A form of eletricity where the electrical potential (voltage) does not vary, and so the electrons travel in only one direction along the conductor. Found in batteries and other chemical-eletric devices, and where ac->dc converters are used. Disadvantage: transformers are much more difficult to create with DC.

Direct current was originally used in power lines in the United States. Due to the fact that Direct Current was used and not Alternating Current, the power lines glowed red and got very hot. This meant that being as power was being lost to heat up the wires, a generator was needed every few blocks to keep the current going and to make it reach its destinations.

Although alternating current was available and a known fact about how it worked, direct current was a preference due to the fact that people were scared of it because they knew that it was dangerous due to its high voltages. Alternating current was then introduced and people protested because of its dangers. The scientists developing the power lines did a public demonstration to prove the safety of A.C. They got a power cable and got a 'test man', he held onto the wires and said that it 'wasn't too bad'. People then accepted the new cables and lived on with the new alternating current.
What the scientists had done was to use a very high frequency and low current on the wire. This induced a small pulse like on a fields perimiter fence. Rather than the high voltages which are used in power lines, which were sure to fry the man.

abbreviation DC, flow of electric charge that does not change direction. Direct Current is produced by batteries, fuel cells, rectifiers, and generators with commutators. Direct current was supplanted by alternating current (AC) for common commercial power in the late 1880s because it was then uneconomical to transform it to the high voltages needed for long-distance transmission. Techniques that were developed in the 1960s overcame this obstacle, and direct current is now transmitted over very long distances, even though it must ordinarily be converted to alternating current for final distribution. For some uses, such as electroplating, direct current is essential.

Direct current. (Elec.)

(a)

A current flowing in one direction only; -- distinguished from alternating current. When steady and not pulsating a direct current is often called a continuous current.

(b)

A direct induced current, or momentary current of the same direction as the inducing current, produced by stopping or removing the latter; also, a similar current produced by removal of a magnet.

 

© Webster 1913

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