interference apparatus

 

прибор для измерения помех
—
[Я.Н.Лугинский, М.С.Фези-Жилинская, Ю.С.Кабиров. Англо-русский словарь по электротехнике и электроэнергетике, Москва, 1999 г.]

Тематики

• электротехника, основные понятия

EN

• interference measuring apparatus

1) Engineering: interference measuring apparatus, interference meter

2) GOST: noise meter (ГОСТ 30372-95/ГОСТ Р 50397-92)

SUBJECT AREA: Electricity, Electronics and information technology, Telecommunications

[br]

[br]

[br]

After obtaining degrees from the universities of Marburg and Berlin (PhD) and spending a short time as Headmaster of the Thomas School in Berlin, Braun successively held professorships in theoretical physics at the universities of Marburg (1876), Strasbourg (1880) and Karlsruhe (1883) before becoming Professor of Experimental Physics at Tübingen in 1885 and Director and Professor of Physics at Strasbourg in 1895.

During this time he devised experimental apparatus to determine the dielectric constant of rock salt and developed the Braun high-tension electrometer. He also discovered that certain mineral sulphide crystals would only conduct electricity in one direction, a rectification effect that made it possible to detect and demodulate radio signals in a more reliable manner than was possible with the coherer. Primarily, however, he was concerned with improving Marconi's radio transmitter to increase its broadcasting range. By using a transmitter circuit comprising a capacitor and a spark-gap, coupled to an aerial without a spark-gap, he was able to obtain much greater oscillatory currents in the latter, and by tuning the transmitter so that the oscillations occupied only a narrow frequency band he reduced the interference with other transmitters. Other achievements include the development of a directional aerial and the first practical wavemeter, and the measurement in Strasbourg of the strength of radio waves received from the Eiffel Tower transmitter in Paris. For all this work he subsequently shared with Marconi the 1909 Nobel Prize for Physics.

Around 1895 he carried out experiments using a torsion balance in order to measure the universal gravitational constant, g, but the work for which he is probably best known is the addition of deflecting plates and a fluorescent screen to the Crooke's tube in 1897 in order to study the characteristics of high-frequency currents. The oscilloscope, as it was called, was not only the basis of a now widely used and highly versatile test instrument but was the forerunner of the cathode ray tube, or CRT, used for the display of radar and television images.

At the beginning of the First World War, while in New York to testify in a patent suit, he was trapped by the entry of the USA into the war and remained in Brooklyn with his son until his death.

[br]

SUBJECT AREA: Textiles

[br]

[br]

[br]

Heathcote was the son of a small farmer who became blind, obliging the family to move to Long Whatton, near Loughborough, c.1790. He was apprenticed to W.Shepherd, a hosiery-machine maker, and became a frame-smith in the hosiery industry. He moved to Nottingham where he entered the employment of an excellent machine maker named Elliott. He later joined William Caldwell of Hathern, whose daughter he had married. The lace-making apparatus they patented jointly in 1804 had already been anticipated, so Heathcote turned to the problem of making pillow lace, a cottage industry in which women made lace by arranging pins stuck in a pillow in the correct pattern and winding around them thread contained on thin bobbins. He began by analysing the complicated hand-woven lace into simple warp and weft threads and found he could dispense with half the bobbins. The first machine he developed and patented, in 1808, made narrow lace an inch or so wide, but the following year he made much broader lace on an improved version. In his second patent, in 1809, he could make a type of net curtain, Brussels lace, without patterns. His machine made bobbin-net by the use of thin brass discs, between which the thread was wound. As they passed through the warp threads, which were arranged vertically, the warp threads were moved to each side in turn, so as to twist the bobbin threads round the warp threads. The bobbins were in two rows to save space, and jogged on carriages in grooves along a bar running the length of the machine. As the strength of this fabric depended upon bringing the bobbin threads diagonally across, in addition to the forward movement, the machine had to provide for a sideways movement of each bobbin every time the lengthwise course was completed. A high standard of accuracy in manufacture was essential for success. Called the "Old Loughborough", it was acknowledged to be the most complicated machine so far produced. In partnership with a man named Charles Lacy, who supplied the necessary capital, a factory was established at Loughborough that proved highly successful; however, their fifty-five frames were destroyed by Luddites in 1816. Heathcote was awarded damages of £10,000 by the county of Nottingham on the condition it was spent locally, but to avoid further interference he decided to transfer not only his machines but his entire workforce elsewhere and refused the money. In a disused woollen factory at Tiverton in Devonshire, powered by the waters of the river Exe, he built 300 frames of greater width and speed. By continually making inventions and improvements until he retired in 1843, his business flourished and he amassed a large fortune. He patented one machine for silk cocoon-reeling and another for plaiting or braiding. In 1825 he brought out two patents for the mechanical ornamentation or figuring of lace. He acquired a sound knowledge of French prior to opening a steam-powered lace factory in France. The factory proved to be a successful venture that lasted many years. In 1832 he patented a monstrous steam plough that is reputed to have cost him over £12,000 and was claimed to be the best in its day. One of its stated aims was "improved methods of draining land", which he hoped would develop agriculture in Ireland. A cable was used to haul the implement across the land. From 1832 to 1859, Heathcote represented Tiverton in Parliament and, among other benefactions, he built a school for his adopted town.

[br]