Rectifier:- Half wave and Full wave rectifier

Rectifier:- Rectifier is a device that is used to convert alternating potential current into direct current. It is based on the fact that resistance of depletion layer across junction decreases under forward biasing and increase under reverse biasing.

Half wave rectifier:- A primary coil in step down transformer is connected to an input alternating current source. one end of the secondary coil is connected to a P-plate of a diode and another end of the secondary coil is connected to anode plate through a load resistance RL. Here the output is obtained across load resistance.

  • During the positive half cycle of input positive alternating current source:- Let one end of primary coil P1 acquires a negative potential and another end P2 acquires of positive potential. Due to the mutual induction, one end of secondary coil S1 acquires a positive charge and another end S2 acquires a negative potential. Here P plate of diode acquires a positive potential with respect to N plate. So diode works under forward biasing, the resistance across junction diode decreases current flow in the circuit and output is obtained across load resistance (RL).
  • During the negative half cycle of input negative alternating current source:- Here one end of primary coil P1 acquires a positive potential and end P2 of primary coil acquires negative potential. Due to the mutual induction, one end of secondary coil S1 acquires a negative charge and another end S2 acquires a positive potential. Here P plate of the diode acquires a negative potential with respect to N plate. So diode works under reverse biasing, Resistance of depletion layer across junction increases, therefore, no output is obtained across RL.
  • Conclusion:- In this process, the half cycle of input alternating current source is converted into direct current. so it is known as half wave rectifier. To obtained the pure direct current output signal is filtered through a filtered circuit.

Full wave rectifier:- In full wave rectifier Primary coil in a step-down transformer is connected to input alternating current source and secondary coil are connected to P plate of both diode and N plate of both diodes are connected with each other through a load resistance (RL). The second end of the load resistance is connected to the midpoint of the secondary coil to divide the potential equally.


  • During the positive half cycle of input alternating current source:-  Let one end of primary coil P1 acquires negative potential and another end P2 acquires positive potential due to the mutual induction end S1 of secondary coil acquires positive potential and the end S2 acquires negative potential. Therefore  P plate of diode D1 comes at a positive potential with respect to N plate and P plate of diode D2 comes at a negative potential. Here diode D1 works under forward biasing, the resistance of depletion layer across junction decreases current flow through the circuit and output is obtained across load resistance. But diode D2 works under reverse biasing, so no output is obtained across load resistance (RL).
  • During the negative half cycle of input alternating current source:- Let one end of primary coil P1 acquires Positive potential and another end P2 Acquires negative potential due to the mutual induction end S1 of secondary coil Acquires negative potential and another end S2 acquires S2 acquires positive potential. Therefore P plate of diode D1 comes at a negative potential with respect to N plate and P plate of diode D2 comes at a  positive potential, here diode D1 works under reverse biasing , resistance of depletion layer across junction increases no current flow through the circuit and no output is obtained across load resistance (RL). But diode D2 works under forward biasing, So the output is obtained across load resistance (RL) and current obtained.
                                 Both half cycle of input alternating current source is converted into direct current. So it is known as a full wave rectifier. To obtained pure direct current it is filtered through a filtered circuit by using a capacitor of high capacitance.

No comments