A diode is a two terminal semiconductor device which allows the current to flow when it is forward biased and blocks the current when it is reverse biased. Rectifier is a circuit which consists of a diode which has higher current carrying capability and thus used for rectification of AC signal.The major difference between diode and rectifier is that the diode is a device which becomes short circuit when it is forward biased and open circuit when it is reverse biased.
On the contrary, a rectifier is a device which is used for the conversion of AC signal into DC signal.
The other crucial difference between diode and rectifier is that both are used for different application. When we want a switch we will use a diode. On the other hand when we need to convert AC into DC then we will use a rectifier.
You all are aware of the utility of a switch. But you may or may not know the use of rectifier in our daily routine. Now you all must be thinking what is that? Let me tell you the most indispensable part of our day to day life i.e. our mobile phones; it needs a rectifier for charging. The charger of our mobile phones comprises a rectifier circuit.
The AC supplied to the rectifier is converted into pulsating DC and that is used for the charging of our mobile phones. We will discuss some more differences between diode and rectifier with the help of comparison chart but before that, let’s put light on the roadmap of this article.
Content: Diode and Rectifier
|Defintion||A diode is a semiconductor device which conducts when it is forward biased and becomes open circuit when it is reversed biased.||Rectifier is circuit which consists of diode, step-down transformer and filter circuit which collectively converts AC into pulsating DC.|
|Structure||It is a semiconductor device but a single element or entity in an electronic circuit.||Rectifier itself is an electronics circuit which consists of several elements as its components; among which diode holds crucial place.|
|Current Carrying Capability||Low in normal diodes.||Rectifier diodes has higher current capability then the conventional diode.|
|Types||Tunnel diode, PIN diode, Photodiode, Zener diode etc. are the various types of diodes.||Rectifier are basically divided into two categories that are single phase and 3-phase recitifier, and single phase is also further subdivided into half-wave and full-wave rectifier.|
|Applications||Diodes are used in switches, clippers, clampers etc.||Rectifies are used in computers, battery chargers, modulators, demodulators etc.|
A diode is formed by combining a specimen of the P-type semiconductor and N-type semiconductor, and the junction thus formed is termed as PN junction. The majority carriers from one side of PN junction flow through another junction.
A stage is reached when no more charge carriers flow towards another junction. This is because they do not possess sufficient energy which is required to overcome the potential of the junction. In this condition, the diode will work only when it is supplied energy from any external source such as a battery, cell etc.
When the positive terminal of the battery is connected to the P-terminal of the diode and the negative terminal of the battery is connected to N-terminal the of the diode then the depletion layer starts contracting. This is due to repulsion of majority charge carriers from either side of the junction.
Due to the above-explained phenomenon, the conduction process is triggered in the diode. When the negative terminal of the battery is connected to the positive terminal of the diode and positive terminal of the battery to the negative terminal of the diode, the width of the depletion region starts increasing. As a consequence of which the barrier potential increases and current conduction ceases.
A rectifier is a device which converts AC signal into DC signal. The DC output obtained from the rectifier is not pure DC but it consists of AC ripples. Thus, the rectifier circuit also consists of a filter which removes the AC ripples from DC output.
The AC applied to the rectifier for conversion is high voltage AC, because AC voltage is always supplied in high magnitude. It is economical to transmit it in high voltage range. But it is not possible for a rectifier to process such a high magnitude AC, thus a step-down transformer is connected at the input side. It lowers the magnitude of applied AC voltage.
Basically, there are two types of rectifier, one is single phase and the other is 3-phase. The subdivided category of these are the half-wave and full-wave rectifier. Half-wave converts half cycle of AC into DC while full-wave converts full cycle of AC into DC.
Key Differences between Diode and Rectifier
- The key difference between diode and rectifier is that the diode is a semiconductor device which conducts uni-directionally and acts as a switch. On the contrary, the rectifier is the semiconductor device which converts alternating current into pulsating direct current.
- Another crucial difference between diode and rectifier is the current carrying capability of both the normal diode and the rectifier diode. The rectifier diode has more current capability than a normal diode.
- The diodes are used in clipper, clamper, switching circuit etc. while the rectifiers are used in phone chargers, communication circuits, DC motors etc.
The diode and rectifier, both are semiconductor device but are used in different application due to their different functioning.