropLaser=F(iLaser)
    2018-06-12_15-51-00.png
     
    laserproject likes this.
  5. laserproject

    Thread Starter New Member

    Jun 11, 2018
    3
    0
    WOW! This is way beyond anything I was expecting, Thank you!
     
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