Proximity switches...NPN or PNP?

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jer7440
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Proximity switches...NPN or PNP?

Post by jer7440 »

Hello,

I'm working on a small router driven by a Centroid Acorn. I need to purchase some limit switches and I was going to use a proximity style switch for ease of mounting in my situation. I am confused by NPN and PNP and how that factors into NO or NC. Can someone tell me what I need?

Thanks!
Gary Campbell
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Re: Proximity switches...NPN or PNP?

Post by Gary Campbell »

Acorn requires a sinking signal for its inputs, so you need NPN switches. Either NO or NC. NC is usually preferred as they will signal a fault (usually) when defective or suffer from wire damage that opens the circuit. That said, the vast majority of under $50k routers use NO sensors.
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jer7440
Posts: 2
Joined: Tue Dec 08, 2020 11:33 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
CNC Control System Serial Number: 4017
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No

Re: Proximity switches...NPN or PNP?

Post by jer7440 »

Gary Campbell wrote: Fri May 28, 2021 10:15 am Acorn requires a sinking signal for its inputs, so you need NPN switches. Either NO or NC. NC is usually preferred as they will signal a fault (usually) when defective or suffer from wire damage that opens the circuit. That said, the vast majority of under $50k routers use NO sensors.
Thank you, Sir!
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