Full Wave Rectification Using 2 Diodes

Full wave rectification is used to convert alternating current (AC) into direct current (DC). 

Half Wave Rectification

In half-wave rectification, only one-half of the AC waveform is used to create a DC signal. This is done by using one diode, which only allows current to flow in one direction only.

When the AC signal is positive, the diode conducts and the current flows through it. But when the AC signal is negative, the diode becomes reverse-biased, and the current does not flow. Half Wave Rectification is covered in detail here.

Full Wave Rectification Using two diodes

It uses two diodes instead of one, which allows both halves of the AC waveform to be used. This results in a more efficient conversion from AC to DC. 

Basic Principle

The basic principle behind full-wave rectification without capacitance is to use a center-tapped transformer. A center-tapped transformer has a middle tap on the secondary winding, which divides the secondary winding into two equal halves. 

Steps Involved

1. An AC signal is applied to the primary winding of the center-tapped transformer.

2. When the AC signal is positive, the diode connected to the upper half of the secondary winding conducts, allowing the current to flow in one direction.

3. Meanwhile, the diode connected to the lower half of the secondary winding becomes reverse-biased and does not allow current. 

4. When the AC signal becomes negative, Diode change their roles. The diode connected to the lower half conducts now and allows the current to flow in the opposite direction, while the diode connected to the upper half blocks the current.

5. Thus by switching between these two diodes, both halves of the AC waveform are passed through and a DC is obtained. 

                    Images from Multisim

Advantages of Full Wave Rectification

It doubles the frequency of the output in comparison to half-wave rectification. However, without the use of a capacitor, the resulting DC output may not be as smooth and may have some fluctuations or ripples.