The following question will arise in any class 10th student or junior college student's mind,  What is Rectifier? An electronic device that converts alternating current (AC) into direct pulsating current (DC) is called as Rectifier. The process of converting alternating current into direct current is known as Rectification.

Types of Rectifiers:-

• Half wave Rectifier, and
• Full wave Rectifier.

Half Wave Rectifier :-

Half wave rectifier is a rectifier which converts AC voltage into a pulsating voltage using only one half cycle of the applied voltage and the process of this voltage conversion is known as Half wave rectification. Half wave rectifier circuit goes like this,

Half wave rectification :-

In half wave rectification, the rectifier conducts current only during positive half cycles of input AC supply. During negative half cycles, there is no current and hence, no voltage drop across the load.Therefore, current always flows in one direction through the load i.e. in above diagram, through R with base as L.

Equation for calculating output DC voltage is V(peak) = V(rms) * square root of 2.

Operation of Half wave rectifier :-

1. The primary of the transformer is connected to the AC power supply (in above diagram, the left hand side of two vertical lines). and then AC voltage is induced across the secondary transformer (in above diagram, the right hand side of two vertical lines).
2. During the positive half cycle of AC input voltage, diode is forward biased and conducts for all instantaneous voltage.
3. While conducting, the diode acts as short circuit so that the current flows and produces voltage across load resistor R with base as L.
4. During negative half cycle, the diode is reverse biased and hence it does not conduct any current.
5. Hence, there is no current flow or voltage drop through load resistor.
6. As a result, only positive half cycle is utilized to deliver DC power and the output voltage is same as the Input voltage. Waveforms looks something like this,

7. As the circuit uses only half cycle of AC input voltage, it is known as Half wave rectifier and process of conversion into DC power is known as Half wave rectification.