electronics rectifier by irfanansari.com

Instructor: Muhammad Bilal

RECTIFIER

Monday, April 10, 2023


Half-Wave rectifier


Block diagram of a rectifier and a dc power supply with a load


Half-wave rectifier operation. The diode is considered to be ideal.


The effect of the barrier potential on the half-wave rectified output voltage is to reduce the peak value of the input by

about 0.7 V.

Thomas L. Floyd Electronic Devices, Electron Flow Version, 5e

Copyright ©2005 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458

All rights reserved.


Vp

0

-VP

2

Vi(t)

t

VD

Vp - VD

0 2

Vo(t)

t


Average value of the half-wave rectified signal





Average value of HWR

π

V

θcos2π

V

dθ0dθθsinV2π

1

dtVT

1V

P

π

0

P

2π

0 p

T

0DC


RMS Value of HWR

4

V

θsinθπ4

V

dθ2θcos12

1

π2

V dθθ

π2

V

dθ0dθθsinVπ2

1

dtVT

1V

P

π

0

P

P π

0

P

2π

0

2p

T

0

2rms

2

2

0

22

2

2

2

22

1

sin


VDC

Vrms

t0 t1 t2 t3

Vp

VO

t


The PIV occurs at the peak of each half-cycle of the input voltage when the diode is reverse-

biased. In this circuit, the PIV occurs at the peak of each negative half-cycle.





Half-wave rectifier with transformer-coupled input voltage




Instructor: Muhammad BilalThomas L. Floyd Electronic Devices, Electron Flow Version, 5e




Center-tapped Full-wave Rectifier


Full-wave rectification


Copyright ©2005 by Pearson Education, Inc.

Upper Saddle River, New Jersey 07458



Average Value

π

V2

θcosπ

V

dθθsinVπ

1

dtVT

1V

P

π

0

P

π

0 p

T

0DC


RMS Value

2

V

θsinθπ2

V

dθ2θcos12

1

π

V

dθθsinVπ

1

dtVT

1V

P

π

0

P

P

π

0

2p

T

0

2rms

2

2

0

2

2

2

22

1


A center-tapped full-wave rectifier





Instructor: Muhammad BilalThomas L. Floyd Electronic Devices, Electron Flow Version, 5e





Center-tapped full-wave rectifier with a transformer turns ratio of 1. Vp(pri) is the peak value of the primary voltage.






Center-tapped full-wave rectifier with a transformer turns ratio of 2






Diode reverse voltage (D2 shown reverse-biased and D1 shown forward-biased).






Full-Wave Bridge Rectifier

Instructor: Muhammad BilalDr. RS Monday, April 10, 2023


26

Dr. RS Monday, April 10, 2023


Bridge operation during a positive half-cycle of the primary and secondary voltages

27



Vp

0

-VP

2

Vi(t)

t

Vp - VD

0 2

Vo(t)

t

28Dr. RS Monday, April 10, 2023


Peak inverse voltages across diodes D3 and D4

in a bridge rectifier during the positive half-cycle of the secondary voltage.

Dr. RSMonday, April 10, 2023


Power supply filtering

30


Instructor: Muhammad BilalDr. RS Monday, April 10, 2023


32



Half-wave ripple voltage



The frequency of a full-wave rectified voltage is twice that of a half-wave rectified voltage



Comparison of ripple voltages for half-wave and full-wave rectified voltages with the same filter capacitor and load and derived

from the same sinusoidal input voltage.



Vr and VDC determine the ripple factor

Vp(rect) : unfiltered peak rectified voltage

Vr(pp) : peak to peak ripple voltage

VDC : average value of ripple voltage

rhwr Vr( pp )

VDC

1

2 3 fRLC

36


rfwr Vr( pp )

VDC

1

4 3 fRLC


Effects of RL and C

Monday, April 10, 2023Dr. RS

C=1000µF C=470µF

C=100µF

R=1500Ω

R=1000Ω

R=500Ω

(a) RL fixed (b) C fixed