The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • OMTech 60 W Laser: Replacement HV Power Supply

    The original HV power supply in the OMTech 60 W laser went casters-up just barely inside OMTech’s six month tube-and-supply warranty period. For the record, the laser controller reports this status info since mid-March:

    Laser Stats - replacement supply
    Laser Stats – replacement supply

    I think the Total job laser on time line says the power supply failed after firing the laser for a little over eight hours. The OMTech manual says the laser tube should last 1000 to 2000 hours (low vs high power), which suggests I should stock up on power supplies.

    Its replacement just arrived:

    OMTech replacement HV supply
    OMTech replacement HV supply

    It (bottom) seems to be a knockoff of the original ZYE Laser supply (top), with a similar model number and a “serial number” resembling a date from last year. All the connectors matched up, which isn’t too surprising.

    The three most interesting inputs:

    • L = controller’s active-low L-ON enable output
    • IN = controller’s PWM output
    • P = jumper to G (circuit ground) — not water flow sensor

    Also note the two AC power-line terminals directly adjacent to the TEST button, then consider insulation and stand-off distances before poking the button with your index finger.

    The power supply has a digital current meter, so I plotted output current against PWM input:

    Laser Power Supply - mA vs PWM - overview
    Laser Power Supply – mA vs PWM – overview

    Taking more points at the low end, with vertical bars indicating single-digit flicker on the meter:

    Laser Power Supply - mA vs PWM - 0 to 20 PWM
    Laser Power Supply – mA vs PWM – 0 to 20 PWM

    I have little reason to believe the meter reading indicates the true current with any accuracy and I know CO₂ laser output power does not scale linearly with the current.

    But it’s cutting again, which is a step in the right direction.