Under the Guidance of

Submitted by

Project Title

High Intensity Discharge lamps (HID) used for urban street light

are based on principle of gas discharge, thus the intensity is not

controllable by any voltage reduction method as the discharge path

is broken.

White Light Emitting Diode (LED) can replace the HID lamps

where intensity control is possible by pulse width modulation. The

intensity control helps in saving energy during late nights while

traffic density on the streets is low.

A programmable microcontroller is engaged to provide different

intensities at the different times of late night for energy saving for

solar based system, using a charge controller for battery charging,

overload and deep discharge protection

ABSTRACT

PROJECT BLOCK DIAGRAM

HARDWARE REQUIREMENTS

POWER SUPPLY BLOCK

STM 32 DEV. BOARD

SOLAR PANNEL

LED

PWM

MOSFET

PHOTOVOLTAIC CELLS/SOLAR CELLS

LM324

1N4007/1N4148

RESISTOR

CAPACITOR

230 V AC 50 Hz

5V DC

12V step down transformer

Filter(470µf)

5v RegulatorBridge rectifier

Please refer stm32doc provided

MOSFET(IRF 510)

The metal–oxide–semiconductor field-effect

transistor (MOSFET, MOS-FET, or MOS

FET) is a device used for amplifying or

switching electronic signals

The basic principle of the device a voltage on

the oxide-insulated gate electrode can induce a

conducting channel between the two other

contacts called source and drain

It is by far the most common transistor in

both digital and analog circuits, though the

bipolar junction transistor was at one time

much more common.

OPAMP LM324Features

Internally frequency compensated for unity gain

Large DC voltage gain 100 dB

Wideband with 1Mhz (Temperature compensated)

Wide power supply range:

Single supply 3V to 32V

or dual supplies ±1.5V to ±16V

Very low supply current drain (700 μA) essentially

independent of supply voltage

Low input biasing current 45 nA (temperature

compensated)

Low input offset voltage 2mV and offset current:5

nA

Large output voltage swing 0V to V+ − 1.5V

BC547 (NPN –Transistor)

The BC547 transistor is an NPN Epitaxial

Silicon Transistor.

It is used in general-purpose switching and

amplification BC847/BC547 series 45 V, 100

mA NPN general-purpose transistors.

The ratio of two currents (Ic/Ib) is called the DC Current Gain of

the device and is given the symbol of hfe or nowadays Beta, (β).

The current gain from the emitter to the collector

terminal, Ic/Ie, is called Alpha, (α), and is a function of the

transistor itself

1N4148

The 1N4148 is a standard small signal silicon

diode used in signal processing.

The 1N4148 is generally available in a DO-35

glass package and is very useful at high frequencies

with a reverse recovery time of no more than 4ns.

This permits rectification and detection of

radio frequency signals very effectively, as long as

their amplitude is above the forward conduction

threshold of silicon (around 0.7V) or the diode is

biased.

PHOTOVOLTAIC CELLS

Photovoltaic (PV) cells are made of special materials called

semiconductors such as silicon, which is currently the most commonly

used.

Basically, when light strikes the cell, a certain portion of it is

absorbed within the semiconductor material.

PV cells also all have one or more electric fields that act to force

electrons freed by light absorption to flow in a certain direction.

This flow of electrons is a current, and by placing metal contacts on

the top and bottom of the PV cell, we can draw that current off to use

externally.

SOLAR PANEL

Expose the cell to light, and the energy

from each photon (light particle) hitting

the silicon, will liberate an electron and a

corresponding hole.

If this happens within range of the

electric field’s influence, the electrons will

be sent to the N side and the holes to the P

one, resulting in yet further disruption of

electrical neutrality

This flow of electrons is a current; the

electrical field in the cell causes a voltage

and the product of these two is 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.

The main advantage of PWM is that power loss in the switching devices

is very low. When a switch is off there is practically no current, and when

it is on, there is almost no voltage drop across the switch.

PWM works also well with digital controls, which, because of their on/off

nature, can easily set the needed duty cycle.

The longer the switch is on compared to the off periods, the higher the

power supplied to the load is.

WORKING OF PROJECT

Solar panel being a current source is used to change battery B1 via D10. While

the battery is fully charged the voltage at cathode point of D10 goes up. This

results in the set point voltage at pin 3 of U1:A to go up above the reference

voltage because the potential divider formed out of R12, 5K variable

resistor,R13 goes up.

This results in pin no 1 of U1:A to go high to switch ‘ON’ the transistor Q1

that places drive voltage to the Mosfet IRF640 .such that the current from solar

panel is bypassed via D11 and the Mosfet drain and source

Simultaneously pin 7 of U1:B also goes high to drive a led D1 indicating

battery is being fully charged

Whenever the solar charge is low the circuit utilizes the power from battery, if

the battery goes into deep discharge ,then it utilizes power from solar power then

the Led’s flashes light

Keil an ARM Company makes C compilers, macro assemblers,

real-time kernels, debuggers, simulators, integrated

environments, evaluation boards, and emulators for

ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and 8051

MCU families.

Compilers are programs used to convert a High Level

Language to object code. Desktop compilers produce an

output object code for the underlying microprocessor, but

not for other microprocessors.

i.e the programs written in one of the HLL like ‘C’ will compile the

code to run on the system for a particular processor like x86

(underlying microprocessor in the computer).

For example compilers for Dos platform is different from the

Compilers for Unix platform  So if one wants to define a compiler

then compiler is a program that translates source code into object

code.

www.atmel.com

www.beyondlogic.org

www.wikipedia.org

www.howstuffworks.com

www.alldatasheets.com

THANKYOU