Water Level Indicator Alarm

Problem Statement:

“To Measure the level of water in a tank to avoid water wastage.”

Abstract:

Water level indicator is widely used in many industries and houses. People generally worry
about the wastage of water, when the switch ON the motor and forget to OFF them. An Water Level
Indicator may be defined as a system by which we can get the information of any water reservoir .Water
level indicator system are quite useful to reduce the wastage of water from any reservoir, while filling
such reservoir. But for domestic purpose we cannot go for the instruments which use radar or ultrasonic
principle that costs high. Water tank overflow is a common problem which leads to the wastage of water.
In this project I am using the transistor based water level indicator circuit is very useful to indicate the
water levels in a tank. Whenever tank gets filled, we get alerts on particular levels. The LEDs is generally
used for indicate the water levels. If the water level is full, then the circuits beeps through the buzzer
notifying that the water level is full.

Introduction:

The water level indicator is defined as a system which gets the information about the water
level in reservoirs or in tanks which is used in homes. By using the water level indicator we can overcome
the overflow of water from the tankers.

The water level indicator circuit diagram monitors the level of water in the tank and
simultaneously switches on the water pump whenever the water level goes low in the water tank.When
the water level goes below the full-level probe, then the base of the second transistor Q2 opens by
switching it off.
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 and no current is flowing through collector
and emitter and LED is OFF.

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 (R1, R2, R3) at the base of each transistor, which is used to limit the
maximum Base current. Generally a transistor gets its ON state fully when a voltage of 0.7 V is applied to
the base. There are also resistors (R4, R5, R6) 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.

Note that Left most wire in the tank must be lengthier than other four wires in the tanks, because
this is the wire which is connected to positive voltage.

Operation:

This simple transistor based water level indicator circuit is very useful to indicate the water
levels in a tank. Whenever tank gets filled, we get alerts on particular levels. Here we have created 4
levels (low, medium, high and full), we can create alarms for more levels.  We have added 3 LEDs to
indicate initial three levels (A, B, C), and one Buzzer to indicate FULL level (D). When tanks gets filled
completely we get beep sound from Buzzer.

The operation of this project is very simple and can be understood easily. In our project “water
level indicator” there are 3 main conditions:

1. There is no water available in the source tank.

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.

So let us discuss on the more about these 3 conditions:

CONDITION 1: Water not available

When the tank is empty there is no conductive path between any of the 3 indicating probes and
the common probe (which is connected to 5v+ supply) so the transistor base emitter region will not have
sufficient biasing voltage hence it remains in cut off region and the output across its collector will be Vc
approximately 4.2v. As in this case the microcontroller is used in the active low region (which means it
considers 0-2 volts for HIGH and 3-5 volts for LOW) now the output of transistor which is 4.2v
approximately will be considered as LOW by the microcontroller and hence the default value given by
microcontroller to the seven segment display is 1 which indicates as the tank is empty.

CONDITION 2: Intermediate levels

Now as the water starts filling in the tank a conductive path is established between the sensing
probes and the common probe and the corresponding transistors get sufficient biasing at their base, they
starts conducting and now the outputs will be V ce (i.e. 1.2v-1.8v) approximately which is given to
microcontroller.Here the microcontroller is programmed as a priority encoder which detects the highest
priority input and displays corresponding water level in the seven segment display. In thisproject while
the water level reaches the 7th level i.e. last but one level along with display in seven segment a
discontinuous buzzer is activated which warns user that tank is going to be full soon.

CONDITION 3: Water full

When the tank becomes full, the top level probe gets the conductive path through water and the
corresponding transistor gets into conduction whose output given to microcontroller with this input
microcontroller not only displays the level in seven segment display but also activates the continuous
buzzer by which user can understand that tank is full and can switch off the motor and save water.

Circuit Components:
 4 - BC547 transistors
 6 - 220 ohm resistors
 1 - Breadboard
 3 - Colour led
 1 – Buzzer
 5 - 9v battery + battery clip

Circuit Diagram:
Water Level Indicator Project Features:

 Easy installation.
 Low maintenance.
 Compact elegant design.
 The Automatic water level controller ensures no overflows or dry running of pump there by saves
electricity and water.
 Avoid seepage of roofs and walls due to overflowing tanks.
 Fully automatic, saves man power.
 Consume very little energy, ideal for continuous operation.
 Automatic water level controller provides you the flexibility to decide for yourself the water levels for
operations of pump set.
 Shows clear indication of water levels in the overhead tank.

Types Of Water Level Indicators:

There are many different types of water level indicators including:

 Float switches
 Water level controls
 Floatless level indicators
 Single point level indicators
 Hanging water level sensors
 Conductivity level sensors
 Electronic water level indicators
 Spark plug water level indicators
 PVC water level sensors
 Wireless water level sensors
 Swimming pool water level indicators

Applications of Water Level Indicator:

 Automatic Water level Controller can be used in Hotels, Factories, Homes Apartments,
Commercial Complexes, Drainage, etc., It can be fixed for single phase motor, Single Phase
Submersibles, Three Phase motors. (For 3Æ and Single Phase Submersible Starter is
necessary) and open well, Bore well and Sump. We can control two motor and two sumps
and two overhead tanks by single unit.
  Automatic water level controller will automatically START the pump set as soon as the water
level falls below the predetermined level (usually 1/2 tank) and shall SWITCH OFF the pump
set as soon as tank is full.
 Fuel level indicator in vehicles.
 Liquid level indicator in the huge containers in the companies.

Water Level Indicator Advantages:

Water level indicator advantages include:

 Power Saver
 Money Saver
 Automatic
 Water Maximization
 Reliable Electronic Design

Water Level Indicator Disadvantages:

Water level indicator disadvantages include:

 Water level controls need to be replaced every 3 years.

CONCLUSION:

The water level Inndicator employs a simple mechanism to detect and indicate the water level in
an over head tank or any other water container. The sensing is done by using a set of four probes which
are placed at four different levels.We can conclude that this system is very beneficial in rural as well as
urban areas. It helps in the efficient utilization of available water sources. If used on a large scale, it can
provide a major contribution in the conservation of water for us and the future generations. In these days,
when the Earth's reserve of consumable water is decreasing every moment, every drop has its value.
Water level controller is a simple yet effective way to prevent wastage of water. Its simplicity in design
and low cost compo-nents make it an ideal piece of technology for the common man.

Recommendations:

In future, we want upgrade this circuit with some sensor which can automatically stop the power
supply of the driving pump or motor. As a result the future circuit is not very cheaper the the present one,
but we try our best to

 Make it simple,
 Easy to use,
 Easy to install,
 To make Available for all,
 Try to smaller than the present one.