Water Level Indicator

Discussion in 'The Projects Forum' started by Seaker, Mar 21, 2013.

  1. Seaker

    Thread Starter Member

    Feb 3, 2013
    32
    0
    I am ready for my second electrical project and it will be a simple water level indicator.
    The project calls of a 6V AC power source, my question is what would be the cheapest method of providing the 6 Volts AC?
    My AC voltage where I live is 220 volts so I suppose a step down transformer would be one solution, what about an inverter or ?

    The description and circuit for this simple device is at:

    http://www.circuitstoday.com/simple-water-level-idicator

    Thank you all for you input! :)
     
  2. edwardholmes91

    Member

    Feb 25, 2013
    183
    18
    Personally I would look for a wall plug that will give you 6VAC. You could use a DC one, but then you have to use an inventor and it probably isn't worth the money.
     
    Seaker likes this.
  3. ramancini8

    Member

    Jul 18, 2012
    442
    118
    Use a 6V wallwart, and pull it apart to remove the ac to dc parts.
     
  4. DickCappels

    Moderator

    Aug 21, 2008
    2,653
    632
    Since this project involves the AC mains and water, it is a very good idea to make sure that your circuit has a very good connection to earth. It is important because that connection might save your life.
     
  5. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    A very strange circuit. The electrodes will not be driven by AC. Because of the LEDs (and b-e junctions) will act as rectifiers, the electrodes will only see pulsating DC. Electrolytic erosion will happen. This would be OK if the circuit were for just one level, and only alarmed when the water touched the upper electrode.

    Ken

    Ken
     
    Seaker likes this.
  6. Seaker

    Thread Starter Member

    Feb 3, 2013
    32
    0
    Well there goes the prospect of doing this design for the project.

    What about this design?
    http://electroschematics.com/5764/simple-water-level-indicator-2/

    OR

    http://archive.siliconchip.com.au/cms/A_30607/article.html

    OR

    http://www.electronic-circuits-diagrams.com/alarmsimages/alarmsckt6.shtml

    I do not intend on leaving the unit continuously powered, rather than during the refill stage or to do a quick check on the level.

    Using a DC power source is much cheaper than going the AC route, still working on trying to find in insulated wires of Aluminum or stainless steel.
    I want a buzzer or alarm of some sort as well!
     
  7. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
  8. tubeguy

    Well-Known Member

    Nov 3, 2012
    1,157
    197
    KMoffet's circuit has the advantage of using a Cmos sensing device which has a much higher input impedance (higher sensitivity than the transistor inputs),

    And, it's a Schmidt trigger which would provide a more definite and stable on'off indication than the transistor sensors.
     
  9. Seaker

    Thread Starter Member

    Feb 3, 2013
    32
    0
    Hello KMoffet, thank you for the link.
    I respect your experience and knowledgeable advise that this circuit is a very good option. However as a inexperienced individual to electronics I find it difficult enough to follow schematics/diagrams.
    For me unfortunately I am at present unable to form in my mind the addition of multiple detectors as mentioned. I assume from the diagram that the area marked input probe is where one connects the level indicators to but even here I have difficulty as there is two points shown and I would have only a single wire running from the depth indicator in the tank.
    I feel that I must have at least four tank level indicators and preferably six to make this project work for me.

    Thank you all for the input it is much appreciated!
     
  10. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    Here's my concept. Not tested, but should work.

    Ken
     
    Seaker likes this.
  11. Seaker

    Thread Starter Member

    Feb 3, 2013
    32
    0
    Hello Ken;
    Thank you so much for the effort on putting this together for me!
    I will print it up and start getting the components together.

    Thanks again

    Al
     
  12. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    Need to change the schematic/circuit. I realized that the CMOS gates could not drive the LEDs at 10mA. So I added BS250 P-MOSFETs for greater current drive. If brightness was not important you could use the original circuit with 5.6KΩ resistors instead of the 1KΩ in series with the LEDs. "High brightness" LEDs are pretty bright even at 2mA.

    Sorry.

    Ken
     
Loading...