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Types of Pulse Modulation

Modulation of Pulse width is a term of physics that describes the method of reducing the average power that is delivered by an electrical signal.

Pulse width modulation suggests a particular modulation process that is used in the majority of the communication system in order to encode the amplitude of a signal. In a simple manner, it can be described as the technique that has been followed for controlling the range of a digital signal for controlling the devices. Following these particular facts, the current study will include an overview of the Pulse Width Modulation in order to represent the term in a more understandable manner. 

Definition of Pulse Width Modulation

In electronics, the term modulation refers to the application of altering or controlling influence on something. Based on this particular definition, pulse width modulation has been referred to as the specific kind of technique that is used in reducing the average power that has been delivered by an electrical signal. In the occurrence of this typical situation, it has been observed that the average value of voltage that has been fed to the load can possibly be controlled by turning the switch between the load and supply. The duration of the switching is one of the primary methods of reducing the average power. 

Pulse Width Modulation Techniques

There are six kinds of Pulse width modulations techniques that are mentioned in the below section:

  • The single pulse width modulation technique has been used for singular-phase circuits. In such situations, the gate signal of the transistor is controlled in order to control the output voltage of the inverter. 
  • If the inverter consists of multiple phases per half cycle, the modulation will be the multiple pulse width modulation
  • In industrial applications, sinusoidal pulse width modulation has been used
  • Apart from the above-mentioned ones, Hysteresis band pulse width modulation and space vector pulse width modulation are popular in use. 

Pulse Width Modulation Frequency

In general, pulse width modulation is primarily suited for running devices such as motors. Motors are taken as the most suitable ones because the motors cannot be affected more quickly by distinct switching. On the other hand, the frequency of the pulse width modulation needs to be high in order to not create any effect on the load. The switching of the frequency commonly depends on the device and its application. 

Characteristics of Pulse Width Modulation 

In order to understand the behaviour of the PWM, two primary concepts include frequency and the duty cycle. The fraction of one period when a signal is active is recognised as the term of duty cycle. This duty cycle has been represented as a ratio or in a percentage. On the other hand, frequency is defined as the particular rate that is recorded in the repetition of something over a particular period. In a more simple diction, it can be represented as the particular rate of the vibration that creates the wave.   

Pulse Width Modulation – Principle of Technique

The technique of generating the low-frequency output signals from pulses that are of high frequency has been recognised as the usual term for pulse width modulation. It actively switches into upper and lower voltages within DC rails from the output voltage of the leg of an inverter. Including analogue signals, several ways of generating pulse width modulation signals exist such as sigma modulation, and direct digital synthesis. Comparing two kinds of signals that are career signals and modulation signals has been seen as the simplest method for the generation of a pulse width modulation signal. 

Advantages of Pulse Width Modulation

The advantage of the pulse width modulation includes the fact that it is cheap to make. In addition, low power consumption has been recorded as one of the main advantages of pulse width modulation. Besides these, the efficiency of the pulse width modulation is nearly 90% which showcases the high power handling capacity.  In addition, this is able to utilise the high frequency of the pulses. Therefore, the noise interface becomes less. On the contrary, this reduces the requirement for a filter that contributes to controlling the frequency and amplitude in an independent manner. 

Conclusion 

The current study has shed light on the discussion that is based on the representation of the facts regarding Pulse Width Modulation. Furthermore, in this study, it has been found that the discussion is conducted by focusing on the different types of PWM techniques like single pulse width modulation technique, multiple pulse width modulation and many more. Moreover, this study has magnified the advantages of Pulse Width Modulation based on the different circumstantial requirements.

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Frequently asked questions

Get answers to the most common queries related to the UPSC Examination Preparation.

What is Pulse Width Modulation used for?

Ans. In a common manner, the Pulse Width Modulation has been used for controlling the speed of an electrical motor&#...Read full

Which modulation technique is used for the control of output voltage in the PWM inverter?

Ans. Modulation in an inverter includes the adjustment of the off and on the duration of the inverter switch under t...Read full

What is the main disadvantage of Pulse Width Modulation?

Ans. Following the information, Pulse Width Modulation has several disadvantages including voltage spikes. The compl...Read full

How is Pulse Width Modulation generated?

Ans. In a usual manner, in order to generate the Pulse Width Modulation, a Comparator is used. Modelling signal form...Read full