This document describes the components and circuitry of a basic traffic light controller. It includes a transformer to step down AC voltage to DC, a bridge rectifier to convert AC to DC, filters to smooth the output, a voltage regulator to maintain a constant 5V, an 8051 microcontroller to control the light sequences, LEDs to display the lights, and pushbuttons for manual control. The system aims to automatically control traffic lights based on sensor input about vehicle presence to improve efficiency while allowing manual override via buttons. It could be enhanced further with automatic shutoff when no vehicles are detected to save power.

1. Submitted To Submit By
Mrs. Meenu singh Akshay jaiswal
Rajat Jain
Shubham Sharma

2. Introduction
 A traffic light, traffic signal, or stop
light is a signaling device positioned at
a road intersection, pedestrian
crossing, or other location in order to
indicate when it is safe to drive, ride, or
walk using a universal color code.

3. BLOCK DIAGRAM
Regulator
Transformer Rectifier Filter
220v AC
5 v DC

4. CIRCUIT DIAGRAM

6. TRANSFORMER
A transformer is a
device which step-up
(or) step-down the
electrical quantities
according to the need.
It adjusts the Ac level so
that the appropriate Dc
amplitude is achieved.

7. BRIDGE RECTIFIER
 The circuit consists of four diodes
(1N4007) in which at a time only two
diodes conduct. Each diode has only
transformer secondary voltage
across it on the inverse cycle. This
circuit model allows us to have the
dc current to flow for the both
cycles of Ac input. The bridge circuit
is thus suitable for high voltage
application

8. FILTERS
 The use of Filters is to smoothen the
waveform by eliminating the ac
components from the rectifier
circuits basically capacitors are being
connected in shunt. The action of
the system occurs as the capacitor
stores energy during the conduction
period and delivers this energy to the
load during non conducting period

9. REGULATOR
 They maintain a constant voltage
level independent of load condition
or variation in the amplitude of the Ac
supply .An example of regulator is
LM78xx series It is the three terminal
device with input (1) , ground(2),
output(3) as its terminals. The voltage
required for micro controller is 5V.
Hence LM7805 voltage regulator is
used

10. MICRO-CONTROLLER UNIT
 Micro-controller works according to the
program written in it. The program is
written in such a way, so that this
controller energizes or de-energizes the
relays according to the information
received by the pushbuttons and the
sensing probe.
 The 8051 series of microcontrollers are
highly integrated single Chip
microcomputers with an 8-bit CPU,
memory, interrupt controller, timers,
Serial I/O and digital I/O on a single piece
of silicon. The 8051 is an 8-bit Machine.

11. Light Emitting Diode (LED)
 A light-emitting diode (LED) is a
semiconductor light source. The color of the
light is determined by the energy gap of the
semiconductor

12. FUTURE SCOPE
 This project can be enhanced in such away as to
control automatically the signals depending on the
traffic density on the roads using sensors like IR
detector/receiver module extended with automatic
turn off when no vehicles are running on any side of
the road which helps in power consumption saving.

13. TRAFFIC LIGHT CONTROLLE
HARDWARE KIT

14. THANK YOU