HALF WAVE RECTIFIER BY SRAVANI ANNAPURNA.A(221710303057)

HALF WAVE RECTIFIER:
The half wave rectifier consists of a step-down transformer, a diode connected to the transformer and a load resistance connected to the cathode end of the diode. The circuit diagram of half wave transformer is shown below:

This rectifier circuit consists of a resistive-load p-n junction diode and the source of AC voltage all connected in series. The rectifier circuits are operated from AC mains supply. To obtain the desired DC voltage across the load,the AC voltage is applied to a rectifier circuit using a suitable step-up or step-down transformer, mostly a step-down one, with necessary turns ratio.

The main supply voltage is given to the transformer which will increase or decrease the voltage and give to the diode. In most of the cases, we will decrease the supply voltage by using the step-down transformer. Here, the output of the step-down transformer will be in AC. This decreased AC voltage is given to the diode which is connected serial to the secondary winding of the transformer. This diode is an electronic component which will allow only the forward bias current and will not allow the reverse bias current. From the diode, we will get the pulsating DC and give to the load resistance RL.

WORKING OF HALF WAVE RECTIFIER:

The input given to the rectifier will have both positive and negative cycles. The half wave rectifier will allow only the positive half cycles and omit the negative half cycles. So first, we will see how the half wave rectifier works in the positive half cycles.

Positive Half Cycle:  In the positive half cycles when the input AC power is given to the primary winding of the step down transformer,we will get the decreased voltage at the secondary winding which is given to the diode.The diode will allow the current flowing in clockwise direction from anode to cathode in the forward bias(diode conduction will take place in forward bias)which will generate only positive half cycle of the AC.The diode will eliminate the variations in the supply and give the pulsating DC voltage to the load resistance RL. We can get the pulsating DC at the load resistance.  

Negative Half Cycle: In the negative half cycle the current will flow in the anti-clockwise direction and the diode will go in to the reverse bias.In the reverse bias the diode will not conduct so,no current in flown from anode to cathode,and we cannot get any power at the load resistance.Only small amount of reverse current is flown from the diode but this current is almost negligible.And voltage across the load resistance is also zero.