A symbol is a simple graphical representation of some type of component, device, and load that can be drawn easily on a two-dimensional scale. On electrical or electronic diagrams, symbols are used to represent electrical components. Electrical symbols used in industry today are what engineers use to identify parts of …

Read More »## Sinusoidal Waveform or Sine Wave in Electricity

Because of the importance of sinusoidal functions, I will devote this section to a review of some of their properties. Let us being with the sine wave, $\begin{matrix} v(t)={{V}_{m}}\sin (\omega t) & \cdots & (1) \\\end{matrix}$ Which is sketched in figure (1). The amplitude of the sinusoid is Vm, which …

Read More »## Electric Current | Unit of Electric Current

The primary purpose of an electric current is to move or transfer charges along specified paths. This motion of charges constitutes an electric current, denoted by the letters i or I, taken from the French word “intensite”. Formally, The basic unit of current is the ampere (A), named after …

Read More »## Phasors in Electric Circuits

The phasor method of analyzing circuits is credited generally to Charles Steinmetz, a famous electrical engineer with the General Electric Company in the early part of this century. To begin, let us recall the general sinusoidal voltage, $\begin{matrix} v={{V}_{m}}\cos (\omega t+\theta ) & \cdots & (1) \\\end{matrix}$ If the frequency …

Read More »## RMS Value| RMS Voltage | RMS Current

Periodic currents and voltages deliver an average power to resistive loads. The amount of power that is delivered depends on the characteristics of the particular waveform. A method of comparing the power delivered by different waveforms is therefore very useful. One such method is the use of RMS or effective …

Read More »## RLC Series Circuit Analysis

When resistance, inductance, and capacitance are connected in series, the circuit is said to be RLC Series circuit. In the RLC Series circuit shown in the figure below, the current is common to all components. The series RLC circuit, shown in figure 1, is the dual of the parallel circuit. …

Read More »## Average Power Formula | Instantaneous Power Formula

In linear networks which have inputs that are periodic functions of time, the steady-state currents and voltages produced are periodic, each having identical periods. Consider an instantaneous power $\begin{matrix} p=vi & \cdots & (1) \\\end{matrix}$ Where v and i are periodic of period T. that is, $\begin{align} & v(t+T)=v(t) \\ & …

Read More »## Parallel RLC Circuit Analysis

When resistance, inductance, and capacitance are connected in parallel, the circuit is said to be RLC Parallel circuit. In the parallel RLC circuit shown in the figure below, the supply voltage is common to all components. One of the most important second-order circuits is the parallel RLC circuit of figure …

Read More »## Inductor Types and Symbols

In spite of the great number of different kinds of inductors, only a few schematic symbols are needed to represent them. Filter Choke A filter choke for a power supply is shown in figure 1 (a), and its symbol is shown in figure 1(b). Fig.1: Iron Core Choke Coil: (a) …

Read More »## RL Circuit Time Constant | Universal Time Constant Curve

When a series RL circuit is connected across a supply, voltage and current transients occur until the current attains a steady-state condition. Consider the circuit figure 1, where R represents the coil’s resistance or an external resistance. When the switched is closed, current begins to flow into the inductance. The …

Read More »## RC Circuit Time Constant | Charging Discharging of Capacitor

When a discharged capacitor is suddenly connected across a DC supply, such as Es in figure 1 (a), a current immediately begins to flow. At time t1 (Figure 1 (b)), the moment the circuit is closed, the capacitor acts like a short circuit. The in-rush current iC is at its …

Read More »## Capacitor Types | Fixed and Variable Capacitors

Variable capacitors Variable capacitors are distinguished by the fact that their capacitance can be changed. Basically, there are two most common types of such capacitors named as a trimmer and rotor-stator capacitors. Rotor-Stator Capacitor The rotor-stator type of capacitor comprises two metallic plate sets. The moving plates are attached conjointly …

Read More »## Ohm’s Law Definition | Ohm’s Law Formula

Ohm’s Law Definition Ohm’s law states that the current in an electric circuit is proportional to the applied voltage and inversely proportional to its resistance. As the voltage increases in a circuit (resistance remaining constant), the current increases by the same amount. Hence, if the voltage is doubled, the current …

Read More »## Capacitive Reactance in AC Circuit

Capacitive Reactance The AC Current flow in a capacitor depends on the supply voltage and the capacitive reactance. The capacitance value and the supply frequency determine the capacitive reactance. The alternating current through a capacitor leads the capacitor terminal voltage by 90o as shown in the figure below. If a …

Read More »## Inductive Reactance in AC Circuit

Inductive Reactance Alternating current flow in an inductor depends on the applied voltage and on the inductive reactance of the inductor. The inductive reactance is proportional to the inductance value and the frequency of the alternating supply voltage. When an alternating voltage is applied to a pure inductance, the current …

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