In these presentation we have discused about simple water level indicator circuit and its application

2. ABSTRACT
Water tank overflow is a common problem which leads
to the wastage of water. Though there are many
solutions to it like ball valves which automatically stop
the water flow once the tank gets full. But being an
electronics enthusiastic wouldn’t you like an electronic
solution for it? So here is a simple and handy DIY that
will guide you to make a circuit which will detect the
water level and will raise an alarm upon getting the
water tank full or a preset level.

3. CONTENTS
 INTRODUCTION
 COMPONENTS
 CIRCUIT DIAGRAM
 CONSTRUCTION
 WORKING
 APPLICATION
 ADVANTAGES
 DISADVANTAGES
 REFFERENCE
 CONCLUSION

4. INTRODUCTION
 This circuit is designed to determine the water level
espically in a water tank
 As the water level increases from base of the tank the
number of glowing leds increases subsequently
 Amount of water present in a tank is easily measured
 When tank is completely filled we get beep sound
from buzzer

5. COMPONENTS
 4 - BC547 transistors
 6 - 220 ohm resistors
 3 - Colour led
 1 – Buzzer
 5 - 9v battery + battery clip

6. CIRCUIT DIAGRAM

8. CIRCUIT ELEMENTS
 4-BC547 transistors
This is key element in circuit. It is used as switch.The
important property of this transistor is, this transistor
gives out put from collector only when its base voltage
is at some-ve potential than its emitter

9. RESISTOR In these circuit resistor is used to controll the
current flow to prevent damage of leds

10. LED’S
Light emmiting diodes,placed in a circuit, to show level
of water in a tank.
Generally these diodes are operate at 1.5V

11. CONSTRUCTION
 We can consider this whole circuit as 4 small circuits, each
one for indicating/alarming, when a particular level
(A,B,C,D) of water have been reached.
 When water level reaches to point A, circuit with RED LED
& transistor Q1 gets completed and RED LED glows.
 Similarly when water level reaches to point B, circuit with
YELLOW LED and transistor Q2 gets completed and
Yellow LED glows, same goes with point C.
 And finally when tank gets full (Point D), circuit with
buzzer gets completed and buzzer starts beeping.


12. WORKING
 Here we are using transistor (of NPN type) as a Switch.
 Initially there is no voltage applied to the base of the
Transistor Q1 and the transistor is in OFF state
 No current is flowing through collector and emitter
and LED is OFF

13.  When the water level reaches to Point A in the tank,
the positive side of the battery gets connected to the
base of the Transistor Q1 through the water.
 So when a positive voltage has been applied to the base
of the Transistor Q1, it gets into ON state and current
starts flowing from collector to emitter. And RED LED
glows.
 You can see resistors at the base of each transistor,
which is used to limit the maximum Base current.

14.  Generally a transistor gets its ON state fully when a voltage
of 0.7 V is applied to the base. There are also resistors with
each of the LEDs, to drop the voltage across LEDs,
otherwise LED may blow up.
 Same phenomenon happens when water level reaches to
Point B. As soon as water level reaches to Point B, a positive
voltage gets applied to the Transistor Q2,
 it gets ON and current started flowing through YELLOW
LED, and LED glows.
 With same principle, GREEN LED glow when water level
reaches to Point C.And finally Buzzer beeps when water
level reaches to D.

15. APPLICATION
 The water level indicator is used in Hotels, Home apartments,
commercial complex, and in factories.
 The pumps used in the water level indicator are single phase
motor, submersible motor, and in three phase motor.
 By using the two motors, two sumps, two overhead tanks we
cannot control by a single circuit.
 Automatically the pump will switch ON/OFF when the water
level in the tank is empty and full.
 We can also measure the fuel level in motor vehicles
 The liquid level containers are huge in the companies

16. ADVANTAGES
 The water level indicators are low cost in the market
 Any person can identify the water level easily by
hearing the beep sound
 By using this we can control the water level safely and
easily

17. DISADVANTAGES
 Leds are easily damage when currents flow and it is
sensitive to environment like hummidity temperature
 And we have to replace leds time to time

18. REFFERENCES
 https://circuitdigest.com/electronic-circuits/water-
level-indicator-alarm-circuit
 https://www.electronicshub.org/water-level-alarm-
using-555-timer/

19. CONCLUSION
 I have conclude that water level indicators is very
useful to prevent lose of water and also we can prevent
explosions in chemical plants