[nemisladkiv]

Hi i just got some of these: https://www.ebay.com/itm/DC-5V-M12-N...oAAOSwJ-pZulBz

And they say 5v working power.

Do i still need the optocoupler for this? Or can i just wire it straight to the limit and gnd?

[john-100]

What breakout board or motion control do you want to connect the 5v proximity sensors to ?

why do you think you need a optocoupler ?


John

[Al_The_Man]

They don't mention whether open collector or includes a pull up resistor, either way you would need one, I assume that they are 5v for use with TTL logic or a micro-processor for e.g.
Al.

[nemisladkiv]

I have a cncrouterparts CNC, but with the mk3 USB controller from planetCNC.

Reasons why i thought so was that i could not find any documentation of anyone using the 5 volt sensors. And all i have seen have been 12v or up.

I am fairly new to all this. So..

[PlanetCNC]

Both open collector and TTL sensors should work well with PlanetCNC controllers.

[john-100]

Going by a photo of the mk3 USB controller
I expect its based on a CPU like the Atmel AVR or ARM Cortex used in versions of the Arduino

with no circuit to buffer protecting the TTL compatable inputs of the mk3 USB controller

Using the LJ12A3-4-Z/BX-5V has the advantage it can be powered by the +5V from the mk3 USB controller -
you will need to check the total load on the 5V output for the stepper driver inputs & proximity sensors


provided the NPN sensor outputs have true open collectoroutputs - with no pullup either inside the sensor or an external pull up resistor

you should be able to use sensors powered by a 6 to 36V as usually found on line



So far I have not found a data sheet
this is what I have found for the 5v proximity sensors - N/C NPN output
Attachment 431326


so the proximity sensors will act like the micro switches shown on page 18 of the mk3 USB controller manual
Attachment 431328


while its easier to have sensors with N/O NPN outputs in parallel

I prefer to use sensors with N/C PNP outputs connected in series
for control boards like the mk3 USB controller you can use a NPN transistor or an opto isolator
to convert the positive supply out from the PNP sensor outputs into a NPN switch to ground


with N/O switches the control will not detect a broken switch wire

with N/C switches the control will see a broken wire as a tripped limit switch


John