Proximity sensor vs Mechanical limit switch

[Sliven]

I have an application of using a servomotor for testing of Dimmer switch. To prevent turning of the motor shaft a full revolution a need to use a kind of sensor for safety purpose. The choice of Proximity sensor vs Mechanical limit switch?
Sliven

 

[MadMango]

I'm assuming you are doing some life cycle testing of these dimmer switches. Personally I would use a mechanical limit switch. They are cheap and easy to work with, and you have a low operating cycle. If the total cycles you are testing to are very high, it might be better to go with a proximity switch, as you won't have any wearing to worry about. "Happy the Hare at morning for she is ignorant to the Hunter's waking thoughts."

 

[jjellin]

Another option is to use a photomicrosensor. These work great for sensing whether there is something infront of it or not (5-20 mm away). They come in all different shapes and sizes. Some are reflective and some are through beam (transmissive)...and there are many more. The reflective ones will shine a light (I believe its in the infrared spectrum) and when it bounces off a nearby onject it detects it. The through beam is the same except it detects when you've broken the beam. These devices are small and very effective.

The reflective once are best used on a shiny surface, but we have used them on dark, dull plastics. The through beam just need to be set up so a flag passes through the beam.

Go to

http://oeiweb.omron.com/oei/

and search for photmicrosensors...we used the amplified type (both transmissive and reflective)...but take a look around. Specifically check out ones like ee-spy411 or ee-spx403

good luck