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OMTech 60 W Laser: Revised Red-Dot Pointer Power

The OMTech 60 W laser has a 24 V + 5 V power supply for the stepper motors and, I had always assumed, the feeble LED strip light on the gantry:

OMTech 60W laser - OEM lighting
OMTech 60W laser – OEM lighting

The stepper motor driver settings, plus a few amps for the controller and suchlike, added up to something over 12 A, far more than the 24 V supply’s 6 A spec should produce. When I added the COB strip lights around the platform, I dropped a 24 V wall wart into the electronics bay to avoid abusing that poor supply:

OMTech 60W laser - COB LED strips
OMTech 60W laser – COB LED strips

For reasons to be described later, it’s now time to upgrade that 24 V power supply to a 15 A supply that’s been on the shelf for far too long. However, it does not have a 5 V output, so it’s also time to figure out how much 5 V power the laser really needs.

A quick measurement suggested the 5 V output delivered 20 mA to something. After convincing myself the multimeter was working and that the gantry LED strip was still lit, I finally tracked the wire pair to the red-dot pointer:

OMTech red dot pointer - polarizing filter installed
OMTech red dot pointer – polarizing filter installed

Yeah, a whole dual-output power supply for one red-dot laser module.

Conveniently, the KT332N controller has several 5 V outputs and the LIMIT terminal block even has a GND terminal on the other end:

KT332N Limit Terminals - OEM
KT332N Limit Terminals – OEM

Prying off the hot melt glue, extracting the red-dot pointer wiring from the raceway, crimping ferrules on a couple of jumpers, and deploying a pair of Wago connectors:

KT332N Limit Terminals - red dot wiring
KT332N Limit Terminals – red dot wiring

I am still not accustomed to the color code:

  • Black = signal
  • Brown = power
  • Blue = GND

But it’s like that and that’s the way it is.

The red dot lit right up, the gantry LED strip obviously uses 24 V power, and I must shoehorn a slightly larger 24 V supply into the space currently occupied by the old supply.

Comments

2 responses to “OMTech 60 W Laser: Revised Red-Dot Pointer Power”

  1. tantris Avatar
    tantris

    Black = signal
    Brown = power
    Blue = GND

    I got the same color code on an inductive sensor from China. Must be a thing.

    1. Ed Avatar

      It might be a nod to the European AC power cord / wiring color code:

      https://en.wikipedia.org/wiki/Electrical_code#Post-harmonised_European_colours

      Black-for-signal still makes me flinch!

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