EEE108: Network Theory

PBL REPORT

WINTER SEMESTER 2013

DIGITAL OBJECT COUNTER

TEAM MEMBERS:

Name Reg No.

1. A.LEELA KIRAN 12BEE1020

2. A.VIJAY KOUSHAL 12BEE1024

3. Y. VENKATA SATYA ANIL 12BEE1025

Objective of the project:

The objective of our project is to build a working model of a digital object counter.

Motivation behind the project:

1) A counter machine is an abstract machine used in formal logic and theoretical computer

science to model computation.

2) In more understandable way, it is a device which calculates the number of objects fed to its

sensor and displays accordingly.

3) With the knowledge of ICs (series 74), Light Dependent Resistor (LDR) and other

electrical components we have created and build a digital object counter machine

4) The main idea on which the circuit works is the detection of absence of light by the Light

Dependent Resistor and displaying the output.

Circuit diagram:

Components used with specifications:

1) IC 7490 Decade counter.

2) IC 7447.

3) IC 555 Timer. - X 2

4) Common Anode 7 segment display.

5) Light Dependent Resistor (LDR). - X 1

6) Rheostat (Variable resistor) 100k ohm

7) Resistors:

1k ohm - X 1

330 ohm - X 9

100k ohm - X 1

47k ohm - X 1

8) Capacitors:

10 F - X 2

0.01 F - X 1

9) Light Emitting Diodes (LED) - X 2

10) 6V Battery for power supply

11) Connecting Wires

12) Bread boards - X 2

Ratings of the components used in the circuit:

COMPONENT Voltage / Current Power

1) IC 7490 Decade counter. 5.25V / 1mA 5.25mW

2) IC 7447. 5.25V / 1mA 5.25mW

3) IC 555 Timer. 16V / 200mA 3.2W

4) Common Anode 7 segment display. 3V / 100mA 300mW

5) Light Dependent Resistor (LDR). 100V / 5mA 0.5W

6) Rheostat (Variable resistor) 100k ohm 100V / 1mA 0.1W

7) Resistors:

1k ohm 150V / 666A 100mW

330 ohm 2.2V / 8.5mA 18.7mW

100k ohm 1000V / 0.1A 100W

47k ohm 200V / 1.65mA 330mW

8) Capacitors:

10 F 6.3V 3.3W

0.01 F 12V 4.8W

9) Light Emitting Diodes (LED) 3V / 300mA 900mW

Working Principle of the Project:

Digital Object Counter machine mainly has four units:-

1. Primary sensing unit - L.D.R

2. Counting unit - Decade counter IC 7490

3. Binary to 7-segment display conversion unit - IC 7447

4. Display unit - common anode seven segment display.

Advantages of the Digital Object Counter Circuit:

1. Very Low Power Consumption

2. Wide Supply Voltage Range

3. Good Noise Immunity

Drawbacks of the Digital Object Counter Circuit:

1. Loose connections while fabricating on the bread boards

2. Problem with supplying the required voltage to seven segment display

Measures to overcome the drawbacks:

1. Its better to use a PCB rather than a bread board

2. Its better to use a voltage regulator as supply rather than a dc supply battery

Applications of the project:

1. Digital Clocks

2. Digital Cameras

3. Money Counting Machines

4. Walk through metal detectors

5. X ray baggage scanners

Data Sheets of the Components:

1) IC 7490

Pin diagram:

2) IC 7477

Pin diagram:

3) IC 555 Timer

Pin diagram:

4) Seven segment display

Pin diagram:

5)100K variable resistor

Pin diagram:

6) LDR

Pin diagram:

Cost of the project:

The total amount spent for the components including breadboards is Rs 300/-

References used for the project:

1) http://www.buildcircuit.com/digital-object-counter/

2) http://en.wikipedia.org/wiki/Counter_machine

3) http://www.buildcircuit.com/ldr-engineer/

4) http://www.articlesnatch.com/Article/A-Short-History-Of-The-Currency-Counting-

Machine/8179440

Photograph of the circuit: