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Voltage Changes in Electrical Power System

Voltage changes in an electrical power system may be categorized as momentary, temporary, or sustained.

AC generators are designed to produce a rated output voltage. In addition, all electrical and electronic equipment is rated for operation at a specific voltage. The rated voltage is a voltage range that was normally ±10%. Today, however, with many components de-rated to save energy and operating cost, the range …

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Oscilloscope Working Principle | Oscilloscope Parts and Function


Oscilloscopes come in a variety of brands and complexities. Two general categories of oscilloscopes include those used for general-purpose bench work applications, and the more complex (and expensive) laboratory-quality oscilloscopes, Figure 1a and b. A portable scope is shown in Figure 1c. Figure 1: (a) General-purpose oscilloscope; (b) lab-quality oscilloscope; …

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Power Transformer Characteristics

Power transformers

Power transformers, Figure 1, typically have the following features: They are heavy (because of their iron core) and can be very large, like the transformers on telephone poles. However, power transformers in electronic devices are much smaller and vary considerably in size. They have a laminated iron core to reduce …

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Transformer Ratios of Single-Phase Transformers

Figure 4. Diagram using standard electrical symbols to show the AC supply, a single-phase transformer, and its connected load in an electrical schematic

In a given single-phase AC transformer, whether auto, isolation, or current type, there are three principle transformer ratios: the current ratio, the turns ratio, and the voltage ratio. The ratios of both current and voltage are dependent on the turns ratio, which is established at the point of manufacture (by …

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Electric Motor Load

As shown in Figure 1, the installations and uses of electric motors are just as diversified as the many different kinds and horsepower ratings of electric motors. In general, electric motors or electrical utilization equipment that contains motor loads must be provided with a disconnecting means, supply conductors, and some …

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Purpose of Grounding the Utility Power Distribution

fig 1 The static ground wire in the 3-phase electrical utility power transmission-distribution grid

The transfer of electrical power within the electrical-utility power transmission/distribution grid is normally at high voltage (high tension) to reduce the transmission losses (line losses) along the miles of cable that must be installed between the generating plants and the many cities, commercial and industrial sites, and suburban, as well …

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