how to- make /source a proximty switch?

Hello JE in Chicago

Try a Capacitive Proximity Switch.

These are made with varying sensitivities, and are particularly suitable where a body part needs to be sensed without Optics, Infrared, or Mechanical Sensor type.

Refer here: http://www.globetron.com/capproxsw.html and http://www.globetron.com/capfilsen.html

Also refer here: http://sensors-transducers.globalspec.com/learnmore/sensors_transducers_detectors/proximity_presence_sensing/capacitive_proximity_sensors

And more here: http://www.ia.omron.com/product/48.html?gclid=CPKqu7-2rZUCFQv7agodpQVEkQ

These sensors are very robust, weather and waterproof etc, many operate from the standard Control Voltage of 24V DC, but you could check with suppliers for a 12 V DC unit, or alternatively, fit a small 12V DC to 24V DC Converter into your system.

Kind Regards....

There should be something on this site to do the job...or at least point you in the right direction....

http://www.lightcurtain.com/light_curtian-selection.html

Good Luck,

Roger

This might be interesting:-

http://www.pldesignline.com/showArticle.jhtml?articleID=210002959

Sparky, randall, rcl:

Its a home run!

Nice job guys.

milo

is this set of relays on a machine? what kind? the fact that the operators are wearing gloves make me think of a machine tool of some kind. do you require operators hands clear of mechanism before starting? there are a number of great switches/sensors for this from balluff (www.balluff.com) banner (www.banner-engineering.com) STI http://www.sti.com/products/ and a host of others Allen bradley (www.ab.com) square d (www.squared.com) also have the switches and all else you will need for anti tiedown / hands clear operation. if you are looking for a "bargain" solution take a look at all of the above mentioned and then go hunting on EBAY where you will find all that you need and then some at pennies on the dollar good luck