The report of the court proceedings includes a comprehensive review of the development of the art in the US prior to 1919, based on evidence presented to the Court. In 1919, Hubbell unsuccessfully tried to prevent other manufacturers from making receptacles and plugs to the dimensions used by Hubbell. It is worth noting that in addition to Hubbell's system, circulated a large variety of different plugs and receptacles, some of them compatible with Hubbell's, some not. 4 and 5, showing a concept for polarized receptacle and plug. The flat blade plug which in subsequent years evolved to become NEMA 1-15 was born. This design was improved once again in 1915, introducing a polarized plug under the U.S. The new design had parallel blades, a more compact design and was easier to manufacture. In 1910, Hubbel worked on improving his popular flat blade design, filled U.S. Patent 774,251 Both these patents were granted in November 1904. Later in 1904, he changed the design to flat blades (a design later incorporated in the NEMA 2 series), filled under the U.S. The same patent had a second design, with a wall attachable receptacle, capable of receiving the same plug, thus being the first socket and plug design patented in the US. The adaptor was screwed into the lightbulb socket, leaving a flat face with two holes to conveniently attach the plug. Patent 774,250, for a lightbulb socket adaptor and plug, also a standalone receptacle. One big disadvantage of screw connectors was that the cord inevitably got twisted after being connected to the receptacle. In the early 1900s, table and floor lamps became more popular, and sockets were mounted on walls for secondary connections. The Edison screw was very successful, and quickly became the first de facto standard for electric connection. Along with his lightbulb, Thomas Edison developed the Edison screw in the early 1880s, for which he received a patent in 1881.
In the early days of electrification, residential use was almost exclusively for illumination, with rooms normally having just a single spot in the center. Main article: History of AC power plugs and sockets
The dimensional standard for electrical connectors is ANSI/NEMA WD-6 and is available from the NEMA website. Other plug and receptacle types are for special purposes or for heavy-duty applications. NEMA 1-15P (two-pole, no ground) and NEMA 5-15P (two-pole with ground pin) plugs are used on common domestic electrical equipment, and NEMA 5-15R is the standard 15-ampere electric receptacle (outlet) found in the United States, and under relevant national standards, in Canada ( CSA C22.2 No. Different combinations of contact blade widths, shapes, orientations, and dimensions create non-interchangeable connectors that are unique for each combination of voltage, electric current carrying capacity, and grounding system. NEMA wiring devices are made in current ratings from 15 to 60 amperes (A), with voltage ratings from 125 to 600 volts (V). NEMA connectors are power plugs and receptacles used for AC mains electricity in North America and other countries that use the standards set by the US National Electrical Manufacturers Association. The NEMA 5-15R device on the far left is most common the two rightmost designs are typically seen in older buildings. All accept a 1-15P plug the two on the left also accept grounded 5-15P plugs the second from the left also accepts 5-20P plugs. Questions? Give us a call or live chat with us using the icon in the bottom right-hand corner of your screen.Main article: AC power plugs and sockets Ungrounded (L) and grounded (R) power plugs Common North American 125-volt receptacles. Acting as industry representatives advocating for legislation and government regulations that serve the industry’s needs.Representing the electrical manufacturer community to the media.Gathering information pertaining to market data.Maintaining a set of core values that member companies adhere to.Providing a forum for development of technical standards.More than 400 companies count themselves as members of NEMA, including General Electric, Philips, Siemens, and ACUPWR. NEMA is the National Electrical Manufacturers Association, a trade association that represents makers of electrical products and medical imaging products manufactured within North America. These plugs are used throughout the U.S., Canada, and Mexico, and include plugs and receptacles that range from domestic size (NEMA 5-15R/P) up to the highest available amp and voltage requirements (NEMA 18-60R/P). ACUPWR's NEMA chart can help you identify which NEMA plug or receptacle you have.
0 kommentar(er)
