## Ideal Transformer | Theory | Equations | Example Problems

In all transformers, single phase or three phase, the primary winding gets energy from the mains and the secondary winding is connected to the load(s). If the secondary circuit is turned off by a switch, there is no load on the secondary winding. Ideal Transformer Theory Nevertheless, the primary winding is …

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## Single-Phase Transformer | Construction | Theory

In the same way that single-phase AC and three-phase AC are different, although both are alternating current electricity, single-phase and three-phase transformers cannot be interchanged. Nevertheless, most of what can be said for single-phase transformers is later on extended to three-phase transformers because they work based on the same principle. …

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## Effect of Temperature on Resistance | Temperature Coefficient of Resistance

Checking the voltage/current (V/I) ratio of conductors at various temperatures shows that the resistance of most conducting materials increases linearly with temperature except at very hot or very cold temperatures. Temperature has little effect on the resistance of some alloys, such as constantan. For a few materials, including carbon and …

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## Three-Phase Balanced Load | Delta and Wye Connected Loads

A three-phase load is a set of three exactly similar combinations of electric components arranged in exactly the same way (in series, parallel or other). The reason to have three-phase loads is the higher power demand. For instance, in the industry, the majority of motors are three phase, particularly the …

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## Three-Phase System Theory Explained | Star and Delta Connection

The fact that the three waveforms of a three-phase system are 120° apart gives desirable properties to it that makes it attractive from a practical viewpoint.  The very first property of the voltages in the three-phase system is that at each instant of time the sum of all the voltages …

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## Resonance in Series and Parallel RLC Circuit

In any AC circuit consisting of resistors, capacitors, and inductors, either in series or in parallel, a condition can happen in which the reactive power of the capacitors and of the inductors become equal. This condition is called resonance. Simultaneous with the capacitive reactive power and the inductive reactive power being …

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## Phase Relationships in AC Circuits | Phase Difference | Phase Shift

Phase Difference When we have two sine waves with the same frequency, the duration of one cycle is the same for both. Nonetheless, irrespective of their peak values, there are two possibilities: 1. The two waveforms reach their maximum values (and accordingly their minimum values) at the same instant. In this …

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## Relationship between Voltage Current and Resistance

The fundamental relationship between resistance, voltage, and current can be expressed using Ohm’s law. Mathematically, it is expressed as: $V=IR$ Where, V is measured in Volts I is measured in Amps R is measured in Ohms Electric Current The electric current is a measure of the rate of flow (i.e., …

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## 741 Operational Amplifier (Op-Amp) | Basics, Characteristics & Pin Configuration

One of the most commonly used integrated circuit chips today is the operational amplifier. The operational amplifier is often simply called the op-amp. 741 Operational Amplifier Characteristics The 741 op-amp is a near-perfect amplifier. It has a high input impedance and a low output impedance, which makes it an excellent …

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## Integrated Circuit (IC) | Construction, History & Types

Definition: An integrated circuit, or IC, is a complete electronic circuit contained in one package, Figure 1. This package often includes transistors, diodes, resistors, and capacitors along with the connecting wiring and terminals. An IC is also called a chip. The transistor was invented in 1947 by Brattain, Bardeen, and …

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## Common Emitter Amplifier: Working & Circuit Diagram

Amplifier Definition: An amplifier is an electronic device that uses a small input signal (voltage or current) to control a larger output signal. This principle works best when the output load, or impedance, of the circuit, is greater than the input load. Examine Figure 1. The input is a microphone …

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## Transistor as an Amplifier: Working & Circuit | NPN Transistor Amplifier

Definition: An amplifier is an electronic circuit that uses a small input signal to control a larger output signal. In electronics, amplifiers have been used since the early twentieth century. Amplification can be accomplished using vacuum tubes or semiconductor devices such as transistors or integrated circuits. The amount of amplification …

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## Field-Effect Transistor (FET) Types | JFET & MOSFET Construction

The major difference between bipolar junction transistor and field-effect transistor (FET) is that the BJT is a current device, and the FET is a voltage device. The current through the collector-emitter circuit of a BJT is controlled by the amount of current in the base-emitter circuit. A FET controls current …

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## NPN Transistor Working Principle

The scientists John Bardeen and Walter Brattain invented the point-contact transistor. It had two wires carefully fused on a crystal of germanium. William Shockley followed these inventions by creating the bipolar, or junction, transistor. These inventions were the beginning of microelectronics. The transistor provided instant circuit operation and eliminated the …

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## Voltage Regulator: Working Principle & Circuit Diagram | Voltage Regulator in Power Supply

The output voltage of a power supply will usually decrease when a load is applied. This decrease is not good and needs to be minimized. The size of this decrease is measured in comparison to the no-load voltage. The voltage decrease under load compared to the power supply voltage with …

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