1. D IGITAL O BJECT C OUNTER Prepared & presented By Jyoti Bhaskar VII sem. EEE,VIET

2. A GENDA Introduction Circuit Diagram Circuit Working Components

3. INTRODUCTION  The statisticians use special formulae to calculate the approximate number of people coming to and going out of a place in a given time. But none of these formulae can give 100% accurate and precise results. It is impossible to manually count the same. But now using modern object counter circuit, it is possible to count the same with 100% accuracy.

4. ABOUT CIRCUIT  The circuit has one sensor fitted (at the waist-level) on the entry door. It consists of a light beam propagated on the LDR circuit. So long as the LDR is lighted, its resistance is LOW and the circuit remains silent.  But when the light beam is cut by an entering person, the resistance of the LDR increases and a single clock pulse is fed to the input of the circuit to advance the count by 1–digit

5. CIRCUIT DIAGRAM

6. COMPONENTS USED IN DC  555 configured in monostable mode (automatic dark sensor using 555)  555 configured in astable mode.  7490- decade counter  7447- BCD to seven segment display  Seven segment display- Common anode.  Resistors  Capacitors  Light Dependent Resistor (LDR)  Light Emitting Diode (LED)

7. 555 TIMER IC

8.  The 555 has three operating modes 1.) MONOSTABLE MODE 2.) ASTABLE MODE (Free running mode) 3.) BISTABLE MODE:

9. 7490 IC

10. 7447IC

11. LDR

12. SEVEN SEGMENT DISPLAY There are two types of LED 7-segment displays:- 1.) Common cathode(CC) 2.) Common anode(CA)

13. LIGHT-EMITTING DIODE (LED)

14. RESISTOR CAPACITOR PRINTED CIRCUIT BOARD

15. THANK YOU