1. HIGHWAY LIGHTING SYSTEM WITH AUTO TURN OFF ON DAY TIME
SUBMITTED BY
EDGEFX TEAM

2. ABSTRACT
High Intensity Discharge lamps (HID) used for urban street light are based on principle of gas discharge
White Light Emitting Diode (LED) can replace the HID lamps where intensity control is possible by pulse width modulation

3. BLOCK DIAGRAM

4. HARD WARE EQUIPMENTS POWER SUPPLY BLOCK
MICROCONTROLLER (AT89S52/AT89C51)
LED
PWM
LDR(LIGHT DEPENDENT RESISTOR)
MOSFET
BC547
1N4007
RESISTORS & CAPACITORS

6. EMBEDDED SYSTEMS Definition for :- EMBEDDED SYSTEMS
A combination of hardware and software which together
form a component of a larger machine.
An example of an embedded system is a microprocessor that
controls an automobile engine.
An embedded system is designed to run on its own without
human intervention, and may be required to respond to
events in real time.

7. EMBEDDED SYSTEMS

8. AT89S52 MICRO CONTROLLER Compatible with MCS®-51 Products
8K Bytes of In-System Programmable (ISP) Flash Memory
4.0V to 5.5V Operating Range
Crystal Frequency MHZ
Three-level Program Memory Lock
256 x 8-bit Internal RAM
32 Programmable I/O Lines
Three 16-bit Timer/Counters
Eight Interrupt Sources
Full Duplex UART Serial Channel
Watchdog Timer
AT89S52

9. PIN DIAGRAM OF AT89S52

10. LDR(Light Dependent Resistor)
A photoresistor or light dependent resistor (LDR) is a
resistor whose resistance decreases with increasing incident
light intensity. It can also be referred to as photoconductor.
If light falling on the device, the photons absorbed by the
semiconductor give bound electrons enough energy to jump
into the conduction band.
The resulting free electron (and its hole partner) conduct
electricity, thereby lowering resistance.

11. A photoelectric device can be either intrinsic or extrinsic
A photoelectric device can be either intrinsic or extrinsic. An intrinsic semiconductor has its own charge carriers and is not an efficient semiconductor, e.g. silicon.
Extrinsic devices have impurities, also called dopants, added whose ground state energy is closer to the conduction band; since the electrons do not have as far to jump, lower energy photons (i.e., longer wavelengths and lower frequencies) are sufficient to trigger the device.
Example of extrinsic devices is phosphorous atoms

12. PWM
The PWM switching frequency has to be much faster than what would affect the load, which is to say the device that uses the power.
The term duty cycle describes the proportion of on time to the regular interval or period of time;
a low duty cycle corresponds to low power, because the power is off for most of the time. Duty cycle is expressed in percent, 100% being fully on.

13. PWM APPLICATIONS Telecommunications Power delivery Voltage regulation
Audio effects and amplification.

14. MOSFET
Metal–Oxide–Semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET)
MOSFET is a device used for amplifying or switching electronic Signals

15. MOSFET as a switch & P- Type , N-Type MOSFET

16. BC547 The BC547 transistor is an NPN Epitaxial Silicon Transistor.
The BC547 transistor is a general-purpose transistor in small plastic packages.
It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.
Whenever base is high, then current starts flowing through base and emitter and after that only current will pass from collector to emitter

17. BIBILOGRAPHY
The Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education.
ATMEL 89S52 Data Sheets.

18. THANK ‘Q’