[kevincnc]

Can I use 10-30 volt N/C NPN prox sensors with the parallel port if I tie the computer 5V ground to my 24V ground?

Oops I meant FOR home/limits in the title.

[Al_The_Man]

If they are true Open Collector, you may get away with a 10k pull up from collector to PC 5v+.
Al.

[kevincnc]

If they are true Open Collector, you may get away with a 10k pull up from collector to PC 5v+.
Al.

Great, thanks!

[Crevice Reamer]

You could also use these $10 hall effect sensor/switches. Just need a little steel vane to slide through the slot and actuate. one wire for ground, one wire for +5 to 30V and one wire direct to open collector output. Nothing else needed.

Couldn't be easier.

I also use this for spindle speed sensor. They are not swarf sensitive, as the tiny magnet is internal and there is no detectable magnetism on the surface.

http://www.digikey.com/product-searc...3-ND&x=12&y=14

CR.

[Crevice Reamer]

Sorry! Forgot the link:
SR17C-J6 Honeywell Sensing and Control | 480-1993-ND | DigiKey

CR.

[kevincnc]

Sorry! Forgot the link:
SR17C-J6 Honeywell Sensing and Control | 480-1993-ND | DigiKey

CR.

Thanks, what kind of repeatability do you get with them?

[kevincnc]

Aren't those normally open? if so, I wouldn't use them for limits.

Edit: Or does this mean they would be N/C-

"•Operated by a "Ferrous Vane" interrupter for pulse counting or position sensing""

[Crevice Reamer]

Thanks, what kind of repeatability do you get with them?

They are electronic switches, with no moving parts, so extremely repeatable.

[Crevice Reamer]

Aren't those normally open? if so, I wouldn't use them for limits.

Edit: Or does this mean they would be N/C-

"•Operated by a "Ferrous Vane" interrupter for pulse counting or position sensing""

Yeah. I don't use limit switches. They are normally open so won't work for that. They make excellent home switches or sensors though.

CR.

[kevincnc]

Yeah. I don't use limit switches. They are normally open so won't work for that. They make excellent home switches or sensors though.

CR.

Okay, thanks anyway..I expect at least 1000 IPM so limit switches are going on :cheers:

[kevincnc]

I found a 4.8-30 VDC prox switch on the UK ebay site. Any reason this shouldn't work?

SN04-N 4mm Approach Sensor Inductive Proximity Switch NPN DC 4.8-30V 500mA | eBay

[Al_The_Man]

Looks like they should work?
Al.

[kevincnc]

Looks like they should work?
Al.

I think so too, and they're only $7.75 shipped. I'll order one to test.