BRIDGE RECTIFIER

As we know that the full wave rectifier is divided into two according with the number of pn diodes and the transformer used. One is the center tapped rectifier and the other is bridge rectifier. In this we are going to see about the bridge rectifier.

CONSTRUCTION:
        The bridge rectifer has the four pn junction connected is a bridge manner hence it is named as the bridge rectifer. Then it consists of the transformer, resistive load and a capacitor for filtering the output wave purpose.

CIRCUIT DIAGRAM:

WORKING:
          As of the other rectifiers it has two working cycles i.e the positive and negative half cycles.

(i)DURING THE POSITIVE HALF CYCLE:
           During the positive half cycle the diodes 1 and 3 are in forward bias condition and hence the conduction takes place via the loop D1RLD3 hence output is obtained as pulsating output for positive half cycle.

(ii)DURING THE NEGATIVE HALF CYCLE:
           During the negative half cycle the diodes 2 and 4 conduct because of the forward bias condition and the diodes 1 and 3 remain in off state due to the reverse bias condition. In this case the current flows in the loop D4RLD2 hence the output is obtained as pulsating output for the negative half cycle.

INPUT AND OUTPUT WAVEFORM OF BRIDGE RECTIFIER:


Note: the upper part is the A.C input voltage and the lower is the d.c pulsating output
AVERAGE OUTPUT VALUE OR Vdc:

                  Vdc=(1/π)∫Vm sinwt dwt
                         =(Vm/π)[-coswt]lim 0-π
                   Vdc=2Vm/π
                    Idc=2Im/π

RMS OUTPUT VOLTAGE:
                     Vrms=(1/π)√[∫Vm^2 sin^2(wt) dwt]
                              =(Vm/√2√π)√[∫1-cos2wt dwt]
                              =(Vm/√2√π)√[wt-(sin2wt/2)]
                      Vrms =Vm/√2
                       Irms=Im/√2
 

RIPPLE FACTOR:
                   
                     τ=√((Vrms-Vdc)-1)
                       =√((π/2√2)^2-1)
                     τ = 0.483
EFFICIENCY:
                Effiency is given as the total power output to the total power input.
                       η=Vdc^2/Vrms^2
                         =8/π^2
                       η=81.2%
Tuf of full wave rectifier:
                    Tuf=power output /power rating of the transformer
                          =pac/Vrms.Irms
                          =8/√π^2
                   Tuf=0.8105 
MATLAB STIMULATION CIRCUIT FOR BRIDGE RECTIFIER:

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