LED indicator

Discussion in 'General Electronics Chat' started by Roboz, Mar 6, 2015.

  1. Roboz

    Thread Starter New Member

    Mar 6, 2015
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    I need a simple way to get a LED to indicate when a 240V submersible pump is running, mounted on the weatherproof power outlet.
     
  2. #12

    Expert

    Nov 30, 2010
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    Much simpler to just buy a neon indicator.
    The rules of this website say we can't tell you to connect an LED directly to the mains power, so just buy something that is built for that job.
     
  3. Reloadron

    Active Member

    Jan 15, 2015
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    I happen to like these things. I believe DigiKey sells them for about $12 (USD). Another option is just to place a wall wart across the pump mains and let that drive a LED. Neither will tell you if the pump is actually moving water (case of a pump running dry). Just a matter of how elaborate you want to get with the pump.

    Ron
     
  4. Roboz

    Thread Starter New Member

    Mar 6, 2015
    3
    0
    Thanks #12, I should have thought about the mains voltage thing, but as I am a retired electrician its not an issue. Current sensing to indicate that the 1100W pump (on a float switch) is actually running, is what I need. A few loops doesn't seem to induce enough current to light a LED, but there must be a simple way.
     
  5. #12

    Expert

    Nov 30, 2010
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    It looks like Reloadron hit it on the first try. :cool:
     
  6. Roboz

    Thread Starter New Member

    Mar 6, 2015
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    Thanks Ron, a CT is certainly the way to go, I just need more details on how many turns etc, to make my own.
     
  7. #12

    Expert

    Nov 30, 2010
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    Wind 10 turns on a power line frequency toroid core with the current carrying conductor passing through the core and see what it sends through a 220 ohm resistor. Multiply the turns until you can send 0.01 amp through a 2.2 volt (red) LED.

    That's the long form of, "I don't know"...giving you a method.
    Still, you're going to find out current transformers are for sale because it's a giant PIB to wind your own.
     
    Reloadron likes this.
  8. Reloadron

    Active Member

    Jan 15, 2015
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    Yeah, at about $12 I opt to just buy a turn key solution. :) Then too, with patience and time you could roll your own.
    I also like Mike's approach of just getting an old wall wart and using it.

    Ron
     
  9. #12

    Expert

    Nov 30, 2010
    16,257
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    A little discussion here: A wall wart won't show current flow. Same mistake I made with the neon indicator.
     
  10. Reloadron

    Active Member

    Jan 15, 2015
    963
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    Absolutely, I agree and mentioned that. The thing with all these pump threads always comes down to how much do we want to know about the pump. Voltage going to the pump doesn't tell us if the pump is running, current to the pump is a good indicator the pump is running, well pretty good unless the pump is sitting there locked rotor (impeller) or the pump is running dry. The list of weird pump scenarios goes on and on. Pumps are just one of those things. :)

    Ron
     
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