a full wave rectifier

7/21/2019 A Full Wave Rectifier

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PHYSICS

PROJECT REPORT ON

Full Wave Rectifier

SUBMITTED TO: MR. VINOD CHAUHAN

SUBMITTED BY: PAWAN KUMAR XII-B

D.A.V. PUBLIC SCHOOL VASANT KUNJ

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Index

1).Aim

2).Introd !tion

").T#$or% In&o'&$d

(). *t$ri*'+ r$, ir$d in !on+tr !tion

-).D$t*i'+ o m*t$ri*' +$d

/).Cir! it Di*0r*m

).Conn$!tion D$t*i'+

).3or4in0

5).R$!ti i$d D.C. Vo't*0$

16).O7+$r&*tion11).R$+ 't

12).Bi7'io0r*8#%

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A FULL WAVE RECTIFIERAim : To construct a full wave recti er and show that theAlternating Components are recti ed into a direct current.

Introduction : A full wave recti er is a device which is used torectify all the alternating current components in analternating supply and ma e it purely a direct current.

The two alternating halves of an alternation current arerecti ed in a full wave recti er which is an advantage

over a half wave recti er. !ost electronic devices cannotwithstand very high voltage or alternating current due toits intense high power. The use of "atteries in all devicesis not practical as their replacement and dura"ility is ahuge pro"lem as the device has to "e dismantled eachtime for such a replacement. #o these recti ers are usedin most of the electronic devices li e T$%s& 'adios&Chargers& and (ights etc. There are several stages in a

recti er. )ased on their recti cation they are classi edinto two. The single staged * multi staged. +n the multistaged recti ers& more than two diodes are used andthese are used in the a"ove,mentioned devices. Thesingled staged recti er has only 2 diodes& the one we areto discuss in this pro-ect. The multi diode recti er hasonly 2 diodes& the one we are to discuss in this pro-ect.

The multi diode recti ers has an e ciency / 0 . 3 while

that of the single is only 41.23Theory involved The input transformer steps down the A.C mains from256$ 7nominal8 to $ "etween the center tap and either of the two ends of the secondary winding. The transformer

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has a capa"ility of delivering a current of 966 mA. The $ A.C. appearing across the secondary is the '!# value of the waveform and pea value would "e

1. 1 ;4. volts.

The diodes rectify the A.C waveform appearing across thesecondary with the help of alternate forward and reverse"iasing. The capacitor further lters 003 of the residentcomponents and this is left to pass through the resistanceand emerges out as <ve and =ve. The "ul" connectedveri es the output as it wor s on >irect Current and ifused on an Alternating Current& the ?uctuation will "urnout the "ul".

Materials required in the construction: Connecting wires& a plug& single lead wire , 2m& 5 =nuts * )olts of 2 to 5cm length& circuit "oard of mica& asmall "o to place the model& a transformer& a capacitor&A 'esistor 71@ 8& P,B -unction diodes& +nsulation tape&)lades& soldering wa & soldering lead& soldering iron *sand paper.

etails o! the materials used :i8 Connecting wires and a plug A normal insulatedcopper wire are a"le to withstand 256 = 296 v is reDuired.ii8 #ingle lead wire Thin wire with one single strand ofcopper well +nsulated and a"le to conduct a current of 1ampere or a >.C. current e ciently.iii8 A circuit "oard A normal "oard of mica facilitated

with clips to simplify the connection.iv8 Buts and "olt +n order to the "oard * transformerrmly. #iEe 2 = 5 cm.

v8 #oldering wa * lead The wires are to "e solderedrmly to ma e the connection tight so for this a thin lead

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wire is reDuired to a the connections and wa to ma ethe lead to hold on when soldered.vi8 A small "o To place the eDuipment safely.vii8 A "ul" To test the output voltage whether >irector not.#peci cation 2.2 = v it will get "urnt onapplication of A.C.viii8 A ,6, transformer Transformer +t is a device usedto change the voltage of an alternating current. Thetransformer which converts low voltage to high voltage iscalled a step up transformer whereas the one whichconverts high voltage to

low voltage is called a step down transformer. +t consistsof alaminated core consisting of two coils& a primary * asecondary coil. +n a step up the num"er of turns in thesecondary is greater than that of the primary and thereverse in a step down transformer. Fere we use a stepdown transformer which steps down 256$ to $ "etweenthe secondary terminals and the center tap.

i 8 A Capacitor The a"ility of a metal to store electriccharges measures the capacitances of a conductor. +tprovides high impedance to Alternating Current andstores them while all the >.C components are left to pass.

There are diGerent types of capacitors =a8 PA'A((H( P(ATH CAPAC+TI'"8 #PFH'+CA( CAPAC+TI'c8 CJ(+B>'+C(A( CAPAC+TI'

Fere we deal with a Cylindrical Capacitor.+t consistsof twocoa ialconducting cylindrical shells. >ue to attraction"etween unli e charges& the charges spread out uniformlyand thus it gets charged. Capacitance is measured in itK Larads. The reactance a capacitors oGers to A.C.Current ; 1 c MN where N is the freDuency of the supply. +t

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does not dissipate any power * the energy stored in iteDual to O C$ 2. +n a capacitor $oltage does not changeinstantaneously. +t leads current *voltage "y an anglediGerent of 06 6 .

The capacitor can "e connected in 2 ways18 +n #eries ;1MC;1MC 1<1MC2< *28 +n Parallel ;7C ; C1 < C2 < C5 8 Fere we usecapacitor of 1666 K L * 29 v.

