Advantages and Disadvantages of Pulse-Width Modulation (PWM)
In most communication systems, a signal’s amplitude is typically directly encoded for transmission into another signal’s pulse width or length, typically a carrier signal. The name of this technique is pulse-width modulation (PWM). PWM is used during communication but also to manage the power supplied to various electrical devices, especially to inertial loads like AC/DC motors.
It modulates the amplitude of digital signals by operating hardware and software that needs power or energy, and it modulates amplitude of digital signals. Pulse-width modulation (PWM) adjusts the amplitude of digital signals to run devices and software that demand electricity or power. By rapidly switching the on and off phases of a digital signal, PWM effectively regulates the amount of power delivered to a device in terms of the voltage component.
PWM circuits commonly employ both a large and a very small power supply. To further simplify things, The smaller power source regulates the larger one by using power transistors.
The tiny transistor creates the signal, and the transistors, as mentioned above, regulate the “power,” or the massive current and voltage that turn on the LED. That little power source could be a GPIO pin of a microcontroller, such as an Arduino 1/O pin or the output pin of a 555 timer, among others.
Since the huge current is merely an amplified version of the tiny current, setting the signal’s duty cycle to 30% will also result in a duty cycle of 30% for the power (which is the signal).
Kinds of Pulse-Width Modulation (PWM) techniques
There are three types of Pulse-Width Modulation (PWM) techniques:-
Lead Edge Modulation– With this technique, the signal’s lead edge is fixed while the tail edge is modified.
Trail Edge Modulation– This technique modulates the lead edge of the signal while leaving the trailing edge fixed.
Pulse Center Two-Edge Modulation– This method fixes the pulse’s core while modulating both of the pulse’s edges.
Importance Of Pulse-width Modulation (PWM)
- PWM techniques are used in communications to encrypt data.
- In lighting systems, pulse width modulation controls motor speed and brightness and assists in voltage regulation.
- Computer motherboards require PWM signals to control the heat the board generates.
- A 4 Pin PWM header is fitted into the fan that helps the motherboard dissipate heat. Devices such as audio/video amplifiers and others make use of it.
- PWM is a widely used control method that converts digital signals from gadgets like microcontrollers into analog signals. However, instead of using an analog signal that is constantly changing, PWM divides the signal’s energy over several pulses.
Advatages Of Pulse-width Modulation (PWM)
- The cost of construction is meager.
- It has a vast capacity for power handling.
- It operates with hardly any heat production.
- Very little noise interference is present.
- A less powerful filter is necessary.
- It can operate at very high frequencies.
- PWM is a system that is moderately inefficient in all three areas.
- PWM has significantly lower total harmonic distortion of the load current.
- 90% or greater efficiency
- PWM is a system that demonstrates all three varieties of moderate inefficiency.
- During the demodulation stage, signal and noise can be easily distinguished.
- Compared to other processes of a similar nature, it uses a lot less energy.
- Amplitude and frequency can be controlled relatively independently.
- Pulse width modulation offers accuracy and quick response times.
Disadvantages Of Pulse-width Modulation (PWM)
- Its working circuit and procedure are both intricately designed.
- Voltage surges occur frequently.
- There is electromagnetic noise.
- The issue of radiofrequency interference exists.
- PWM frequency results in high switching loss.
- A substantial bandwidth is used for communication.
- In the circuit, the variation in the immediate power of the transmitter is used.
- The system requires a semiconductor device with a relatively low turn ON and turn OFF frequency. Thus, even though it’s cheap to build, the output is expensive.
Pulse-Width Modulation (PWM) is frequently used in the voltage control technique. The PWM method removes power from the input at regular intervals in an amount equal to the power that must be output. The filtering process is made simpler by the constant frequency used in PWM control, which makes it possible to anticipate any switching noise. However, constant frequency has the issue of continuously consuming current due to the same number of switching operations being performed regardless of how much or how little load is supplied.
Due to this, switching loss predominates during periods of low demand, significantly decreasing efficiency. It is obvious why it is the most widely utilized process. Technology will surely grow more valuable as it develops in various industries. Fortunately, those drawbacks will have vanished by then. With the Pulse-Width Modulation (PWM) concept, other computers and sophisticated microcontrollers, or MCs, can now regulate very large currents at a reasonable cost. The signal that the microcontroller/MC generates is used to regulate a power transistor.