Swimming pool automatic level sensing circuit

Discussion in 'The Projects Forum' started by poolguy, May 26, 2010.

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  1. poolguy

    Thread Starter New Member

    May 26, 2010
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    I am trying to put together a circuit to automatically add water to my pool when it gets low. The sensor is a 4-20ma pressure sensor. I have a 24 VAC valve to control the flow of the incoming water. What I need is something to go in between these two pieces of equipment. It may be a couple things, I don't know. I basically need something to send 24VAC to the valve when it sees a 4 ma signal and then cut the power when it sees a 20 ma signal. I would like to plug this into a standard 110V power outlet. Can anyone help me out?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    If you give the part number of the pressure sensor and some data about the valve current, it would help.
     
  3. poolguy

    Thread Starter New Member

    May 26, 2010
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    The valve has the following voltage and current 24VAC, 370mA inrush current, 190mA holding current, 60 cycles; 475mA inrush current, 230mA holding current, 50 cycles

    As far as the pressure transducer, I will have to do a little digging if it is necessary. All I know right now is it has a 4-20ma signal.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    You might look for an alternative to that pressure sensor. The 4 - 20 ma output is used in a current loop, and is less easily worked with than one with a voltage output. The current loop output has to be received by a specialized IC and converted to a proportional voltage signal.
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
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    I have to wonder why a float setup in one of the skimmer vessels wouldnt suffice?

    A simple float on a microswitch will give you a FULL or FILL signal.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
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    This is an application that simply screams for a microcontroller interface.

    A pool needing water added occasionally is a normal circumstance. However, if there is a substantial leak in the pool, a single-minded "dumb" system that only seeks to maintain a constant water level will keep the water running even if the pool is sucked into a sinkhole.

    I would not want automatic level control without some kind of notification of water consumption; and if water consumption was out of norms, to shut down and report the malfunction.

    Without some kind of intelligence built into it, you could wind up going broke trying to pay your water bill.
     
  7. retched

    AAC Fanatic!

    Dec 5, 2009
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    ....true....

    A flow meter could be installed on the fill line and manually/visually inspected routinely to see fill water usage.

    A digital meter or even a timer that records the length of time the valve is open could accomplish the reporting to the uC.
     
  8. SgtWookie

    Expert

    Jul 17, 2007
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    I have a buddy who has a leak in his pool. I've offered to help him fix the leak several times. He keeps declining. Meanwhile, I hear his pool pump cavitating when I go over to his house, and know it's only a matter of time before he has a very expensive pump replacement - which he really can't afford at the moment.

    A swimming pool needs constant human attention.

    The best cure for a swimming pool is a bulldozer and 20 yards of dirt.
     
  9. BMorse

    Senior Member

    Sep 26, 2009
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    2 float switches will work, one for filling the pool, one to detect when the water level has gone down too far, I use a 3 float system for my septic system, 1 float tells the system when to start pumping, 1 tells the system when to stop pumping, and one that tells the system that water level is too high (Pump never came on)..... the same concept can be put to use here using 2 float switches.....


    B. Morse
     
  10. darren charles

    New Member

    May 21, 2015
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    If you've tried the above methods and are still stuck, call a plumber that specializes in Leak Detection. The one I've used does magic and since he is fast it doesn't cost that much. In fact, I now know that he would have saved me money and pain several times if I called him earlier.
     
  11. DickCappels

    Moderator

    Aug 21, 2008
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    The thread is five years old.
     
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