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About this Article
Written by: Robin Hartman
Written on: June 19th, 2008
Tags: electrical engineering, lifestyle
Thumbnail by: AndrewBuck/Wikimedia Commons
About the Author
A junior majoring in Biomedical Engineering in Spring 2008, Robin was perplexed by the number of different types of electrical outlets she saw during her travels around Europe. She believed that there must be a way to standardize the outlet, though was unsure the international electrical outlet market would agree.
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Volume X Issue II > A Powerful History: The Modern Electrical Outlet
The electrical outlet is a modern convenience that we often take for granted - until it becomes an inconvenience. When traveling abroad, you must purchase adapters, converters and transformers with no guarantee that these will fit into your hotel room outlet. There have been a number of developments to make the outlet a safer, more user-friendly innovation relative to its origins of do-it-yourself wiring and light-bulb socket plugs. Its history is intertwined with that of modern household lighting and electricity. There has been little recent development in the electrical outlet, but there seems to be broadband internet in its future.

Introduction

When traveling abroad, you buy at least five different types of electrical adapters and transformers yet somehow still end up in a hotel where your cell phone charger will not plug into the outlet. Or, perhaps you have attempted to plug your hair dryer into the bathroom outlet using a simple adapter and have blown a fuse. Why do we need all these adapters and transformers while traveling? The simple answer is that individual regions independently chose to develop their own technology and no standard was set early on (Fig. 1 shows the US standard outlet). The electrical outlet is an invention created purely for convenience, so we tend to forget about its elegant engineering until it becomes an inconvenience. The engineering of the outlet has evolved: we have gone from about ten different frequencies to just two in the world, and we have two standard voltages as well. But where exactly did household electricity begin and how did it bring about one of the most over-looked, yet important, inventions of the modern household?
AndrewBuck/Wikimedia​ Commons
Figure 1: A standard electrical outlet

The History of Electricity

There was considerable delay between the discovery of electric power and the capacity to harness this power for work; this transition is recorded in a series of biographies from Benjamin Franklin to Philip F. Labre. However, Ben Franklin did not "discover" electricity as so many of us are led to believe in elementary school history classes. In fact, the Greeks made early observations of magnetism and even wondered about the origins of lightning [1]. Lightning, as we now know, is caused by a buildup of electrons in thunderclouds when particles in the clouds rub together. As the electrons build up, they must discharge to a positively charged or neutral surface, usually another cloud or the ground.
In the mid 1600's, Otto Von Guericke created the first static electricity generator from a ball of sulfur [2]. This sulfur ball led to a century's worth of investigation in static electricity. With his famous kite experiment, Ben Franklin proved that lightning was, in fact, a form of electricity : the same kind of "electric fire" was ejected from the kite as was produced by experiments similar to the one created by Von Guericke's sulfur ball [3]. From this and other experiments, Franklin was able to develop his Electric Fluid Model.
Franklin's Model described electricity as a fluid and introduced the concept of "conservation" of "electric fluid" [4]. Within a system, however, charge can collect on one object and deplete on another, inducing "positive" and "negative charge, respectively. Fluid in this case does not mean a liquid, but simply something consisting of freely-flowing particles. Franklin also understood the concepts of "opposites attract" and "likes repel," because he noted that objects with a deficit of electric fluid were attracted to objects with an excess of electric fluid, and that two objects in the same state - if both had a deficit or both had an excess - repelled one another. This fluid could also flow from areas of excess to areas of deficit. His "fluid," as we now realize, actually describes individual electric charges we called electrons and protons [5].
One of the earliest controversies associated with modern electricity came as a result of Luigi Galvani's experiments with frog muscles in the late 1700's. After observing muscular twitches after he accidentally touched his scalpel to a frog's leg muscle, he began experimenting with different metals to see if he could reproduce the same twitch [6]. He found that if a bimetallic arc (essentially a circuit with two metals connected to one another and the frog muscle or nerve, Figure 1) was made, no source of electricity was necessary to make the leg twitch. Galvani reasoned that since there was no outside source of electricity, the source was "animal electricity" in the leg itself, claiming it to be the life force of all animals.
However, about a decade later, Alessandro Volta emerged with a new interpretation: his theory stated that the twitch was caused by contact between the two different conducting metals Galvani had been using. In order to prove that it was the different metals and not the frog leg causing the movement, Volta removed the frog from the experiment and enhanced Galvani's design, creating the earliest voltaic cell. It consisted of a piece of cardboard soaked in salt water, with pieces of copper and zinc placed within it: this caused a chemical transfer of charges between the metals, inducing a current or electron flow [7]. The unit "Volt" was named after Volta and it represents the electric potential between two points.
From this new electric source, Michael Faraday was inspired to develop the electric generator, which employed a changing magnetic field to produce a current. This was the first instance of using mechanical energy to create electricity, a fundamental element of future dams. This generator was used to provide electricity to the household.