Rectifier:-

• The process of converting AC voltage into DC voltage is known as rectification. A circuit which converts AC voltage into DC voltage is known as rectifier. Diodes are generally used for rectification. Depending on number of diodes used in the rectifier circuits the rectifiers are classified into three types. They are

1. Half wave Rectifier
2. Fullwave Rectifier
3. Bridge Rectifier

*Half wave Rectifier:-*

• The circuit diagram of Half Wave Rectifier is given below. If consists of transformer, diode and load resistor. The input and out waveforms are shown below.

Operation:-

• During the positive half cycle of the input voltage, the diode D is forward baised and it conducts the current through RL. As the resistance of the diode is negligible the total voltage is dropped across RL.
• During the negative half cycle of the input voltage, the diode D is reverse baised and hence no current flows through RL. As there is no current through the circuit so no voltage is dropped across RL.
• Thus the output across RL contains only positive half cycle and negative half cycles are eleminated. The output votage is uni directional but it is not pure DC. So the half wave rectifier gives an output which contains dc voltage and an ac voltage known as ripple.

Advantages:-

1. Simple Circuit and low cost.

Disadvantages:-

1. As Ripple factor is high powerful filtering is required to give steady dc output.
2. The power output and, therefore, rectification efficiency is quite low. This is due to the fact that power is delivered only half the time.
3. Transformer utilization factor is low.