20 watt laser driver.

Discussion in 'The Projects Forum' started by majorkuso, Jun 11, 2015.

  1. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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    I am wanting to drive a laser module rated at 20 watts 2 volt 10 amp peak. I have decided to use a pc power supply to supply the voltage and possibly an lm317 any suggestions.
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,649
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    Hello,

    The LM317 will not work, as it has a maximum current of about 1.5 Amp.

    Bertus
     
  3. Bordodynov

    Active Member

    May 20, 2015
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    I advise you to use a DC-DC converter. The output voltage of 2.7 volts do (0.7 volts + voltage laser). Make the generator current operational amplifier, a powerful MOS transistor. Be sure to take care of the cooling of the laser and the transistor.
    The operational amplifier is powered 5 volts.
     
    Last edited: Jun 16, 2015
  4. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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    I was going to use a couple of power transistors to supply the current and let the lm317 regulate voltage.I could put a few in parallel to share current load.
     
  5. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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  6. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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    anybody?
     
  7. DickCappels

    Moderator

    Aug 21, 2008
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    Buck converters can be very efficient.

    Texas Instrument's Simple Switcher series makes it pretty easy. You can go to this URL and type in your specifications and see your choices.
    http://www.ti.com/ww/en/simple_switcher/

    You might also find some good deals on eBay or DealExtreme
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,156
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    From the Wiki

    Class IV
    Lasers in this class have output powers of more than 500 mW in the beam and may cause severe, permanent damage to eye or skin without being magnified by optics of eye or instrumentation. Diffuse reflections of the laser beam can be hazardous to skin or eye within the Nominal Hazard Zone. Many industrial, scientific, military and medical lasers are in this category. Many handheld lasers ("laser pointers") at this output level are now available in this category.​

    Just sayin'
     
  9. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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    I have filter goggles and am running it in a fiber optic channel.
     
  10. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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    I would really like a through hole solution if possible
     
  11. majorkuso

    Thread Starter Active Member

    Aug 21, 2009
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    I would really like a through hole solution if possible
     
  12. Bordodynov

    Active Member

    May 20, 2015
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    Last edited: Jun 16, 2015
  13. wayneh

    Expert

    Sep 9, 2010
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    That's a nice converter but I believe you are aiming the wrong way. You don't need controlled voltage, you need controlled current. The controller will voltage to vary slightly - maybe with ±0.5V or less - in order to maintain a fixed current. The intensity of the laser will be proportional to the supplied current.
     
  14. Bordodynov

    Active Member

    May 20, 2015
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    Offering a dc/dc converter
    I suggest using it in conjunction with the current generator.
    I did so with a laser power of 1W. Because voltage 4 - 7 volts I did 3 volts.
    The current generator consists of an operational amplifier, a power MOSFET,
    reference voltage source and a few resistors and capacitors.
    I ran the laser power by changing the pulse duty factor (duty cycle).
    If you need a fixed power (constant current)
    you can convert the voltage source to the current source.
    I did it for high power LEDs using chips monitor current.
     
  15. wayneh

    Expert

    Sep 9, 2010
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    Can you show majorkuso a schematic or block diagram? Personally, I don't think I understand your control scheme.
     
  16. Bordodynov

    Active Member

    May 20, 2015
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    Here's my idea, but the responsibility for it work, I am not. Use this circuit at your own risk. 10A_2V.png
     
    Last edited: Jun 19, 2015
  17. Bordodynov

    Active Member

    May 20, 2015
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    You can include the eight current generators. Each current generator consists of the LT1083 and resistor 1Ohm. 8currents.png
     
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