Socket - this is one of the two parts of the plug connector, installed on the wall with a fixed wiring or a constructive part of the equipment. The second part of the connector plug becomes.
The history of development
With the invention of incandescent bulbs has begun electrification of buildings. Direct current was used in all spheres of life, although it appeared generators. The first magneto patented in 1842 by Stephen Woolrich (UK 9431). Alternator galvanization to be used (coating articles with a thin metallic layer) for the purpose. In the west, in large alternators are known and used since the second half of the XIX century for different purposes. But the engines work exclusively with direct current.
Prior to Nikola Tesla, in 1886, domestic appliances operated by electric power, outstanding constant current. Unlike mechanical alternators special prefix, rectifies alternating current. The first hydroelectric power station (Kregsayd, England) was erected in 1868. She drives a rotor DC dynamos. Use electricity intended for:
- hot water;
- household appliances.
A few years later Belgian Zenobio grams created generator, which has enough energy for industrial applications. This marked the beginning of the active use of electricity. For the first time suppliers have done a great discount on the power consumption of lighting fixtures. That came up with clever consumers:
In household appliances attended only two power wires, no plugs. There was no difference where to connect the equipment. As a result, chasing a discount, people began to attach findings to the cartridge lights (after twisting). And stealing electricity.
The situation quickly became known suppliers. Cancel and lose all the profit is not it even occurred. Instead, in 1883, someone with a catchy name Smith (translation - smith) invented the two-pin socket. By 1885 invention came into use, tools provide steel cord and plug. No one wanted to give up the relatively safe lighting when Edison patented the first incandescent lamp.
The novelty was transferred to public places, the visitors noted that breathing became easier after the gas jets in the room was cooler. Suppliers were given first to get used to the novelty, and when the benefits of electric lighting became apparent - tightened nuts and began to remove the profit. At the same time in the late 80's there is already the first washing machine, trying to automate and washing dishes. Electricity becomes a major way to improve productivity.
Sockets in the XX century
While Edison and Tesla are struggling for ideas, the public craves entertainment. By the beginning of XX century, cream and black do not see themselves without electricity on demand is a proposal. General Electric said plug connectors are an integral part of their own products. All new designs to market:
- 1895. GB189516898 patent describes a coaxial connector for the power lines.
- February 26, 1903 Harvey Hubbell takes a patent on the two-pin plug connector. Describes the socket mounted on the wall. They differed from the European presence of tabs on the ends of the rod contacts. Like the jack (Jack) used in the record.
- Ironically, in 1904 he published patent (US 774,250) to plug into a socket Edison bulb. Some joker remembered how three decades earlier stealing electricity and decided to make such formal methods. Fortunately, sparing tariffs for illumination already canceled.
- Patent US776326 A (1904) scores for the author the right to a splitter with a base in the form of a cap lamp Edison, allowing at the same time to twist the light bulb and attach near appliances. The second variant of the invention provides a tee to the same interface. Instead of bulbs may have include three devices. The bi-pin sockets splitter, such as those that were used in the USSR. The pins reminded Jackie of record.
- There was a nest Chapman. The distinctive feature in the form of steel pins sidelobe resembling ground earthing-pin. Certainly, there was got neutral conductor and phase. And although the current-carrying parts were covered with plastic, security products did not differ.
- Patent US774251 A (1904) is similar to the US 774,250, but the realization of the idea of connecting the appliance to the lampholder different. Inside the socket is screwed into a cylindrical shape. The form of both flat contacts. Today, the model in the home do not meet. Present modifications and tees as in the patent US776326 A, with surface contacts.
- Hubbell picked up and turned contacts 90 degrees to the plane are parallel. By 1915, this was considered the most common form. Later triumph modern European form factor in 1903.
- US three-pin socket with earth appeared in 1911. Catalogs describe products with similar plugs and consumption of 2.5 and 5 amperes. The configuration almost identical products BS 546 (the aging British standard plug connectors household appliances). Common in third world countries, India and South America.
- April 18, 1916, George Knapp of the company Harvey Hubbell receives a patent on a fork, where ground contact slightly longer than the other two. This allows the circuit breakers are guaranteed to turn off the broken equipment, and the person to protect from accidental electric shock. Today, most of the plug-in connections are protecting against accidents.
