Level controller

Discussion in 'General Electronics Chat' started by sureshparanjape, Jun 11, 2013.

  1. sureshparanjape

    Thread Starter Member

    Feb 10, 2012
    I have been searching on internet for water level controller circuit. There are many but I couldn't locate what I have in mind.What I have in mind is something the figure attached herewith.
    I think if one can get the weight of the smaller pipe-column then the level of water/liquid can be ascertained continuously.Is there any problem with this idea so that something similar in concept is not available on internet?
    Thanking you
    Last edited: Jun 11, 2013
  2. JDT

    Well-Known Member

    Feb 12, 2009
    It will probably work if you have a flexible pipe from the tank to your measuring tube. A complicated way of doing this in my opinion.

    I assume you want an analog output of liquid level, not just that the level has risen or fallen to a certain point.

    The usual way to do this is using an ultrasonic sensor from the top of the tank. This actually measures the distance from the sensor to the surface of the liquid. These are commonly available or you could make your own using a pair of ultra-sonic transducers.
    sureshparanjape likes this.
  3. sureshparanjape

    Thread Starter Member

    Feb 10, 2012
    Thanks for your time and suggestion.Senior Member JDT.
    While searching for various possible ways to determine tank liquid level, I did come across the ultrasonic sensor method. It appears that the method has to surmount certain difficulties such as echo effect, moisture etc.
    There are other methods in practice.
    The arrangement of attaching vertical pipe to a water tank is a very standard fixture to avoid air bubbles, blocking in supply pipes. The idea of weighing the water of this attachment, calculating seems to be very appealing. I was certain that Google search would lead me to a circuit which does this precisely - if it could occur to me , it would have certainly occurred to somebody in the past! If it has not, there must be some difficulty in doing so! If it can become practical, it would be good for all type of liquids with known densities.
    These are ramblings of a senior(in age) person, having lot of time on hand.
    Thanks again JDT
  4. GopherT

    AAC Fanatic!

    Nov 23, 2012
    I like your idea, it is aninteresting option. Alternatively, you could put a cap on the smaller tube and add a pressure sensor to the top of the tube. The air pressure in the tube will go up as the tank fills. No flexible tubing will be needed. Also, the top of the small tube could be closed o prevent contamination.

    Another option would be to strike the side of the tank with a solenoid hammer, then use a microphone and Microcontroller to measure the frequency - pitch should go up as the tank level rises. No internal contamination, no devices inside of the tank so even flammable solvents can be sensed (calibration needed for each solvent or aqueous solution that is measured.

    The ultrasonic sensor is ok too (a more common option).
  5. panic mode

    Senior Member

    Oct 10, 2011
    pressure transducer on a tap at the bottom of a tank will give you nice reading. water is not aggressive medium.
    measuring weight of the tank is already used in many applications. the downside is sensitivity is lowered because large portion of measured value is mass of the the tank itself.