Simple Water Level Indicator




Here’s a SIMPLE WATER LEVEL INDICATOR CIRCUIT. It is best suited for overhead water tanks to display the amount of water. The circuit consisting of 3 LED’s used to indicate minimum, medium and maximum levels. It is possible to increase the count of indicator LED’s and make it more convenient. The circuit is powered by a 6V battery and it consumes only very less current.


COMPONENTS USED

COMPONENTS
RATING
QUANTITY
Transistors
BC548C
3
Led Bulbs

3
Sensing Probes
18 SWG COPPER WIRES
4
Resistors
220KΩ
3

220Ω
3
Battery
6V
1


CIRCUIT DIAGRAM

simple water level detector




The circuit consisting of 4 sensing probes which is dipped in water to sense the level of water. The probe A is connected as common to other three, which should be at the bottom most part of the water tank, also it act as a reference level. The probes B, C, and D are set as minimum, middle and maximum level respectively. Assemble the circuit on a general purpose PCB and enclose it in a casing and mount it inside your home with the indicator LED’s pointing out of the box. A short length three, 18 SWG copper wires can be used as sensing probes and for common sensor Probe A, a bare copper wire can be used.

When water in the tank touches the probe A and B both, a small current flows from A to B through water and to the base of transistor T1 via a 220KΩ resistor. As a result the transistor conducts causing the LED1 to glow. Similarly, when water touches sensor C, LED2 glow and indicates that the tank is half-filled. Finally, when the water touches sensor D, LED3 glows and indicates the tank is completely filled. You can also combine a WATER TANK OVERFLOW ALARM CIRCUIT with it.



Kindly Bookmark and Share it:



21 comments:

  1. Hi Sir,
    1) Is there any special purpose behind using transistors as switch whereas we can just use electrodes as switch?
    2) Does using transistor rather then only electrodes for switching affects the power consumption of circuit?

    ReplyDelete
  2. The Circuit doesn't works without using Transistors.

    ReplyDelete
  3. Can we use any other resistor other than 220k ohm and 220 ohm?

    ReplyDelete
    Replies
    1. You can use two 100 ohms or 100k ohms resistors in series instead of 220 ohms/Kohms.

      Delete
  4. why the 220 ohm resistor gets heated when the circuit is on?
    where to connect the negative terminal of battery?

    ReplyDelete
  5. hey put the relay in last last led to cantrol auto tank

    ReplyDelete
  6. Exactly........... You said it right man :)

    ReplyDelete
  7. why do we need resistors and transistors....the circuit can be completed without them also...

    ReplyDelete
    Replies
    1. It doesn't works without Resistors and Transistors. Because pure water has lower conductivity and this makes the circuit Incomplete.

      Delete
  8. i tried and unable to make 3rd transistor work can u please suggest what to do in this site or else to my mail smilesboquet@gmail.com plz reply............. early........

    ReplyDelete
  9. can the led are changed to relay to turn on or off an AC water pump?

    ReplyDelete
  10. Would this work with a BC548B?

    ReplyDelete
    Replies
    1. It only worked after removing the 220ohm, any idea why?

      Delete
  11. With either the BC548b or BC548C the circuit did not work when I have the 220ohm resistor going to power. The circuit only works when I have the anode of the LED to power and the resistor in between the LED and the collector of the transistor. Any ideas?

    ReplyDelete
  12. is it works in 2n2646 or bfw10 transistor

    ReplyDelete
  13. Thanks for the circuit.
    Can I expand this circuit to show more than 3 levels?
    Suppose i want to show 10 levels, can i add 7 more transistors/resistors/LEDs in the same fashion?

    ReplyDelete
    Replies
    1. Yes, you can expand the circuit in the same way for more levels...

      Delete