- Familiar with protective earthing-pin petals invented in 1930 by German engineer Albert Buttner from Laufen, the Bavarian manufacturer electricians. Family group ABL Sursum and today boasts an ancestor. Curiously, the phase fed into the pre-war Germany two contacts, the voltage was 110 with respect to ground on each. Linear Voltage - 220 V. As a result, machines on the network should include bipolar, at least. Sometimes refer to the "Eurosystem", as stated in 1926, but it is not true. Original name modern standard - Shuko (registered trademark, from it. - Protective contact).
- The American version of the 3-pin socket invented by Philip Labre. Of the differences - phase and neutral contacts are parallel to each other, and grounding pin is semicircular and below. The story is that a housewife Labre included fan outlet when the cat suddenly decided to return home through the window. He tipped device at the woman, and the one touching the electrical parts, get an electric shock. The engineer quickly determined that a grounding incident would have been negligible.
Features modern plug connectors
People do not understand why there is a hole in the euro plug with metal contacts lurks there. Rumor has it that it is the fuse. In fact, it is a protective contact earthing-pin version for France. Used in:
- Czech Republic.
- Africa series.
Protective contact longer than others, closes the first ground as a result, eliminating the possibility of accidents and emergencies. Today the world is well known 20 types of plug connectors. For the most part it is a tribute to tradition. Although sometimes place puts strategic reasons.
Appointment ground petals
Side lobes are necessary not only for the earth, but for the correct operation of the input apparatus filters and differential circuit breaker in the home involving TN-S system.
Negative side TN-S
When zero neutral conductors and grounding socket divided by the length, special requirements are imposed on the protection apparatus. For example, in three-phase circuits is prohibited housing grounded without vanishing. Otherwise, in case of accident the entire operating current goes through man. Neutral take away the lion's share of the load, because the land is activated only when the phase imbalance. For a TN-S unacceptable devices comprise three-phase current in the usual manner. And the case of household appliances directly grounded.
For these reasons, the system used in the USSR TN-C-S, where the working and protective earth conductor of the socket at the entrance to the building combined. In this case, the three-phase network of a large current does not go to the person by negligence which undertook a bare current-carrying part of the plant - the potential of the land above the negative pole one of the phases. With the implementation of the system TN-C-S it is possible to use in the same building and single-phase three-phase devices by conventional schemes.
In the West, great attention is paid to protection from interference. For example, the surge protector prevents the personal computer system unit from false inclusion "alarm". Certain motherboards are configured so that the interference received from the food chain, are automatically included. Let's say at night when everyone is asleep. This negative effect in the Russian Federation, according to reports in the forum, mishap happens all the time from ignorance mentioned features of the equipment.
Advantages of the system TN-S
Unlike western art - it is designed to be compatible with a healthy lifestyle. To mention two aspects.
First, the frame ground from an AC outlet. Zero resistance of the ground conductor does not exceed 10 ohms circuit 220 V. This is obviously smaller than the path to the substation where the grounded neutral transformer. And the load on the line less. Consequently, the protection is qualitative, plus noise filtering and shielding. Suffice it to annihilate the microwave oven through the housing socket so that it no longer pose a danger to the radiation point of view in the range of microwave and 50 Hz. A grounding reinforces these positive effects.
Secondly, the noise filtering. Imported equipment is assembled so that the neutral and ground in the instrument are considered fundamentally different branches. Filters are symmetrical. From the neutral conductor interference goes to the ground through a socket, as well as from the phase. Explanation:
- The first part of the filter protects the unit from the incoming voltage and current disturbances. Principle: do not let yourself offense.
- The second part protects the network from the device induced interference. The principle: do no harm.
This is clearly observed in Europe.
Installation of switches and plug sockets
The sockets are put in certainly podrozetnik except overhead models. The usual place setting - 0.8 - 1 meter above the floor. In kindergartens, nurseries and junior high school is allowed to set up, so as not got kids. Overhead sockets are put on the fireproof base thickness of 10 mm when installed on wooden or other similar wing wall. Concrete not install without preamble. Power supplied cable channel, not to Stroebe wall.