Current is used to power many electrical circuits. To convert this Alternate Current to Direct Current, a diode is used. Simply put, a diode permits current to travel in just one way. The diode’s one-of-a-kind quality allows it to function as a rectifier. In this article, we will learn more about rectifiers and their differences.
What is Rectifier?
A rectifier is a circuit that converts alternating current (AC) to direct current (DC). The converting process of electricity is known as rectification. The rectifier is constructed of semiconductor diodes to perform rectification. A diode functions as a one-way valve, allowing current to flow in just one direction.
Classification of Rectifier
The rectifiers are grouped into two types based on the kind of AC to DC conversion, i.e., half-cycle AC to DC or full-cycle AC to DC.
- Half Wave Rectifier
- Full Wave Rectifier
Half Wave Rectifier
The Half Wave Rectifier circuit is made up of a single diode and a step-down transformer, which converts high-voltage alternating current to low-voltage alternating current. Following that, a diode in the circuit will be forward-biased during the positive half of the AC cycle and reverse-biased during the negative half.
When the diode is forward biassed, it creates a short circuit; when reversing bias, it creates an open circuit. This is due to the circuit’s connecting design. The P-terminal of the diode is connected to the secondary winding of a transformer, and the N-terminal is connected to the load resistor.
As a result, the diode conducts during the positive half of the alternating current cycle. During the negative half of the alternating current cycle, it will not conduct. As a result, the voltage drop across the load resistor will occur only for the positive half of the alternating current. We shall have zero DC voltage during the negative half of the AC cycle.
Full Wave Rectifier
The Full Wave Rectifier is made up of two diodes and one center-tapped step-down transformer. The P-terminal of the diodes is linked to the transformer’s secondary winding. The N-terminals of both diodes are linked to the secondary winding’s center tapping point as well as the load terminal.
As the positive half of the alternating current cycle passes through the transformer main winding, the top of the secondary winding becomes positive while the bottom of the secondary winding becomes negative owing to mutual induction.
Diode D1’s P-terminal is linked to a positive voltage, causing the diode to function in the forward-biased zone. Due to the negative voltage at the bottom of the secondary winding, diode D2 becomes reverse-biased at the same moment.
Hence, only diode D1 conducts during the positive half cycle of AC, whereas diode D2 does not. As the negative half cycle of alternating current (AC) passes through the transformer’s main winding, the top of the secondary windings becomes negative and the bottom of the secondary windings becomes positive owing to mutual induction.
So, diode D2 is forward-biased, whereas diode D1 is reverse-biased. As a result, DC voltage will be acquired for both the positive and negative halves of the AC cycle. As a result, it is referred to as full-wave since it completes the entire AC cycle.
Difference Between Half Wave and Full Wave Rectifiers
The following table compares the key differences between half-wave and full-wave rectifiers.
|Half Wave Rectifier (HWR)
|Full Wave Rectifier (FWR)
|Converts half cycle of alternating current into direct current
|Converts the full cycle of alternating current into direct current
|Number of diodes required
|Requires only one diode
|Rectified cycles of AC
|Just half a cycle of AC (either positive or negative) is rectified
|Both positive and negative cycles of AC rectified
|Electric current through load
|The load’s electric current is not continuous
|A continuous electric current flow through the load
|Peak inverse voltage (PIV)
|The peak inverse voltage is equal to the maximum value of the input voltage, Vm
|The peak inverse voltage is equal to the double of the maximum value of input voltage, 2Vm
|The frequency of ripple output is equal to the input supply “f”
|The output frequency is double of the supply frequency, “2f”
|Transformer utilization factor
|Average output current
|Saturation of transformer core
|The DC saturation of the transformer core is a common problem
|The transformer core is not DC saturated
|Less expensive as it requires only one diode
|Costlier than a half-wave rectifier as it requires a greater number of diodes
In this article, we have discussed half-wave and full-wave rectifiers, as well as the differences between them. Since they convert AC to DC, half-wave and full-wave rectifiers are essential components in understanding electrical circuits. To obtain one-on-one home tuitions for more similar topics, choose Tutoroot’s personalized sessions.