In electrical engineering, the power factor of an AC system is the expression of energy efficiency. The power factor (PF) is defined as the ratio of active power (measured in Watts) to the apparent power (measured in VA). The power factor expresses the ratio of true power which is used ... Read More

An SCR is a three-terminal, three-junction, and four-layer semiconductor device that is used to perform switching functions in power circuits.Sometimes the SCR is also called as Thyristor.Constructional Details of SCRThe SCR has three pn – junctions, and four layer of p and n type semiconductor joined alternatively to get pnpn ... Read More

A synchronous motor is not inherently self-starting. Therefore, it requires some auxiliary means of starting. In order to start a synchronous motor, there are following two methods −Starting with an external prime moverStarting with damper windingsSynchronous Motor Starting with an External Prime MoverIn this method of starting a synchronous motor, ... Read More

There is a category of transistors called Field Effect Transistor (FET). In this category, a lot of field effect transistors are there like Junction Field Effect Transistor (JFET), Metal Oxide Field Effect Transistor (MOSFET), Metal Semiconductor Field Effect Transistor (MSFET), etc. In this article, we will compare and contrast the ... Read More

An electrical transformer is tested at the transformer manufacturer premises and at the consumer’s site and also periodically in regular and emergency basis during its service life to confirm its specifications and performance.Types of Transformer TestsTests of transformer done at the manufacturer’s premises −Type testsRoutine testsSpecial testsTests of transformer done ... Read More

In an AC electric circuit, when the capacitive reactance is balanced by the inductive reactance at some given frequency, then this condition in the circuit is referred as resonance. The frequency of the supply voltage at which resonance occurs in the circuit is called resonant frequency. At the resonance in the ... Read More

When the transformer is in operation, heat is generated due to copper losses in the windings and iron losses in the core. The removal of heat from the transformer is known as cooling of the transformer.Transformer Cooling MethodsFor the dry type transformersAir Natural (AN) CoolingAir Forced (AF) or Air Blast ... Read More

Full Wave Rectifier is a diode circuit which is used to transform the complete cycle of Alternating Voltage (AC Supply) to Direct Voltage (DC Supply).In full wave rectification, current flows through the load in the same direction for the complete cycle of input AC Supply.Types of Full Wave RectifiersCentre Tap ... Read More

Operating Principle of Single-phase Induction MotorA single-phase induction motor consists of a squirrel cage rotor and a stator carrying a single-phase winding. When a single-phase AC supply is fed to the stator winding, a pulsating magnetic field (not the rotating) is produced. Under these conditions, the rotor does not rotate ... Read More

Half Wave Rectifier is a diode circuit which is used to transform Alternating Voltage (AC Supply) to Direct Voltage (DC Supply). A single diode is used in the HWR circuit for the transformation of AC to DC. Half Wave Rectifier circuit allows the one – half cycle of the AC ... Read More