Synchronous Motor Working Principle and Construction

Synchronous Motor Working Principle and Construction

Synchronous motor construction is very similar to synchronous generator construction except that most motors are salient-pole machines. Principle and Operation of Synchronous Motor When an induction motor is connected to a three-phase supply, a rotating magnetic field is established; this induces currents in the rotor windings, thereby producing a torque. The rotor can never turn at …

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Transformer Cooling Methods and Systems

Transformer Cooling methods

Transformer Cooling Methods A transformer in operation develops heat as a result of the copper and core losses during operation. Heat is not produced rapidly in small transformers, but the rate is much higher in large transformers. The rate of heat production determines how high the operating temperature rises above the ambient temperature. There are many  …

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Instrument Transformers Applications & Types

Instrument Transformers Application

Instrument Transformers Current transformer and voltage transformer measuring instrument transformers are designed to operate at low current and low voltage. Safety is also a reason for not connecting test instruments to sources operating at high voltage. An instrument transformer reduces high voltages and currents to safe values. Instrument transformers perform two functions. It serves as …

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Transformer Construction and Types of Cores

Transformer Construction

Basic Transformer Construction A transformer consists of two coils mounted in fixed positions relative to each other. One coil is supplied by an alternating current. As the current alternates, the magnetic field it produces also alternates. This alternating field induces an alternating current in the second coil, which supplies a load. A simple transformer construction consists …

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Transformer Losses and Efficiency

Efficiency of Transformer & Losses

Transformers have high efficiencies, especially the larger sizes operating at 50 to 100% of full load. However, they are not perfect. Some losses occur in all transformers. Transformer losses are divided into two types Copper losses Core losses Copper loss Copper loss is the loss of power caused by the resistance of the copper windings. …

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Dry Cells Characteristics & Sizes

dry cell sizes & properties

Dry Cell The potential difference between the terminals of a dry cell is about 1.5 volts (abbreviated V), regardless of the size of the cell. The potential difference depends only on the chemicals used in making the cell. The size affects only the length of time required for discharge. Dry Cell Size The larger the …

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