Rectifier

Rectifiers have a wide range of applications, although they’re most commonly used in DC power supply and high-voltage direct current power transmission system specification can be utilised for more than only producing direct current for power generation. Rectification can be utilised for more than only producing direct current for power generation. The output voltage may require further smoothing to generate a uniform steady voltage, depending on the type of alternating current supply and the design of the rectifier circuit.

We need DC voltage to operate a huge number of electronic circuits. Using a device known as a p-n junction diode, we may simply change AC voltage or ACcurrent into DC voltage or DCcurrent.

The conversion of Alternating Current (AC) into Direct Current (DC) is one of the most important applications of a p-n junction diode (DC). A p-n junction diode enables electric current only when it is forward biased and blocks it when it is reverse biased. A diode, in simple terms, allows electric current to flow in just one direction. The diode’s unique characteristic allows it to function as a rectifier.

Forward biased

The diode is said to be forward biased when the voltage is provided in such a way that the positive terminal of the battery is linked to the p-type semiconductor and the negative terminal of the battery is linked to the n-type semiconductor Whenever the forward bias voltage is applied to the p-n diode, the battery’s negative terminal repels a large number of free electrons (majority carriers) in the n-type semiconductor., while a huge number of holes (majority carriers) in the p-type semiconductor encounter a repulsive force from the battery’s positive terminal.

Reverse biased

The diode is said to be reverse biased when the voltage is provided in such a way that the positive terminal of the battery is linked to the n-type semiconductor and the negative terminal of the battery is linked to the p-type semiconductor. When this reverse bias voltage is given to the p-n junction diode, a huge number of free electrons (majority carriers) in the n-type semiconductor are attracted by the positive terminal of the battery, and a huge number of holes (majority carriers) in the p-type semiconductor are attracted by the negative terminal of the battery.

Since, there is no electric current flow across the p-n junction. Minority carriers (free electrons) in the p-type semiconductor, on the other hand, are repulsed by the negative terminal of the battery, just as minority carriers (holes) in the n-type semiconductor are repulsed by the positive terminal of the battery. The free electrons (majority carriers) in the n-type semiconductor shift away from the p-n junction and are attracted to the battery’s positive terminal, while the holes (majority carriers) in the p-type semiconductor shift away from the p-n junction and are attracted to the battery’s negative terminal.

As a result, the p-n junction diode admits electric current in forward bias but inhibits electric current in reverse bias. A p-n junction diode, to put it another way, only permits electric current to flow in one direction. The diode’s unique characteristic allows it to function as a rectifier.

Types of rectifiers

There are two types of rectifier. They are as follows:

Half wave rectifier

Half of the AC input signal (positive half cycle) is converted to pulsing DC output signal, while the remaining half signal (negative half cycle) is blocked or lost). Only a single diode is used in the half wave rectifier circuit.

Full wave rectifier

The full wave rectifier transforms the whole AC input signal (positive and negative half cycles) to a pulsing DC output signal. The input signal in a full wave rectifier is not lost like it is with a half wave rectifier. When compared to half wave rectifiers, full wave rectifiers have a higher efficiency.

Rectifier practical example

Almost all of the electrical items in our homes run on AC current. Some electrical gadgets, such as laptops and notebook computers, transform this AC current into DC current before using it.

The laptop’s AC adapter converts high AC voltage or high AC current into low DC voltage or low DC current when connected to an AC source. Laptop charging is the process of supplying a low DC current to the laptop battery. However, unless you manually switch on the laptop by pushing the on button, it will not turn on. when the battery starts supplying DC current when you press the “power on” button on your laptop.

rectifier circuit diagram

Full Wave Rectifier Circuit

The full wave rectifier circuit is made up of two power diodes that are linked to a single load resistance (RL), with each diode supplying current to the load in turn. Diode D1 conducts in the forward direction when point A of the transformer is positive in relation to point C,.

Diode D2 runs in the forward direction when point B is positive (in the negative half of the cycle) with respect to point C, and the current that flows through resistor R is in the same direction for both half-cycles. This type of full wave rectifier circuit is also called as a “bi-phase” circuit because the output voltage across the resistor R is the phasor summation of waveforms combined.

Conclusion

A rectifier is an electrical device that transforms alternating current (AC), which reverses direction on a regular basis, to direct current (DC), which only travels in one direction. Rectifiers have a wide range of applications, although they’re most commonly used in DC power supply and high-voltage direct current power transmission systems. A p-n junction diode enables electric current only when it is forward biased and blocks it when it is reverse biased. The full wave rectifier transforms the whole AC input signal (positive and negative half cycles) to a pulsing DC output signal.