Nowadays almost everything that we have at home depends on electricity. Computes, fans, cell-phones. All this was created by human mind due to invention of electricity. Now I’d like to tell about a provider between these two worlds – electricity and devices – it is a well-known electrical socket.
At first a few words about the first years of electricity. When electricity was first introduced into the household, it was primarily used for lighting. At that time, many electricity companies operated a split-tariff system where the cost of electricity for lighting was lower than that for other purposes. This led to portable appliances (such as vacuum cleaners, electric fans, and hair driers) being connected to the light fitting.
However, as electricity became a common method of lighting houses and operating labor-saving appliances, a safe means of connection to the electric system other than using a light socket was needed. The original two pin electrical plug and socket were invented by Harvey Hubbell and patented in 1904. Other manufacturers adopted the Hubbell pattern and by 1915 they were widespread, although in the 1920s and even later, household and light commercial equipment was still powered through cables connected with Edison screw-base adapters to lamp holders.
The three-prong plug was invented by Philip F. Labre, while he was attending the Milwaukee School of Engineering (MSOE). As many scientists he found an inspiration in his environment. It is said that his landlady had a cat which would knock over her fan when it came in the window. When she plugged the fan back in, she would get an electric shock. Labre figured out that if the plug were grounded, the electricity would go to earth through the plug rather than through his landlady. He applied for and was issued a patent for grounding receptacle and plug on June 5, 1928. As the need for safer installations became apparent, earthed three-contact systems were made mandatory in most industrial countries.
During the first fifty years of commercial use of electric power, standards developed rapidly based on growing experience. Technical, safety, and economic factors influenced the development of all wiring devices and numerous varieties were invented. Gradually the desire for trade eliminated some standards that had been used only in a few countries. Former colonies may retain the standards of the colonizing country, occasionally—as with the UK and a number of its former colonies — after the colonizing country has changed its standard. Sometimes offshore industrial plants or overseas military bases use the wiring practices of their controlling country instead of the surrounding region. Hotels and airports may maintain receptacles of foreign standards for the convenience of travelers. Some countries have multiple voltages, frequencies and plug designs in use, which can create inconvenience and safety hazards.
Design features and aspects of plugs and sockets have evolved to reduce the risk of electric shock and equipment damage.
In recent years many countries have settled on one of a few de facto standards, which became formalized as official national standards, although there remain older installations of obsolete wiring in most countries. Some buildings have wiring that has been in use for almost a century and which pre-dates all modern standards.
Many manufacturers of electrical devices like personal computers have adopted the practice of putting a single world-standard IEC connector on the device, and supplying for each country a power cord equipped with a standard IEC connector on one end and a national power plug at the other. The device itself is designed to adapt to a wide range of voltage and frequency standards. This has the practical benefit of reducing the amount of testing required for approval, and reduces the number of different product variations that must be produced to serve world markets.
If we take the world-wide picture the standards for outlets are not the same. There are two basic standards for voltage and frequency in the world. One is the North American standard of 110-120 volts and the other is the European standard of 220-240 volts. Countries on other continents have adopted one of these two voltage standards, although some countries use variations or a mixture of standards. Electrical plugs and their sockets differ by country in shape, size and type of connectors. The type used in each country is set by national standards legislation.
Special purpose sockets may be found in industrial, commercial or institutional buildings. These may be merely labeled or colored, or may have different arrangements of pins or keying provisions. Some special-purpose systems are incompatible with general-purpose lighting and appliances. Examples of systems using special purpose sockets include for example theatrical lighting or isolated power for medical instruments.
Depending on the nature of the system, special-purpose sockets may just identify a reserved use of a system (for example, computer power) or may be physically incompatible with utility sockets to prevent use of unintended equipment which could create electrical noise or other problems for the intended equipment on the line.
Sockets that take a variety of plug types can be found in various countries where market size or local market conditions make a specific plug standard impractical to implement. These socket accept plugs fitting various European, Asian and North American standards. Since many plug standards are also associated with corresponding voltages, multi-standard sockets do not safeguard against devices being damaged by the wrong voltage. This forces users to be aware of the voltage requirements of their appliances as well as the prevailing local voltage. Devices designed to adapt automatically to whatever voltage and frequency is supplied, and which don't require earthing, are generally safe to use with these sockets.
A few words about sockets in other spheres:
In biology:
- Eye socket, a region in the skull where the eyes are positioned
- Tooth socket, a cavity containing a tooth, in those bones that bear teeth
- Dry socket, a painful opening as a result of the blood not clotting after a tooth is pulled
In computing:
- Internet socket, an end-point in the IP networking protocol
- CPU socket, the connector on a computer's motherboard for the CPU
- Unix domain socket, an end-point in local inter-process communication
- An end-point of a bi-directional communication link in the Berkeley sockets API.
In entertainment:
- Socket (video game), a video game created by Vic Tokai on the Sega Genesis
- Socket (film), a gay-themed science-fiction indie film
The final Curious © phrase:
“If it weren’t for electricity we’d all be watching television by candlelight”
(George Gobal)
