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Wednesday, October 5, 2011

BRIDGE RECTIFER Electronic devices and circuits lab manual


BRIDGE RECTIFER

AIM: - To calculate the ripple factor of a bridge rectifier, with and without filters.

APPARATUS:-
                        Experimental board
                        Diodes, IN4007 ---- 4 Nos.
                        Resistor, 1KΩ
                        Capacitor, 100μF/25v.
                        Transformer (6-0-6v)
                        Multi meters –2 No
                        Connecting Wires

CIRCUIT DIAGRAM:-                                  
                                                                  
THEORY:-
                The bridge rectifier is also a full-wave rectifier in which four p-n diodes are connected in the form of a bridge fashion. The Bridge rectifier has high efficiency when compared to half-wave rectifier. During every half cycle of the input, only two diodes will be conducting while other two diodes are in reverse bias.

   PROCEDURE:-
1. Connections are made as per the circuit diagram.
2. Connect the ac main to the primary side of the transformer and secondary side to the bridge rectifier.
3. Measure the ac voltage at the input of the rectifier using the multi meter.
4. Measure both the ac and dc voltages at the output of the Bridge rectifier.
5. Find the theoretical value of dc voltage by using the formula,


 CALCULATIONS:-
Theoretical calculations:-
                                  Vrms = Vm/ √2
                                  Vm =Vrms√2
                                  Vdc=2Vm/П
(i)Without filter:
                             Ripple factor, r = √ ( Vrms/ Vdc )2 -1 = 0.482
(ii)With filter:                                                                 

                  Ripple factor, r = 1/ (4√3 f C RL)         where    f =50Hz
                                                                                             C =100µF
                                                                                             RL=1KΩ
   Practical Calculations:-
             Without filter:-
                                      Vac=
                                      Vdc=
                          Ripple factor, r=Vac/Vdc
               With filters:-
                                               Vac=
                                              Vdc=
                       Ripple factor,r=Vac/Vdc
 OBSEVATIONS:-
Without Filter

USING DMM
Vac(v)
Vdc(v)
r= Vac/ Vdc




With Filter

USING DMM
Vac(v)
Vdc(v)
r= Vac/ Vdc




Without Filter:-       
                       Vrms = Vm/ √2     ,   Vdc=2Vm/П ,   Vac=√( Vrms2- Vdc 2)  
        

USING CRO
Vm(v)
Vac(v)
Vdc(v)
r= Vac/ Vdc





WITHFILTER

USINGCRO
V1(V)
V2(V)
    Vdc= (V1+V2)/2
Vac=
(V1- V2)/2√3
r=
Vac/ Vdc








MODELWAVEFORM:-





PRECAUTIONS:-

1. The voltage applied should not exceed in the ratings of the diode
2. The diodes will be connected correctly

RESULT:-

The Ripple factor of Bridge rectifier is with and without filter calculated.

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