Please or Register to create posts and topics.

Limit switches - Induction Proximity Detectors SN04


My CO2 laser has inductive proximity detectors (SN04-N2) for the X and Y limit switches. These are powered from the 24Vdc supply and are normally closed switches with an open voltage of 12Vdc and a closed voltage of 0.7Vdc. I was loathed to connect them up to the mini gerbil as-is as I can't find any information about the voltage limits for the X/Y limit inputs and I can't see any opto-isolators.

Will these work without damaging the mini gerbil board? What is the input voltage range expected by the limit switch inputs?

The current M2 controller seems to be designed to cope with these proximity switches.

Nothing specific found relating to the voltage range for limit switches in my search of the forum.


Uploaded files:
  • IMG_3965.jpeg

I tried adding a potential divider to the output to adjust the high voltage to +5Vdc which worked fine on the bench but when connecting to the MiniGerbel the voltage levels were incorrect - no doubt something to do with the on board components.

At that point I decided to take the easy path and replaced the inductive proximity detectors with levered microswitches. Problem solved. 

My 600x400 mm laser now has a new controller and I can use LightBurn. I'm looking forward to getting restarted with the new configuration. No more Inkscape, k40Whisperer and timeouts (I hope).

Forum Registration