RECTIFIER

BY

PROF VISHNU NARAYAN SAXENA
RECTIFIER IS A DEVICE THAT CAN CONVERT AC IN TO DC

SO THERE ARE TWO QUESTIONS

WHY WE NEED TO CONVERT A.C.
IN TO D.C.

AND WHAT IS A.C. AND WHAT IS
D.C.
ALTERNATING CURRENT IS THAT CURRENT WHICH
DIRECTION REVERSE PERIODICALLY
AND
IN DIRECT CURRENT IS THAT CURRENT IN WHICH THE
DIRECTION OF CURRENT REMAIN SAME
CLASSIFICATION OF RECTIFIER
1. Half Wave Rectifier
2. Full Wave Rectifier
Half Wave Rectifier :-half wave
rectifier convert only
half cycle
of ac signal into d.c.
Half Wave
Rectifier
Full Wave Rectifier:- Full wave
rectifier convert full cycle of a.c.
signal into d.c.

Full Wave
Rectifier
Building Blocks of Rectifier

1.Step Down Transformer

The function of step down
transformer is to convert
high A.C. Voltage(230 V) to
Low A.C. Voltage (15V,12V
etc)Because we can't apply
high ac voltage to diode
directly
2. Semiconductor Diode
Diode is a semiconductor switching device Which has two terminal
1. Anode
2. Cathode
Diode can be conncted in any circuit either in forward bias or reverse bias
FORWARD BIAS: When anode is connected with +ve terminal of
battery and cathode is connected with –ve terminal of Battery Diode is
in forward bias and its resistance drop down to 0(r = 0) and it behaves
like a close switch
REVERSE BIAS: When anode is connected with -ve terminal of
battery and cathode is connected with +ve terminal of Battery
Diode is in reverse bias and its resistance rises up to infinite
and it behaves like an open switch
AC Voltage is first stepped down
then applied to the diode
During +ve Half Cycle Point A Will be
at positive potential whereas point B
will be at –ve Potential
Diode D Will be in Forward Bias and
behave like a close switch
And positive half cycle will be passed
as it is As Shown in fig
During Negative Half Cycle Point A
will be At Negative Potential As
Compared to Point B So Diode is in
Reverse Bias and Behaves Like an
Open Switch and negative half cycle
does not passes to the load
resistance
NOW WORKING OF RECTIFIER
DURING POSITIVE HALF CYCLE DIODE IS IN FORWARD BIAS AND
BEHAVES LIKE A CLOSED SWITCH AND POSITIVE HALF CYCLE PASSES
TO THE LOAD RESISTANCE

DURING NEGATIVE HALF CYCLE DIODE IS IN REVERSE BIAS AND
BEHAVES LIKE AN OPEN SWITCH AND NEGATIVE HALF CYCLE DOES NOT
PASSES TO THE LOAD RESISTANCE

IN THIS WAY HALF WAVE RECTIFIER CONVERT HALF CYCLE OF AN
A.C. VOLTAGE TO THE D.C. VOLTAGE
Rectifier
Rectifier
Rectifier

Rectifier

  • 1.
  • 2.
    RECTIFIER IS ADEVICE THAT CAN CONVERT AC IN TO DC SO THERE ARE TWO QUESTIONS WHY WE NEED TO CONVERT A.C. IN TO D.C. AND WHAT IS A.C. AND WHAT IS D.C.
  • 4.
    ALTERNATING CURRENT ISTHAT CURRENT WHICH DIRECTION REVERSE PERIODICALLY AND IN DIRECT CURRENT IS THAT CURRENT IN WHICH THE DIRECTION OF CURRENT REMAIN SAME
  • 5.
    CLASSIFICATION OF RECTIFIER 1.Half Wave Rectifier 2. Full Wave Rectifier Half Wave Rectifier :-half wave rectifier convert only half cycle of ac signal into d.c. Half Wave Rectifier Full Wave Rectifier:- Full wave rectifier convert full cycle of a.c. signal into d.c. Full Wave Rectifier
  • 6.
    Building Blocks ofRectifier 1.Step Down Transformer The function of step down transformer is to convert high A.C. Voltage(230 V) to Low A.C. Voltage (15V,12V etc)Because we can't apply high ac voltage to diode directly 2. Semiconductor Diode
  • 7.
    Diode is asemiconductor switching device Which has two terminal 1. Anode 2. Cathode Diode can be conncted in any circuit either in forward bias or reverse bias
  • 8.
    FORWARD BIAS: Whenanode is connected with +ve terminal of battery and cathode is connected with –ve terminal of Battery Diode is in forward bias and its resistance drop down to 0(r = 0) and it behaves like a close switch
  • 9.
    REVERSE BIAS: Whenanode is connected with -ve terminal of battery and cathode is connected with +ve terminal of Battery Diode is in reverse bias and its resistance rises up to infinite and it behaves like an open switch
  • 10.
    AC Voltage isfirst stepped down then applied to the diode During +ve Half Cycle Point A Will be at positive potential whereas point B will be at –ve Potential Diode D Will be in Forward Bias and behave like a close switch And positive half cycle will be passed as it is As Shown in fig
  • 11.
    During Negative HalfCycle Point A will be At Negative Potential As Compared to Point B So Diode is in Reverse Bias and Behaves Like an Open Switch and negative half cycle does not passes to the load resistance
  • 12.
    NOW WORKING OFRECTIFIER
  • 13.
    DURING POSITIVE HALFCYCLE DIODE IS IN FORWARD BIAS AND BEHAVES LIKE A CLOSED SWITCH AND POSITIVE HALF CYCLE PASSES TO THE LOAD RESISTANCE DURING NEGATIVE HALF CYCLE DIODE IS IN REVERSE BIAS AND BEHAVES LIKE AN OPEN SWITCH AND NEGATIVE HALF CYCLE DOES NOT PASSES TO THE LOAD RESISTANCE IN THIS WAY HALF WAVE RECTIFIER CONVERT HALF CYCLE OF AN A.C. VOLTAGE TO THE D.C. VOLTAGE