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Basics of Diode

The diode consists of two terminals, the first one is the anode and the second one is the cathode. It used to allow current to flow in one direction only, by offering less value of resistance in one direction and high in the other.

A diode has 2 terminals called electrodes and the diode has a PN junction, one side of the junction is N which has a high concentration of electrons and the other side is P which contains a high concentration of holes.

The diode is generally created with the use of silicon but other materials such as arsenide germanium are also used.

Diodes can be used in rectifier circuits to transform ac to dc and also for demodulation in radio systems.

Another form of the diode is an LED that is used in the lighting system to illuminate the environment. 

Working of diode

Its main operation is to move the current in a single direction in one polarity and not allow current in the backward direction. There are two modes of operation first one is forward biased and the second one is reverse biased. In forwarding biased current flow and reverse biased not flow.


Symbol of diode

Ideal diode

The main operation of the ideal diode is to regulate the direction of the current. Current moving in the diode can move in a single way and if tries to move backwards then it is blocked., this process is like the one-way valve.

If voltage is applied to the diode in a negative value there is no current in the diode for this state it is called a reverse-biased state. Diode works as an open circuit

If the voltage applied to the diode is in the positive state then current flows and the diode operates as a short circuit and is in forward biased state.

What is forward voltage?

When a positive voltage is applied to the diode it will turn on and the current will flow, the voltage needed to turn on is called forward voltage denotes and denoited as Vf

What is breakdown voltage?

If a negative polarity voltage is applied to the diode then the current starts to flow in the reverse direction. That certain value of volts in a negative direction is called the breakdown voltage.

Small signal diode

Is a type of diode that needs a small value of signal to operate. The area of pn junction for this diode is small. So less charge storing capacity for this junction. So this diode offers a high switching speed with less recovery time.

Rectifier diode

This diode has a larger pn junction area. So it offered a larger value of capacitance in the reverse direction. Its switching speed is also low. This category of diode is very common due to its ability to handle larger current used as rectifiers.


The main applications of diodes are listed here

  • Used in rectifiers
  • Used in logic gates
  • Used in battery
  • Used in UPS
  • Used in communication system'

Types of diode

There are different types of diodes that are commonly used in industrial and electronic projects


That is all about the diode, I have explained all the basics of the diode if you have any further questions, ask in the comments. Thanks for reading

I am a professional engineer and graduate from a reputed engineering university also have experience of working as an engineer in different famous industries. I am also a technical content writer my hobby is to explore new things and share with the world
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