2 Full Wave Recifier Aim: To Design and seup a full wave recifier. Componens Required: Diode(1N4001)(4),Resisor 10k,Capacior 56uF,Breadboard,Power Supplies and CRO and ransformer 230V-12V RMS. + A1 K B1 + D 4 D 1 230V rms 12V rms A2 B2 D 3 D 2 R L 10 kω Fig. 2.1: FWR wih Transformer Fig. 2.2: Transformer Elecronic Circuis Lab www.alphaku.co.in Page 1
v in 230 2 Fig. 2.3: Inpu AC Wave v in 12 2 Fig. 2.4: Transformer oupu AC Wave v V m Fig. 2.5: Diode Oupu:V M = 12 2 1.4 v V M V L Fig. 2.6: Filered Oupu: Elecronic Circuis Lab www.alphaku.co.in Page 2
Theory A Full Wave Recifier is a circui, which convers an ac volage ino a pulsaing dc volage using boh half cycles of he applied ac volage. I uses wo diodes of which one conducs during one half cycle while he oher conducs during he oher half cycle of he applied ac volage. During he posiive half cycle of he inpu volage, diode D1 and D3 becomes forward biased and D2 and D4 becomes reverse biased.hence D1 and D3 conducs and D2 and D4 remains OFF. The load curren flows hrough D1 and he volage drop across R L will be equal o he inpu volage. A ransformer is a saic elecrical device ha ransfers elecrical energy beween wo or more circuis hrough elecromagneic inducion. A varying curren in one coil of he ransformer produces a varying magneic field, which in urn induces a varying elecromoive force (emf) or volage in a second coil. Power can be ransferred beween he wo coils, wihou a meallic connecion beween he wo circuis. Faraday s law of inducion discovered in 1831 described his effec. Transformers are used o increase or decrease he alernaing volages in elecric power applicaions. Fig. 2.7: Transformer Transformer Equaions: V P V S = I S I P = N 1 N 2 = L P L S Please noe ha as we sep down he secondary curren(i S ) increases many fold. Also Z L = V S I S and Z L = V P I P = a 2 Z L Where Z L is he secondary load impedance and Z L is he apparen load impedance of he primary. Elecronic Circuis Lab www.alphaku.co.in Page 3
Diode Selecion: Power diodes can be used individually as above or conneced ogeher o produce a variey of recifier circuis such as Half-Wave, Full-Wave or as Bridge Recifiers. Each ype of recifier circui can be classed as eiher unconrolled, half-conrolled or fully conrolled where an unconrolled recifier uses only power diodes, a fully conrolled recifier uses hyrisors (SCRs) and a half conrolled recifier is a mixure of boh diodes and hyrisors.the mos commonly used individual power diode for basic elecronics applicaions is he general purpose 1N400x Series Glass Passivaed ype recifying diode wih sandard raings of coninuous forward recified curren of abou 1.0 ampere and reverse blocking volage raings from 50V for he 1N4001 up o 1000V for he 1N4007, wih he small 1N4007GP being he mos popular for general purpose mains volage recificaion. Selecion of Transformer: Selec 230V 12V,1000mA Transformer V 1 V 2 = N 1 L = 1 N 2 L 2 for 230V o 12V we ge L 1 L 2 = 2302 12 2 367 + A1 K B1 + D 4 1N4001 D 1 1N4001 230V rms 12V rms D 3 1N4001 A2 B2 D 2 1N4001 R L 10 kω Fig. 2.8: FWR wih Transformer Elecronic Circuis Lab www.alphaku.co.in Page 4
In order o implemen he ransformer in LTspice place wo inducance in he raio of 367 and orien hem such ha coupling dos are in phase.now o connec hese wo inducance use coefficien of coupling using spice direcive for k. A 1 implies ha coefficien of coupling is 100%.And we have implemened a ideal ransformer.also remember o give some small resisance in series wih inpu volage source. Fig. 2.9: Full Wave Recifier LTspice Fig. 2.10: Full Wave Recifier LTspice Elecronic Circuis Lab www.alphaku.co.in Page 5
Design of Filer Capacior and Ripple facor: v V M V L T P T Fig. 2.11: Filered Oupu The capacior discharge equaion is given by considering new ime axis. v C ( ) = V M erc For = T P we ge v C (T P ) = V M e T P RC If we make he ime consan of he circui very large compared wih ime period of waveform ie RC >> T P > T we can approximae he above equaion by and using v C (T P ) = V L ( V L = V M 1 T ) P RC = V M V L = T P RC Now seeing he figure we can see ha T P T 2 he period of waveform. V r = V M V L = V M.T p RC = V M 2fRC For design of capacior we mus consider wo more facors.the peak curren ha flows during he iniial cycle hrough he diode and capacior. i c (peak) 2π V ( M VM and i R L 2V D(peak) V ) M VM 1 + 2π r R L 2V r Elecronic Circuis Lab www.alphaku.co.in Page 6
Design of Capacior Filer: V M = 12 2 0.7 = 16.27V.Selec V r = 0.5V.Now For R=10k and f=50hz. C = V M 2 V r f R = 16.27 = 32.5µF 33µF 2 0.5 50 10k and i C(peak) i D(peak) 20mA This is way below he limi of diode 1N4001 and selec capacior raing accordingly.this maches wih simulaion resuls also. Fig. 2.12: Full Wave Recifier Wih Filer LTspice Fig. 2.13: Full Wave Recifier LTspice oupu Resul: Designed and seup a Full wave recifier wih capacior filer and obained he resul. Elecronic Circuis Lab www.alphaku.co.in Page 7
A Everycircui Simulaion You can view his experimen online using chrome browser using he following link hp://everycircui.com/circui/6155480530681856 (a) Time Response: Fig. A.1: Full Wave recifier wih Filer: Elecronic Circuis Lab www.alphaku.co.in Page 8