66.ppt

7/23/2019 66.ppt

1/18

LED BASED STREET LIGHT WITH AUTO MATIC

INTENSITY CONTROL USING SOLAR POWER

FROM PHOTOVOLTAIC CELLS

Under the Guidance of

Submitted by

Project Title

7/23/2019 66.ppt

2/18

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 !oltage reduction method as the discharge path

is bro"en#

$hite %ight &mitting Diode (%&D) can replace the HID lamps

'here intensity control is possible by pulse 'idth modulation# The

intensity control helps in sa!ing energy during late nights 'hile

traffic density on the streets is lo'#

programmable microcontroller is engaged to pro!ide different

intensities at the different times of late night for energy sa!ing for

solar based system using a charge controller for battery charging

o!erload and deep discharge protection

ST*+T

7/23/2019 66.ppt

3/18

P*,-&+T %,+. DIG*/

7/23/2019 66.ppt

4/18

H*D$*& *&0UI*&/&1TS

S,%* P11&%

%&D

P$/

TT&*2 345 6H

%/736

318996:31838;

*&SIST,*

+P+IT,*

7/23/2019 66.ppt

5/18

+

7/23/2019 66.ppt

6/18

The current gain from the emitter to the collector

terminal Ic:Ie is called lpha (A) and is a function of the

transistor itself

7/23/2019 66.ppt

7/18

PH,T,5,%TI+ +&%%S

Photo!oltaic (P5) cells are made of special materials called

semiconductors such as silicon 'hich is currently the most commonly

used#

asically 'hen light stri"es the cell a certain portion of it is

absorbed 'ithin the semiconductor material#

P5 cells also all ha!e one or more electric fields that act to force

electrons freed by light absorption to flo' in a certain direction#

This flo' of electrons is a current and by placing metal contacts on

the top and bottom of the P5 cell 'e can dra' that current off to use

e>ternally#

7/23/2019 66.ppt

8/18

SOLAR PANEL

&>pose the cell to light and the energy

from each photon (light particle) hitting

the silicon 'ill liberate an electron and a

corresponding hole#

If this happens 'ithin range of the

electric fieldBs influence the electrons 'ill

be sent to the 1 side and the holes to the P

one resulting in yet further disruption of

electrical neutrality

This flo' of electrons is a currentC the

electrical field in the cell causes a !oltage

and the product of these t'o is po'er

7/23/2019 66.ppt

9/18

S+H&/TI+ DIG*/

7/23/2019 66.ppt

10/18

S+H&/TI+ DIG*/

7/23/2019 66.ppt

11/18

$,*.I1G , P*,-&+T

Solar panel being a current source is used to change battery 3 !ia D39# $hile

the battery is fully charged the !oltage at cathode point of D39 goes up# Thisresults in the set point !oltage at pin 7 of U3E to go up abo!e the reference

!oltage because the potential di!ider formed out of *34

7/23/2019 66.ppt

12/18

7/23/2019 66.ppt

13/18

7/23/2019 66.ppt

14/18

7/23/2019 66.ppt

15/18

7/23/2019 66.ppt

16/18

The ;9

7/23/2019 66.ppt

17/18

QUERIE

S?

7/23/2019 66.ppt

18/18

THANKYOU