Experiment no

Object :- To study full wave and half wave ckt. with or without capacitor.

Requirement:-Model no ME 577D is used for this experiment.

S.N. Apparatus Type Range Qty. Remark1 Stepdown

transformer230v to 8 8-0-8 1 Model no.

ME 577D by maas electrons.

2 Diode 43 Filter network 14 Resistances 50

ohm,500 ohm

2(one each)

5 Toggle switch 26 Voltmeter 17 ammeter 18 Digital ac

millivoltmeter

1

9 Cro. 1

Theory:- half wave rectifier:-

In half wave rectification,the diode conducts current only during the +ive half of I/P cycle.the –ive half cycles of ac supply are suppressed i.e:-during

– ive half cycle, no current is conducted. The o/p across the load is pulsating dc these pulsating o/p are further smooth with the help of filter ckt.. efficiency is low i.e:-only 40.6%.

Full wave rectifier:-

In full wave rectifier,current flows through the load in the same direction for both half cycles of I/P ac supply.at the +ive half cycle diode d1 conducts and at the –ive half cycle diode d2 conducts through load(RL).the O/P of dc is pulsating and can be smooth with the help of filter ckt. efficiency in full wave is 81.2%.

Bridge rectifier :- The need of centre tap transformer is eliminated in the bridge rectifier.it contains 4 diodes i.e:-d1,d2,d3 and d4.

During the -ive half cycle diode d3 & d2 conduct and during –ive half cycle diode d1 & d4 conduct through load.the o/p of the rectifier is also pulsating dc can be Smoothened by the use of (pie) filter.the efficiency is more.

Ripple factor:-The ac component present in the o/p of a rectifier is called ripples.the measurement of the ac component present in o/p of a rectifier is called as ripple factor.

‘’Ripple factor = rms value of ac component/rms value of dc component’’i.e:- AC (ripple) voltage/dc voltage = 1.21

Practical diagram of half wave,full wave & bridge rectifier:-

Procedure:-

Connect the ckt as shown in the figure. Connect dc voltmeter & miliameter at the proper

place . Connect electronic ac milliameter/cro across the o/p

to measure the ripples directly. Switch on the instrument using on/off toggle

switch. Note down the reading of voltmeter & ammeter,

and ac ripples on the meter. Switch on the toggle switch s1 to connect capacitor

c1 in the ckt. and check the o/p voltage ,current & ripple.

Switch on the toggle switch s2 to connect capacitor c2, now filter become t1 type configuration.again note down the reading of voltage ,current& Ac ripples.

Repeat the experiment for different values of load resistances.

Observation:-

S.N. Reading of voltmeter

Reading of ammeter

Ripples remarks

12345

Result:-AC ripples are maximum without filter ckt. but reduces as c1 is introduced and reduce further as c2 is also introduced. Ripples are minimum when t1 type filter is used.

Precaution:- All the connections should be tight. Ammeter and voltmeter must be used in proper polarity. Reading should be taken carefully.