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Limit switch

  1. Oct 26, 2004 #1
    Can someone explain to me how limit switch works in everday language, I got some sources that are too technical.

    Thank you,
  2. jcsd
  3. Oct 26, 2004 #2


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    Share the sources and maybe we can help.


  4. Oct 26, 2004 #3
    http://www.ab.com/sensors/products/limit_switches/ [Broken]

    I find it's not very easy to comprehend 100% the whole article
    Last edited by a moderator: May 1, 2017
  5. Oct 26, 2004 #4


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    The real difference between a "limit" switch and any other switch is that it is connected to a control function.
    In other words activation starts, stops or otherwise modifies some process.

    Your link is to a particular device that can be used for this function.
    There are other types using light, magnetism, pressure ect.
    You could take the light switch off your wall and use it as a limit switch.
  6. Oct 27, 2004 #5


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    It is simply a switch which is activated by something "hitting" it. There are many different types of limit switches.

    If you have a mechanism driven by a motor, it is very helpful to know when you have reached the end of your motion range. You can to this with a mechanical switch which is simply a micro switch with a arm attached. When your moving part compresses the arm the switch flips and turns off your motor (That is not the actual mechanism, but essentially what happens).

    There are also optical limit switches, for these you attach a "flag" to your moving part, the flag (a tab of metal) passes through the optical switch it blocks passage of light (the source is a LED) and trips the switch.

    Limit switches are on virtually all electro-mechanical mechanisms which involve movement of significantly massive parts. In modern equipment they are usually monitored by the software which is controlling the motion.
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