AIM: HALF WAVE RECTIFIER

To construct a half wave rectifier , to draw their input and output waveforms and to find the Ripple factor and regulation.

APPARATUS REQUIRED:

S.No. Name Range Quantity

1. Transformer 230 V / 6-0-(-6) 12. Diode IN4007 13. Resistor 1 kΩ 14. Capacitor 100µF 15. CRO 30 MHz 16. Bread Board 1

FORMULA USED:

Ripple Factor = Where Im is the peak current

THEORY:During positive half-cycle of the input voltage, the diode D1 is in forward bias and

conducts through the load resistor R1. Hence the current produces an output voltage acrossthe load resistor R1, which has the same shape as the +ve half cycle of the input voltage. During the negative half-cycle of the input voltage, the diode is reverse biased and there is no current through the circuit. i.e., the voltage across R1 is zero.The net result is that only the +ve half cycle of the input voltage appears across theload. The average value of the half wave rectified o/p voltage is the value measured on dcvoltmeter. For practical circuits, transformer coupling is usually provided for two reasons.1. The voltage can be stepped-up or stepped-down, as needed.2. The ac source is electrically isolated from the rectifier. Thus preventing shock hazardsin the secondary circuit.

V dc=V mπ

=DC voltageat the output

I dc=Imπ

=DC current at theoutput

I rms=Im2

=RMS value of the output current

RippleFactor=rms value of alternatingcomponent of outputAverage value of output

¿√(I rmsI dc )2

−1=√(π2 )2−1=1 . 21

Ripple factor Practical measurement:

RippleFactor=V acV dc

Regulation: The variation of dc output voltage as a function of dc load current is called regulation. The % regulation is defined as ,

% regulation=V no load−V full load

V fullload×100

PROCEDURE:1. Connect the circuit as shown in the given circuit diagram without filter capacitor.2. Measure the value of by removing the load(DRB).3. Connect the load and measure for different values of load current by varying the

resistance in DRB.4. Connect the capacitor filter and repeat the above steps 2 and 3.5. Also observe and sketch the input wave form and output wave form of the half

wave rectifier with and without filter using CRO.6. Using the formulae, calculate the values of ripple factor and voltage regulation.

MODEL GRAPHS:HALFWAVE RECTIFIER (WITH & WITHOUT FILTER):

+_

+_

Half wave rectifier without Filter

Half Wave Rectifier with Capacitor Filter

230 V 50Hz, AC

Vin

IN4001

P

N

A

VA

+

_

_

+(0-30)mA mA

(0-30)VV

1µF

DRB

Mm

To CRO

230 V 50Hz, AC

Vin

IN4001

P

N

A

VA

+

_

_

+(0-30)mA mA

(0-30)VV

+_ 1µF

DRB

Mm

To CRO

100 µFMC

MC

MC

MC

D

D

OBSERVATION:WITHOUT FILTER:

RL

(KΩ)

Idc

(mA)

Vac

(Volts)

Vdc

(Volts)

RippleFactor

=Vac/ Vdc

%Regulation

(VNL-VFL)/VFL*100

WITH FILTER:

RL

(KΩ)

Idc

(mA)

Vac

(Volts)

Vdc

(Volts)

RippleFactor

=Vac/ Vdc

%Regulation

(VNL-VFL)/VFL*100

RESULT:

Thus, the half wave rectifier was constructed and the ripple factor was calculated as Ripple factor =