This document describes a simple water level indicator circuit using LEDs and transistors. The circuit uses 5 probes placed at different levels in a water tank to sense the water level. When the water touches the minimum level probe, an LED lights up to indicate a low water level. Additional LEDs light up when the water reaches medium and maximum levels. The circuit costs about 322 taka to build and can help conserve water and energy by detecting overflow and automatically shutting off water flow.

1.  GROUP MEMBERS
 Tanmoy Das (13-23395-1)
 ARIF ABUL AHSAN (13-23350-1)
 ALAM, S. M. NUR (13-23467-1)
 SubmittedTO======>

4.  Overflow Problems
 To PreventWastage Of Energy
 To PreventWastageOfWater
 Attention
 Observation
 Automatic Switch Off

5.  1.Bredboard (1 Pcs)
 2.Bjt ---BC547 NPN ( 4 Pcs)
 3.LED of different color (3 Pcs)
 4.Resistence—220 ohm (6 Pcs)
 5.Buzzer (1 Pcs)
 6. Battery (9V) (1 Pcs)
 7. ConnectingWire
 8.A Bowl
 9.Water

8.  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 9V battery and it
consumes only very less current.

9.  The circuit consisting of 5 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,D, and
E 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
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 ProbeA, a
bare copper wire can be used.

10.  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 transistorT1
via a 220Ω 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

13.  Breadboard==250Tk =============220
 Led =====2TK(per piece)====2*3===6
 Bjt=====4TK(per piece)====4*4====16
 Battery (9V)====================40
 Resistance=====================10
 Buzzer========================20
 ConnectingWire================10
Total============322

14.  Water level indicator is used in applications like
storage,tanks,boilers e.t.c. to indicate level of
water inside.
 Easily indicate when water level is full in tank
with beep Sound
 It can be used to measure any liquid which are
electricity sensative
 No extra sensor need.Copper wire can be used
as sensor.
 To save energy
 To save water
 Low Cost

15.  Digital Fundamentals-Thomas L.Floyd(8th
Edition)
 www.electronicsforyou.com
 https://www.youtube.com/watch?v=uQj8GK
QgQxg
 www.mycircuits9.com