500w 2v psu

Discussion in 'General Electronics Chat' started by Litch, Mar 23, 2014.

  1. Litch

    Thread Starter Member

    Jan 25, 2013
    86
    7
    Getting my hands on some 40W DPSS laser pumps for use in a DIY laser cutter machine. There are some power supplies out there, but they're "from china" and I'd firstly like it to last more than a day, and secondly to be able to accurately control the power output.

    For those who don't know what a Diode based laser is (as opposed to a gas chamber one) - these units only require between 0.2V and 2.0V but light power output is adjusted purely by current - for a 40W laser, current can be around 45A @ 1.8V (nominal); basically they're just super powered LEDs.

    The lasers are PWM friendly, so adjusting output to 1.8V (rated voltage) and building a basic SMPS without the smoothing capacitors may be a viable option.

    The main question is the transformer for the job... Unlikely I'll find a 600VA+ model with a 5v 1A (current feedback) and 1.8V secondary so I'll likely have to either get one custom made (expensive?) - or find an alternate method (Like bringing down a 5V model to 1.8V).

    Anyway - please comment, ideas are the game and thankyou in advance.

    [EDIT]

    I'd very much like to be able to control the power output via a PIC, as well as accurately measure the current via the same module - from the PIC to display I can do, my main concern is the mechanism for controlling current via the PIC (PWM driven FETs?).
     
    Last edited: Mar 23, 2014
  2. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    Rather than staring from scratch. High current 5V supplies are common. Both linear and switching. 50A <$50

    A voltage hack should be pretty simple. 5V to 3V out.
    If you can hack one for constant current it would be a good start.
    A constant current bench supply might be another option. I haven't found one under $500 though.:(

    Does it have to be efficient? Adding a constant current linear regulator to a low cost 5V/50A supply and dumping 30 watts is an option.
     
    Last edited: Mar 23, 2014
  3. Litch

    Thread Starter Member

    Jan 25, 2013
    86
    7
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