Full Wave Rectifier 

In electronics, rectifiers are the circuits which play an important role in converting Alternating current (AC) into direct current (DC). There are different types of rectifiers, but a full wave rectifier stands out as the best in terms of efficiency and precise results. A full wave rectifier utilises positive as well as negative halves of the waveform which is the reason for its successful output. Knowing how a full wave rectifier operates and its benefits is essential to get stable and high-performance power conversion, regardless of whether you're powering a simple gadget or a complex system.

1.0Full Wave Rectifier Principle

The ability of diodes to allow the current to flow through them in just a single direction is the foundation of the Full Wave Rectifier Principle. Using this characteristic, a full-wave rectifier transforms an AC waveform's positive and negative cycles into a unidirectional current. This can be achieved by arranging diodes to alternately conduct the positive and negative AC input. In other words, a full wave rectifier follows a principle which ensures that the current always follows a single direction. 

2.0Full Wave Rectifier Working

The full wave rectifier operation can be understood by analysing its working during both the positive and negative cycles of the AC waveform. The full wave rectifier is divided into two common configurations that are: 

Center-Tapped Full Wave Rectifier

• Positive Half Cycle: One of the two diodes conducts the current when the AC input is positive, which allows the current to flow via the load resistor in the forward direction. 
• Negative Half-Cycle: The other diode conducts during the negative half-cycle, but the output remains consistent because the current continues to flow through the load resistor in the same direction.

Bridge Rectifier (Diode Bridge Full Wave Rectifier)

Four diodes are included in this arrangement, which is a bridge. Two of the diodes conduct during the positive half-cycle, allowing current to flow through the load resistor in a single direction, and the other two conduct during the negative half-cycle, ensuring that the current flows through the load in the same direction.

3.0Full Wave Rectifier Waveform

Positive pulses occur twice each cycle of the AC input, once during each half-cycle, making up the pulsating DC signal that a full wave rectifier produces. As both the positive and negative halves of the input waveform are used, this waveform is smoother than the output of a half-wave rectifier. In the Full Wave Rectifier Graph or waveform, the AC input waveform is plotted on the x-axis; on the other hand, the output voltage is plotted on the y-axis.

4.0Formula Related To Full Wave Rectifier

Several formulas are associated with a full wave rectifier which is important for understanding as well as solving the problems related to performance and characteristics. These formulas are: 

Peak Inverse Voltage (PIV): It is the maximum reverse voltage which a diode experiences during the rectification of AC, which is equal to the peak value of the AC input voltage (V_Peak). Mathematically, it can be written as: 

$PIV=V_{Peak}$

DC Output Voltage (V_DC): The DC output Voltage is the average output voltage of the rectifier, which can be calculated with the help of the following formula: 

$V_{DC}=\frac{2V_{max}}{\pi }$

Here, V_max is the peak voltage of the AC input. 

RMS Value of Current (I_RMS): The RMS or Root Mean Square value of the current is commonly used to calculate the effective current of the circuit. In a full wave rectifier, the RMS value of the output current can be calculated using this formula: 

$I_{RMS}=\frac{I_{max}}{\sqrt{2}}$

Rectification Efficiency (η): As the name suggests, rectification efficiency is the indicator of the efficiency of the rectifier, which converts AC power into DC power. The formula to find the Rectification Efficiency is as follows:  

$\eta =\frac{P_{DC}}{P_{AC}}$

Here, 

P_DC = DC power delivered to the load

P_AC = AC power supplied by the source

Form Factor (FF): The output voltage's RMS value divided by its average output voltage is known as the form factor. It indicates the waveform's form, including whether it has ripples or is more similar to a clean DC.

$FF=\frac{V_{RMS}}{V_{DC}}=\frac{\sqrt{2}}{2}\approx 1.11$

Peak Factor (PF): It is the ratio of the peak values of the output voltage to the RMS value of the output voltage. The peak factor of a full wave rectifier can be expressed as: 

$PF=\frac{V_{Peak}}{V_{RMS}}=\sqrt{2}$

5.0Difference Between Full Wave Rectifier and Half Wave Rectifier

Full Wave Rectifier	Half Wave Rectifier
It rectifies both the positive and negative halves of the AC.	It can rectify only one-half of the AC, which can either be positive or negative.
The number of diodes can vary from two to four.	It uses only one diode.
The output of a full wave rectifier is the type of pulsating DC with both halves of AC being used.	It gives only half the AC cycle of pulsating DC.
As both the AC cycles contribute to the output in a full wave rectifier, the average remains higher.	The average output voltage is lower than that of a full wave rectifier due to the presence of only half the AC cycle.
These rectifiers are used for high-power and voltage appliances where a more smooth DC is needed.	It is used for low-power applications and simple circuits.
Circuit diagram for full wave rectifier	Circuit diagram of half wave rectifier