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Full wave Rectification

BS P-III

Institute of Phsics

Full wave rectification Objects of the experiment To understand the operation of full wave Rectifier.

Introduction RECTIFIER A rectifier is a circuit that converts pulsating ac into pulsating There are three basic types of rectifier circuits: the half wave, full wave (center tapped) and rectifiers. Of them, bridge rectifier is the most commonly used.

Full wave rectification Full wave rectification is the process through which an ac sinusoidal input voltage is converted into a pulsating dc voltage with two output pulses occurring for each RL. input cycle. The full wave rectifier consists of two diodes and a load

Load

D1

Transformer 5

RL =

1K

8

D2

Fig.1 A full wave rectifier

Operation: During the positive half cycle of a.c input voltage, point 5 is positive and point 8 is negative. This makes the diode D1 forward biased and reverse biased. Therefore D1 conducts the current and D2 does not conduct the current, so current will only flow across D1 through the load resistor R L in upper half cycle as D1 shown in fig.2.

Load

Transformer 5 RL 8

1K D2

=

posetive half cycle.

Fig.2 Diode D1 conducts during posetive half cycle,while D2 acts as open switch.

During the negative half cycle, of a.c input voltage point 5 is negative and point 8 is positive. Under this condition the diode D2 is forward biased while diode D1 is reverse biased. There fore D2 conducts the current because D2 is in forward biased condition while D1 does not conduct the the D1 is in reverse biased condition. D1

Transformer

Load

5

1K

=

RL 8

D2 1

Fig.3 Diode D2 conducts during posetive half cycle,while D1 acts as open switch.

Full wave Rectification

BS P-III

EQUIPMENT ■ Oscilloscope COMPONENTS: ■ A bread board

■ 1K

resistor

■ Two diodes(IN 4007series)

■ Step down transformer (Center tapped) ■ A few connecting hard wires

PROCEDURE; 1. 2. 2. 3.

Make the Full wave circuit as shown in fig.1. Observe the rectified output on the Oscilloscope,by connecting its probe across R L . Observe the ripple on the Oscilloscope, using the feature of dc/ac coupling. Calculate the ripple factor .

OBSERVATION TABLE: S.No.

Vin (p-p)

Vp(peak voltage)

Vavg = 2Vp/

= Vp 2

Ripple factor

REVIEW QUESTIONS: 1. What is Full wave Rectification process?

2. Why can't we implement the Center tapped full wave rectifier without center-tapped transformer ?

FINAL CHECK LIST: • •

Clean your equipment/materials and workbenches before you leave. Return all equipment and materials to their proper storage area.