In a large number of electrical and electronic circuits, DC voltage is required for its operation. We can simply alter the AC voltage into DC voltage by using a device called the PN junction diode. One of the most significant applications of a PN junction diode is the rectification of AC into DC. A PN junction diode permits electric current in only one direction i.e, forward bias condition and blocks electric current in reverse bias condition. This single property of the diode lets it edit like a rectifier. This article discusses different types of rectifiers and their comparisons.
A rectifier is an electrical device that passes an Alternating Current (AC) into a Direct Current (DC) by using one or more P-N junction diodes.
What is a rectifier?
A Rectifier is an electrical device that is made of one or more than one diodes that converts the alternating current (AC) into direct current (DC). It’s used for rectification where the process below shows that how it converts AC into DC…
What is Rectification?
Rectification is the process of conversion of the alternating current (which periodically changes direction) into direct current (flow in a single direction).
Types Of Rectifiers:
There are mainly two types of rectifiers:
A rectifier is an electrical device construct of one or more diodes that allow the flow of current only in one direction. It basically converts alternating current into direct current. Rectifiers can be cast in several shapes as per necessity like semiconductor diodes, silicon controlled rectifiers, vacuum tube diodes, mercury-arc valves, etc. In our former articles, we have explained diodes, types of diodes in detail. But in this, we are going to give trifles of rectifiers, types of rectifiers and its applications, etc.
As the name suggests, the half-wave rectifier is a type of rectifier that converts half of the AC input signal (positive half cycle) into pulsating DC output signal and the remaining half signal (negative half cycle) is blocked up or lost. In the half-wave rectifier circuit, we use only a single diode.
During the positive half of the AC input, the diode becomes forward biased and currents start flowing through it. During the negative half of the AC input, the diode becomes reverse biased and current stops flowing through it. Output waveform across the load is shown in the figure. Because of high wave content in the output, this type of rectifier is seldom used with pure resistive load.
- Positive Half Wave Rectifier:
A half-wave rectifier that converts only the positive half cycle and blocks the negative half cycle.
- Negative Half Wave Rectifier:
A negative half-wave rectifier converts only the negative half cycle of the AC into DC.
All types of rectifiers, a half-wave rectifier is the simplest of them all as it is created of only a single diode.
Full Wave Rectifier:
A full-wave rectifier passes both positive and negative half cycles of the AC (alternating current) into DC (direct current). It provides double output voltage compared to the halfwave rectifier
A full-wave rectifier is built up of more than one diode.
There are two types of full-wave rectifiers.
A bridge rectifier uses 4 diodes to pass both half cycles of the input AC into DC output.
Using the same secondary voltage, this bridge rectifier can produce almost doubled as the output voltage as compared with a full-wave center-tapped transformer rectifier. During the positive half of the input AC diodes, D1 and D2 are forward biased and D3 and D4 are reverse biased. Thus load current flows through D1 and D2 diodes. During the negative half cycle of the input diodes, D3&D4 are forward biased and D1&D2 are reverse biased. Therefore load current flows through D3&D4 diodes.
This type of rectifier circuit uses a transformer with secondary winding tapped at the centrum point. Two diodes are connected in the circuit so that each one of them uses a one-half cycle of the input AC voltage. For rectification, one diode uses the ac voltage showing the upper half of the secondary winding while other diode uses the lower half of the secondary winding. The o/p and efficiency of this circuit are high because the AC supply brings power throughout both halves.
Comparison Of Rectifiers:
The comparisons between different types of rectifiers on the different points are tabulated below.
|Properties||Half wave rectifier||Full-wave center-tap rectifier||Full-wave bridge rectifier|
|Number of Diodes||1||2||4|
|Direct Current||Im / π||2 Im / π||2 Im / π|
|Max Value of Current||Vm / (rf + RL)||Vm / (rf + RL)||Vm / (2rf + RL)|
|O/p Frequency||fin||2 fin||2 fin|
|Peak Inverse Voltage||Vm||2 Vm||2 Vm|
Applications Of Rectifiers:
Essentially, almost all electronic circuits operated on DC voltages. The main goal of using a rectifier is for rectification which means converting AC voltages to DC Voltages. It’s means, rectifiers are used in almost all power rectification and electronics appliances.
Below is the list of common applications and uses of different Rectifiers.
- Rectification i.e. converting DC Voltages to AC Voltages.
- Rectifiers are used in electric casting to provide the polarized voltage.
- It is also used in traction, rolling stock, and three-phase traction motors used for running trains.
- Half-wave rectifiers are used in mosquito repellent and soldering iron.
- Half wave rectifier also used in Amplitude modulation Radio as a detector and signal peak detector.
- Rectifiers also used in modulation, demodulation, and voltage multipliers.