8 A 'esistor A resistor is an electronic componentswhose resistance value tells us a"out the opposition itoGers to the ?ow of electric current. 'esistance ismeasured in ohms 7 8.Qe determine the value of a

resistor using the color coding on the rings of the resistor=1. )lac = 6 . Rreen, 92. )rown = 1 S. )lue,5. 'ed = 2 4. $oilet,S

. Irange = 5 0. Rrey,49. Jellow = 16. Qhite,16

Tolerance

Rold , 93#ilver , 163Colorless , 263!easurement1 st Color , 1 st digit

2 nd Color , 2 nd digit

5 rd Color , Power to 16th Color , Tolerance

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Lor H.g.: Lor a resistor of color code = "rown& "lac & green* gold.

The resistance value is 16U16 9 93.Fere we use a singleresistor of )rown& 'ed& 'ed * Rold color rings.

+t%s $alue ; 12U16 2 93.

'esistance can "e connected in 2 ways =

+n series& ' ; 7'1 < '2 < '5 ..8 *

+n Parallel

1M';1M' 1<1M' 2<

i8 P,B -unction >iodes Qhen one side of asemiconductor crystal 7Rermanium or silicon8 is dopedwith acceptor impurity atoms and the other side with

donor impurity atoms a PB -unction is formed. +t is also called a semiconductor orcrystal diode. Qhen diGusion of the two regionsoccur a resultant potential "arrier is created "etween thetwo sides due to migration of electrons and holes.

Qhen the diode is connected with P side to positiveterminal of a "attery* B side to =ve terminal it is said to"e forward "iased * reverse "iased when reversed. +nforward "iasing the applied positive potential repels theholes and turns a current is made to ?ow overcoming theinternal potential )arrier. Qhile in reverse "iasing the =veelectrons

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1 st attract the holes and widen the )arrier and then onlythe repulsion "etween the inner electrons occur andcurrent ?ows. #o theoretically no current ?ows throughdue to the widening of the Potential "arrier "ut practicallya very small current does ?ows through. >iGerent typesof diodes are present =1. Vener diode2. PB -unction diode5. (H>

. (A>9. #olar cellFere we use a P,B -unction diode. The grayish ring

indicated the B side and the )lac color P side.ii8 Linally& small eDuipment such as a soldering iron to

solder the lead& )lades& holders& insulation tapes = toinsulate the wire from shoc ing and sand paper = to ru"the o idiEed wire ends are used. C+'CW+T >+AR'A!

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Connection detailsConnections are done as in the circuit. The A.C. supply isgiven to "oth the input wires of the transformer and thetwo ends of the secondary coil is given to the P side ofthe two diodes and the B side of the diodes are twinedand then connected to one end of the capacitor and theother end to the center tap lead and to the resistor.Lurther& the other end of capacitor with the diode connection isconnected to the other end of the resistor. Connect2 leads on "oth the ends of the resistor to measure theoutput and this is connected to the <ve * ,ve terminals of the "ul".

Wor"in#

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1 st when the A.C. is supplied to the transformer& it stepsdown the256$ main supply to volts. +t has a capa"ilityof delivering a current of 966mA. The volts A.C.appearing across the secondary is the '!# value and thepea value is 4. volts. >uring the 1 st half cycle of theA.C. input >iode >1 is forward "iased and a current X+%?ows in the circuit in the direction S1D1ABEOS1 . >uringthis time diode >2 is reverse "iased. #o it does notconduct any electric current. >uring the ne t half cyclethe diode >2 is forward and >1 is reversed. Fence >2conducts current in the direction S2D2ABEOS2 and >1does not conduct any current. +n su"seDuent half cycles

of the A.C current the a"ove processes are repeated. +n"oth the half cycles it is clear that current ?ows throughthe resistor in only one direction A)H. Hven though thevoltage across '( is unidirectional it will still contain a fewA.C components. This is ltered and made smooth using acapacitor& which lters 003 of the A.C current. A resistoris then used to ad-ust the output voltage. Qe can thentest the oMp $oltage using a multi,meter.

H ciency of 'ecti cation ,Y ; >.C power output Total A.C input power for a halfwave recti er&Y / 6. 6 ; 6. 3 for a full wave recti er& the one usedhere is Y / 6.412 ; 41.2 3)y the use of more num"er of diodes the e ciency can"e increased to a ma imum of 0 . 3. Fere we only use 2diodes. The use of multiple capacitors also nearly lters

all A.C components from the supply and resistance isad-usted for the reDuired output. As this is a simplecircuit& only one capacitor and a resistance is "eing used.)ut there will "e slight factor of A.C. current still left in theoutput "ut it is negligi"le.

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'HCT+L+H> >C $I(TARH

I)#H'$AT+IB:Capacitance 7C8 7KL8'esistance 7'8 7@ 8

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Iutput $oltage 7>C8.

CAPAC+TI' 7KL8 'H#+#TABCH7@ 8 IWTPWT$I(TARH7>C8

1666 946 19.651666 290. 15.911666 1. 1 . 01666 9 5. 1 . 4

'esult: A full Qave recti er is constructed * output voltagefor diGerent output resistance is measured and ta"ulated.

)+)+(+IR'APFJ18 Hlectronic pro-ects for "eginners "y A.@ !anini28 Comprehensive physics 7class Z++ & BCH'T "ased858 Comprehensive practical physics

8 BCH'T "ased C)#H te t for Z++98 Qe"site: www.yahoo.com

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a full wave rectifier

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