This project is a water level indicator that uses an 8-line to 3-line priority encoder (IC 74148) to encode the water level sensed by resistors into a binary number displayed on a 7-segment hexadecimal display. It can sense 7 different water levels in a tank by running a connection from ground through the tank water to inputs of the encoder. The encoder outputs the binary representation of the water level. The display then shows the level as a single hexadecimal digit. Potential applications include automatic water level controllers for homes, businesses, and vehicles to control pumps and indicate fuel levels.

1. Project Title :
Water Level Indicator
Submittedto: MissTal’at
Submittedby group members:
 Faizan Shabbir 13-ME-032
 Malik Muhammad Faizan 13-ME-061
 Muhammad Mudassar Shahbaz 13-ME-111
 Shameel Shahid Hashmi 13-ME-158
Section: A
Project
Report ADS LAB

2. INTRODUCTION :
This water level indicator consists of 8 to 3 encoder (74148- 8 line to 3 line
priority encoder) with some water indication arrangement. The encoded level is
displayed on a 7 segment digital display. This circuit uses one ‘Hex display’, it
doesn’t require driver IC to encode. It makes the implementation simple.
o Components Required:
 Power supply
 Resistors (10kΩ x8, 100Ω x3)
 IC 74148encoder
 IC 7404 NOTgate
 Hex display
 Connectingwires
 Bread board
o Introduction to apparatus:
 Encoder (IC 74148):
A priority encoder is a circuit that compressesmultiple binary inputsinto a
smaller number of outputs. The outputof a priority encoder is the binary
representation of the originalnumber starting from zero of the most
significant inputbit. They are often used to control interruptrequests by
acting on the highest priority request.
 Resistor:
Resistor is a passivetwo-terminal electrical component that
implements electrical resistance as a circuit element. Resistors act to
reducecurrentflow, and, at the same time, act to lower voltage levels
within circuits.
In electronic circuits, resistors are used to limit currentflow, to
adjustsignal levels, bias active elements, terminate transmission
lines amongother uses.

3.  HEX Display:
A HEX display is a form of electronic display device for displaying decimal
numerals that is an alternative to the morecomplex dotmatrix displays.
These displaysarewidely used in digital clocks, electronic meters, basic
calculators, and other electronic devices that display numericalinformation
CIRCUIT DIAGRAM :

4. WORKING :
Water level in the tank or any reservoir is sensed using simple pull up resistor
arrangement.
Here we define 7 levels in the reservoir. The sensed values are connected to an
encoder circuit. The encoder circuit consists of a 74148 IC, which is 8 to 3 line
encoder.
A connection from ground is dipped in water reservoir. When water level rises,
the ground comes in contact with the particular pin of encoder input.
Without the ground contact, the encoder input is Vcc through the pullup resistors.
For each and every level the encoder produces corresponding binary digits.
Next section is the ‘HEX Display’ which is a special type of 7 segment display. It is
easier to use than the regular seven-segment display because it is already
decoded. Each hexadecimal digit is displayed when its 4 bit binary equivalent is
received as input, as shown in the truth table below.
APPLICATIONS :
 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.

5.  Automatic water levelcontroller 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.