Need a sensor to create a revolution counter

Comments

• SRLM Posts: 5,045

  2009-04-17 23:20 edited 2009-04-17 23:20

  Is it rotational, or a needle that moves back and forth? You could have the needle break a IR beam if it rotates constantly. If it's a dial (like in a car) then you could probably hack into the wires that go to the gauge and use the signal directly. Some more information (picture too) would be helpful here.
  
  BTW, I like your icon. NWN is a great game...
• agregory Posts: 2

  2009-04-17 23:26 edited 2009-04-17 23:26

  I like the breaking an IR beam idea. Yes, it rotates 360 degrees and I want to count each revolution. Do you know a good part to use for that?
  
  Off topic NWN: I program my own module/server in my spare time. [noparse]:)[/noparse]
  
  Ah, a little looking in the sensor pages and I find:
  Item code 350-00017 for transmitting and
  Item code 350-00012 for receiving
  
  I'll look into these.
  
  Post Edited (agregory) : 4/17/2009 11:31:40 PM GMT
• SRLM Posts: 5,045

  2009-04-18 00:56 edited 2009-04-18 00:56

  Yep, those should work, assuming that the needle is thick enough to break the beam long enough to detect. If it's not, then you'll have to add something.
  
  You may also consider an inductor type rotary sensor. I'd don't really know all that much on the subject, but I believe that they sense the presence or absence of metal. It would probably be more weather resistant than an optical solution.
• W9GFO Posts: 4,010

  2009-04-18 05:06 edited 2009-04-18 05:06

  agregory said...
  I have a gas flow gauge that revolves and I'd like to detect each revolution with a sensor then display the count. I've looked at the Hall effect transistor but the magnets on this site are about 3/8" and the gauge needle is quite small so I'm not sure that would work to glue to the end of the needle. Anyone use a magnet on the order of 1-2 mm and had success with the Hall effect transistor? Anyone have a better idea? I don't want to attach anything large like a gear to the gauge because it looks fragile.

  
  I believe that the magnet is glued to the back of the hall sensor. The needle passing through, and altering the magnetic field would be detected by the hall sensor. The question then would be, would the needle sufficiently alter the magnetic field for the sensor to detect it?
  
  Rich H