Current inrush phenomenon in transformer is the flow of high magnetizing current for short time in primary winding when the transformer is switched ON at the instant when applied voltage is zero.
What is Transformer Inrush Current? Waveform, Nature & Problems Read More »
Figure 1: Sumpner’s Test (Back to Back Test) of Transformer. Sumpner’s test is the improved method of determining the regulation, efficiency and heating on load conditions than O.C and S.C tests. This test requires two similar transformers, which can be connected to the supply in such a way that one is loaded on other. The
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Depending upon the type of core used there are two types of transformers in practice. They are, Core type transformer Shell type transformer. Core Type Transformer Figure 1: Core Type Transformer.
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A single phase non-salient pole synchronous motor with no D.C excitation is known as hysteresis motor. This motor is so called because it runs on torque produced by the hysteresis loss induced in the rotor. Figure 1: Hysteresis Motor.
What is Hysteresis Motor? Working, Diagram, Construction & Applications Read More »
We know that the expression for torque of an induction motor under running condition is given by, \[T=\frac{KsE_{2}^{2}{{R}_{2}}}{R_{2}^{2}+{{(s{{X}_{2}})}^{2}}}\]
Maximum Torque of Induction Motor – Derivation & Condition Read More »
A constant voltage transformer (CVT) works on ferro-resonant principle. The variation in the primary flux with an unsaturated iron core does not affect the secondary flux with saturated iron core. Thus, the secondary induced voltage remains relatively independent of the voltage impressed upon the primary winding. Fig. 1: Constant Voltage Transformer (CVT).
What is Constant Voltage Transformer (CVT)? Working Principle, Diagram & Applications Read More »
The lamps in which the light is produced due to the how of electrons through the gas are known as the gas discharge lamps. Mercury Vapour Lamp is a gas discharge lamp. It has high operating pressure with mercury vapours, so it is called as the high pressure mercury vapour lamp. Figure 1: Mercury Vapour
What is Mercury Vapour Lamp? Working, Diagram, Construction & Uses Read More »
Megger is a portable instrument for measuring high resistances in which the voltage range can be controlled by using a voltage selector switch. It is not only used for measurement of high resistances (insulation resistance), but also can be used for testing of insulation resistance. One more advantage is that deflection of the instrument is
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It is also the gas discharge lamp in which sodium is used, so this is called as the sodium vapour lamp. Fig. 1. Sodium Vapour Lamp.
What is Sodium Vapour Lamp? Working, Diagram, Construction & Uses Read More »