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LITERATURE REVIEW

According to the English technologist, Misheal, J. (2005). Find out if

it is possible to build a security gadget that can guide unauthorized

usage of electrical power(DC)

Edison's direct current (DC) power system became the initial standard for distributed

electricity, powering electric railways and manufacturing motors as well as lighting.

Unfortunately, it could not be easily transmitted over long distances, which Tesla's

AC power system achieved. Implemented by Edison's competitor in electric power,

the Westinghouse Company, AC power superseded DC power and made possible the

development of large electrical generating plants sited long distances from customers.

Although Westinghouse's harnessing of hydropower at Niagara Falls with Tesla's

polyphase system is perhaps better remembered, developments in AC power

transmission from distant Sierra Nevada power sites in California to the coastal cities

of San Francisco and Los Angeles established the standard in long-distance polyphase

electric-power transmission.13

According to the researcher, Morris, C. J. (1980). Build a device that

can sense human shadow when standing close to the unauthorized

tapping detector in which it is mounted and blow an alarm each

time the body of the detector is touched to alert the owner.

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In 1982, a student from Havard University build an analogue meter

reading that can stop unauthorized tapping of electricity. It was a

welcome development but could not withstand the power of the

meter since the device could be damaged.

The invention of the battery -- which could produce a continuous flow of current --

made possible the development of the first electric circuits. Alessandro Volta invented

the first battery, the voltaic pile, in 1800. The very first circuits used a battery and

electrodes immersed in a container of water. The flow of current through the water

produced hydrogen and oxygen.

The first widespread application of electric circuits for practical use was for electric

lighting. Shortly after Thomas Edison invented his incandescent light bulb, he sought

practical applications for it by developing an entire power generation and distribution

system. The first such system in the United States was the Pearl Street Station in

downtown Manhattan. It provided a few square blocks of the city with electric power,

primarily for illumination.

In 1964, Earl Warren in his report outlined the importance of providing personal

protection to high government officials and the protection of the president, vice

president and members of their immediate families, the president-elect, the vice

president-elect, former presidents and their wives, widows of former presidents until

their death or remarriage, children of former presidents until they reach the age of 16,

presidential and vice-presidential candidates of the major parties, and visiting heads of

foreign governments.

One classification of circuits has to do with the nature of the current flow. The earliest

circuits were battery-powered, which made in a steady, constant current that always

flowed in the same direction. This is direct current, or DC. The use of DC continued

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through the time of the first electric power systems. A major problem with the DC

system was that power stations could serve an area of only about a square mile

because of power loss in the wires.

In 1883, engineers proposed harnessing the tremendous hydroelectric power potential

of Niagara Falls to supply the needs of Buffalo, N.Y. Although this power would

ultimately go beyond Buffalo to New York City and even farther, there was an initial

problem with distance. Buffalo was only 16 miles from Niagara Falls, but the idea

was unworkable -- until Nikola Tesla made it possible, as we'll see on the next page.