The document describes a water level indicator circuit that uses three probes placed at different height levels in a water tank. The circuit includes a breadboard, resistors, buzzer, LEDs, transistor, connecting wires and a 9V power supply. When the water level reaches the first probe, LED 1 turns on, and when it reaches the second probe, LED 2 turns on, and so on. When the water level passes the third probe, the buzzer sounds as an alarm to stop the water supply. This simple circuit helps prevent water wastage and reduce energy usage.

2.  Over Flow Problems
 To prevent wastage of water
 To prevent wastage of energy
 Attention and observation
 For sustainable use of water and judicious use of electricity.

3.  The Water Level Indicator employs a simple mechanism to
detect and indicate the water level in an overhead tank or any
other water container. The sensing is done by using a set of
three probes which are placed at three different levels on the
tank walls (with probe 3 to probe 1 placed in increasing order of
height, common probe (i.e. a supply carrying probe) is placed at
the base of the tank). The level 3 represents the “tank full”
condition while level 1 represents the “tank empty” condition.

6. 1. Bread-Board:
 A bread-board is a construction base for prototyping of electronics. It is used
for temporary prototyping and experimenting with circuit diagram.
2. Resistors:
 Resistor is a passive component used to control current in a circuit. Its
resistance is given by the ratio of voltage applied across its terminals to the
current passing through it.

7. 3. Buzzer:
 The buzzer produces sound. It is also used in alarm circuits.
4. LED’s:
 A LED is a two-lead semiconductor light source. It is a p-n junction diode and
emits light when activated.

8. 4. Transistor:
 In this circuit we use BC547 transistor, which is a common emitter NPN transistor. This
is basically used for amplification and switching purpose.
5. Connecting Wires:
 Few connecting wires are used for connection in the circuit.
6. Power Supply:
 A DC power supply of about 9V is taken.

9.  It is a NPN bipolar junction transistor.
 It can be used in circuits where voltages reach no more than 30V.
 It has high voltage ratings and lower noise in comparison to other transistors.
 It has a noise figure less than 10dB.
 It is basically used for switching and amplification purpose in the mentioned circuit.

12.  The operation of this project is very simple and can be understood easily. In our project “water level
indicator” there are 3 main conditions:
 There is no water or very less water available in the source tank. Intermediate level .
 There is ample amount of water available in the source tank or about to overflow.
 So let us discuss on the more about these 3 conditions
 After establishing the required connection as shown in the circuit diagram, we place the other ends of the
three wires which are connected to the base of the three transistors into a bowl at three different levels of
height.
 Suppose wire1 is at a lower height.
 Wire2 at a medium height
 Wire3 at a height from which water is supposed to overflow.
 As we start pouring water into the bowl, the water level touches the first wire (Wire1) which is at a lower
level and the circuit gets completed and current starts flowing and the first led (D1) glows.
 Gradually, as the level of water goes on increasing the other two LEDs (D2 and D3 glows) indicating that
the water has reached to maximum height.
 As the water level crosses the maximum limit, the buzzer starts beeping and thus sends an alarm so that
we can stop the supply of the water.
 Thus, this simple circuit depicts how a Simple water level indicator help us in preventing the flow of water
and further help in reducing the wastage of water and power.
 So, it turns us to be a very useful appliance which can used.

13.  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 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.