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Topic: inductive proximity sensor NPN NO (Read 2482 times) previous topic - next topic

I got some upward sensing inductive sensors for my mill and was wondering if anyone had tried using something like this in their projects and or might have some references.  to me the hardware setup is quite simple(or so i think) but rather than re-invent the wheel id love to see how other might hook this up along with some basic ref code.  These are quite cheap inductive sensors but seem to work quite well(well enough that ill use them on my cnc mill).my mill uses its own type of opto board which has some nice easy to connect ports with pull ups ect.

http://www.ebay.co.uk/itm/170854002270?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I did look around for some answers before posting but nothing specifically to this type of pre buit inductive sensor.
cheers
Adam

MarkT

That part number (TL-W5MC1) has specification in its datasheet that don't match the specs in that ebay listing.  It might be 10--30V supply rather than 6..36V.

In either case the pull-up resistor being built in is a problem - it will pull the output higher than 5V.   You will need to work out the value of that resistor and add a pull-down to bring the output to a safe value (4.5V or so) when using the power source you've chosen.  Another fix would be a schottky diode between the output of the sensor and the +5V rail to prevent it rising above 5.3V or so.
[ I won't respond to messages, use the forum please ]

Mark I guess ill have to get hem to clarify if its 6 to 36v or not..but it also says that on the front of the sensor.  Ill get more of a chance to play with it the morning and update then.

Docedison

If you could find one, a linear transformer would be a better bet... The optical wheel type of counter is far more accurate though and is easier maintained in a shop environment, I should think for measuring distance. For proximity hall devices work well as do various types of "Optical Interrupters" and independent turns/servo counting (pulses to/from the motor for a stepper type of actuator. many different kinds of measurements. You didn't see where you stated you application or issue.

Doc
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Actually I just wanted to use Arduino to have a look at the output of the sensor.  I''m using these on my mill as home limit switches which they are perfect for.  I have on my mill a proper break out board that this sensor hooks directly up to without the need of any pull ups as they are built into it(into the board not the sensor).  I'm making robots with the mill so I was thinking these could also act as emergency stops to some of the larger arms and legs I'm making.  The legs Im using have optical rotary sensors but hey sometimes things come loose/break and these would add that extra sensing option to stop a crash. 

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