![]() As I am sure you are aware, dimming in this case, is the process by which we vary the light output of an LED. Since we are, of course, referring to light output, then it is safe to say we are referencing some form of dimming. If you recall, I briefly mentioned that PWM is ideally suited as a controlling methodology for LEDs due to the linear fashion in which their functionality is affected by their input voltage. By quickly switching the output voltage of say, an inverter leg between the upper and lower voltages (DC rail), the low-frequency output basically becomes the average voltage over the switching period. PWM is a methodology or technique to generate low-frequency output signals from high-frequency pulses. PWM is also currently in specific communication systems as well, and its duty cycle is in use to convey information over communications channels. In general, the intrinsic nature of digital technology lends itself effortlessly to the functionality of PWM, and thus it is easy to set the necessary duty cycle. This is due to the nature of digital technology as a whole, i.e., 1’s and 0’s or On and Off states. Moreover, PWM is also ideally suited for digital controls as well. Therefore, since power loss is a consequence of both voltage and current, this equates to a near-zero loss in power for PWM. Pulse Width Modulation Functionality and Applications Continued Also, during the on phase of a switch, while transferring power to its load, there is practically no drop in voltage across the switch. In fact, during the off phase of a switch, there is virtually no current. Furthermore, one of the significant advantages of using PWM is that power loss in the switching devices is substantially low. For example, the switching has to be done several times a minute in say an electric stove and well into the tens or hundreds of kHz for PC power supplies and in audio amplifiers. In general, the frequency in which the power supply must switch will vary widely depending on the device and its application. Furthermore, the PWM switching frequency needs to be high enough as not to affect the load, yet the resulting waveform that the load perceives should also be smooth. Also, this is equally true for LEDs because of the linear fashion in which their functionality is affected by their input voltage. However, PWM is especially suited for running inertial devices like motors, which are not as quickly affected by this distinct switching. For example, PWM paired with maximum power point tracking or MPPT is one of the principal methods for reducing the output of solar panels to facilitate its use by a battery. As you might imagine, this type of control has many useful applications. Pulse Width Modulation Functionality and Applicationsįurthermore, when comparing the on and off periods of the switch in use, increasing the on-time versus the off-time increases the total power supplied to the load. ![]() Also, in terms of functionality, control over the average current and voltage delivered to the load is achieved by rapidly turning the switch between the load and the source, on and off. Furthermore, the process is achieved by effectively chopping up the signal into distinct parts. PWM is a method that reduces the average amount of deliverable power of an applied electrical signal. ![]() So, what does the functionality of the methodology of PWM entail? Overall, PWM signals are in use for dimming LEDs, controlling motors, and various other electronic devices. What prompts such extensive use of PWM in today’s field of Electronics is, of course, its ability to lend control over numerous devices within every subdivision of the area of Electronics. Moreover, PWM finds itself in extensive use in today’s vast area of Electronics. Furthermore, in terms of use, there is one variation of modulation control in use in the field of electronics, it is called Pulse Width Modulation, or PWM. Therefore, it is only logical that a method such as this will find a wide variety of uses. Times like those were when I really appreciated having test subjects, or should I say older siblings.Īs defined earlier, modulation is, in essence, about control. It is the second definition that my parents typically made use of. This secondary definition I am referring to is the variation in the tone, pitch, or strength of one's voice. However, there is a second definition for modulation that I am sure most of us are familiar with as well. Modulation in terms of a definition is the application of a controlling or modifying influence on someone or something.
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