For AC-to-AC conversion the voltage and/or the frequency are the parameters that might need to be increased or decreased. For voltage only, a transformer can be used. But, for the frequency change, and for both frequency and voltage change, use of electronic converters becomes necessary. Unidirectional Back-to-Back Converters The key …

Read More »## Wind Turbine Parts and Functions

A wind turbine consists of five major and many auxiliary parts. The major parts are the tower, rotor, nacelle, generator, and foundation or base. Without all of these, a wind turbine cannot function. Foundation The foundation is under the ground for the onshore turbines; it cannot be seen because it …

Read More »## Number System and Base Conversion

The numbers we are familiar with and use every day are based on 10 symbols and rules for making and displaying all numbers, both positive and negative, from them. This system of numbers is the decimal system. Note that in the decimal system the base is 10; we have 10 …

Read More »## Variable Sampling

In the processes or machinery that are controlled by a microcontroller or microprocessor, all analog data must be converted to digital, so that it can be represented by binary numbers and be usable by the microprocessor. When a variable entity such as wind speed, car speed, or electric current in …

Read More »## One’s and Two’s Complement

For the analysis of practical applications, it is necessary to do mathematical operations on binary numbers. This is the basis of all that a microprocessor does. In this section, we study how two binary numbers are added, how one is subtracted from the other. We also discuss how the negative …

Read More »## Karnaugh Map Tutorial

An alternative to the truth table to determine and simplify the logic function for an application is Karnaugh map (K-Map), named after its originator Karnaugh. Karnaugh map abbreviates to K-map offers a simpler solution to find the logic function for applications with two, three, and four inputs. Its application to …

Read More »## Boolean Algebra Laws with Examples

The Boolean algebra is a set of specific rules that governs the mathematical relationships corresponding to the logic gates and their combinations. Their application is limited to two-valued (0 and 1) entries such as the inputs and outputs of logic gates. Dealing with one single gate and a pair of …

Read More »## Multiplexer and Demultiplexer

Multiplexer and demultiplexer are two devices very important in data communications. As the name implies, their functions are opposite to each other (similar to encoder and decoder). These devices are used for sharing a device between two or more applications. Consider, for instance, a decoder for seven-segment display. If we …

Read More »## Encoder and Decoder

Data can be stored in the form of binary numbers. Depending on the number of digits available, the magnitude of information stored changes, but more information can always be stored with less data. Having 4 bits of storage (say, four flip-flops), for example, offers the possibility of 24 = 16 …

Read More »## Flip-Flop in Digital Electronics

A flip-flop is the basic memory element for storing a bit of information. It is an edge-triggered device. That is, it reacts to the edge of a pulse. A simple flip-flop has two stable states (remember, for instance, that a capacitor has two states: charged and discharged). States are represented …

Read More »## Three Phase Transformer Connections

In this section, we’ll review the operating characteristics of basic delta-delta, wye-wye, delta-wye and wye-delta connections of the transformer. The construction of a three-phase transformer can be represented as shown in Figure 1. The shell type core has three sets of primary and secondary windings. How these windings are connected …

Read More »## Transistor Characteristic Curves

A fundamental property of a transistor and how it works is pointed out in the following Figure, where a transistor is correctly biased by two power supplies. Figure: Transistor Working with Two Power Supplies Figure 1 shows a simple circuit of a transistor, in which the 1.5 V battery and the …

Read More »## Residential and Industrial Solar Energy Systems

Solar rays reach the Earth at various frequencies and contain light and heat. Solar energy, thus, may basically be utilized in two different ways: absorbing light and absorbing heat. Heat can be directly used for warming and heating, in addition to generating electricity, whereas absorbing light can only be useful when …

Read More »## Transmission Line Effects

This section briefly describes matters concerned with transmission lines in electrical networks. Knowledge of the material described here is very useful for the technical personnel in electricity and its generation and distribution. Inductive and Capacitive Effect In addition to the ohmic resistance in the wires and electric conductors, conductors carrying …

Read More »## Fault Detection in Transmission Lines

Faults in an electric system can happen because of various reasons. Some faults in electrical distribution are due to natural causes such as lightning and are inevitable. Others can be due to deterioration of components as a result of age or abuse, and so on. What is important in operation …

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