This document describes a water level controller circuit project created by students at Gandhi Institute of Engineering and Technology. The circuit uses an IC555 timer to monitor the water level in an overhead tank and control a motor pump. It can switch the pump on when the water level falls and off when full to prevent overflow. It also includes an alarm to detect if the pump is running dry due to low voltage. The circuit provides automatic water level control and management to avoid issues like water wastage or equipment damage.

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 INTRODUCTION
 NEED FOR WATER LEVEL CONTROLLER
CIRCUIT DESCRIPTION
• POWER SUPPLY
• BI-STABLE MULTIVIBRATOR
• NOT GATE
• LED INDICATOR
• RELAY DRIVER
 WORKING PRINCIPLE
 APPLICATIONS & ADVANTAGES
 FUTURE EXPANSION
 CONCLUSION
CONTENTS:-

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 INTRODUCTION
• This simple ,economical and versatile circuit switches on the motor
pump when the water in the overhead tank falls below the lowest
level and turns it off the tank is full.
• Moreover if the pump is running dry due to low voltage,it sounds an
alarm to alert you to switch off the controller circuit to avoid coil
burn or power wastage.
• The water level controller circuit is built around IC555 to monitor
the water level in the over head tank and on /off status of the motor
through the inverters and driver circuit.

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NEED FOR WATER LEVEL CONTROLLER
• Overflow problems.
• To prevent wastage of energy.
• To prevent wastage of water.
• Attention.
• Observation.
• Automatic switch off.

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CIRCUIT FOR DESCRIPTION:
POWER SUPPLY:-
To obtain both 12V and 5V DC power supply. The circuit uses two ICs
7812(IC1) and 7805 (IC2) for obtaining the required voltages.
• In this way both 12V and 5V DC are obtained.
• Such a circuit is very useful in cases when we need two DC
voltages for the operation of a circuit.

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TO RELAY
DRIVER
10K
BC547
2
1uF
10K
BISTABLE MULTIVIBRATOR
1.5K
10K
BC547
TANK
RST SWITCH
4
LOWER
10K
10K
8
LED
1K
UPPER
VCC
NE 555
REF.
1.5K
1
6
3
0.01uF
NOT GATES
5
1uF

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• NOT GATE :-
 A NOT gate (also often called Inverter) is a logic gate. It takes one
input signal. In logic, there are
usually two states, 0 and 1. The gate therefore sends 1 as output, if
it receives 0 as input.
Alternatively it received 1 as input, and sends 0 as output.

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LED INDICATOR
A light-emitting diode (LED) is a semiconductor device that produces light from
electricity. LEDs last a long time
and do not break easily (compared to incandescent lightbulbs). They can produce
many different colors. They are efficient - most of the energy
makes light, not heat.
An LED is a type of diode that makes one color of light when electricity is sent
through it in the expected direction (electrically biased in the forwar
d direction). This effect is a kind of electroluminescence .
RELAY DRIVER
A relay is an electrically operated switch. It allows one circuit to switch a second
circuit which is completely separated from the first .

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 WORKING PRINCIPLE:-
One electrode probe is with 6V AC is placed at the bottom of tank. Next probes
are placed step by step above the bottom probe. When the water/liquid comes in
contact with the electrode tip, a conductive path is established between the sense
electrode and the tank wall/reference electrode, which in turn makes the
transistors conduct to glow LED and indicate the level of water.
The ends of probes are connected to corresponding points in the circuit as
shown in circuit diagram. Insulated Aluminum wires with end insulation removed
will do for the probe.
Arrange the probes in order on a PVC pipe according to the depth and immerse
it in the tank. AC voltage is use to prevent electrolysis at the probes.

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BUZZER DRIVER :
This section interfaces one audible piezo electric buzzer with the
controller. The controller activates the buzzer whenever there is any
fault appears in any of the channel.
PIEZO ELECRTIC BUZZER:
It is a device that converts electrical signal to an audible signal (sound
signal).It cannot drive directly to the buzzer, because It cannot give
sufficient current to drive the buzzer for that we need a driver transistor
(BC547), which will give sufficient current to the buzzer.Whenever a
signal received to the base of the transistor through a base resistance
(1.5k) is high, the transistor comes to saturation condition i.e. ON
condition thus the buzzer comes to on condition with a audible sound.
Similarly, whenever the signal is not received to the base of the
transistor, thus the transistor is in cut-off state i.e. is in OFF state thus
the buzzer does not gets activated.

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BUZZER DRIVER
1.5K
BC547
DATA
INPUT
BUZZER
VCC

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 Water level indicator is used in applications like storage
tanks, boilers etc. to indicate level of water inside.
 Easily indicate when water level is full in tank with beep
Sound.
 Low cost
APPLICATIONS & ADVANTAGES :

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FUTURE EXPANSION:
This project can be developed to achieve following advanced facility to satisfy
the Requirement of industry and society,
1. Microcontroller can be is used inside the controller PID algorithm can be
implemented.
2. Contact less sensors can be interfaced to control the level of corrosive and
highly inflammable and non-conductive type of liquids.
3. Wireless sensors can be interfaced to avoid long distance cabling.

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CONCLUSION
The equipment was tested in the field for switching a Single-phase motor
to fill the overhead tank of a house.
The operation was satisfactory and while filling the over head tank the
Liquid Level Controller takes care about the under voltage condition and
availability of water in the ground storage tank.

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