Anybody knows all about proximity switches?

Anybody knows all about proximity switches?
Please tell me some website where i can learn about them.
Searches on Google result in sites of manufacturers of proximity
switches and those sites cannot help my cause.
Please help.

 

Your question is very broad. You have IR, magnetic, radar, sonar,
capacitive, and other switches/sensors.

 

Please look at this web page:

http://www.topworx.com/ps_101.html

Is this helpful? If so, could you explain more about your application?
Your query is too vague to give less than an entire treatise as an
answer.

Cheeers
Chris