Karl Ferdinand Braun
Ferdinand Braun
Born	June 6, 1850(1850-06-06) Fulda, Hesse-Kassel, Germany
Died	April 20, 1918 (aged 67) Brooklyn, New York
Residence	Germany
Nationality	German
Field	Inventor and physicist
Institutions	University of Strasbourg
Alma mater	University of Marburg University of Berlin
Academic advisor	August Kundt
Notable students	Leonid Isaakovich Mandelshtam
Known for	CRT, Cat's whisker diode
Notable prizes	Nobel Prize in Physics (1909)

Karl Ferdinand Braun (6 June 1850 in Fulda, Germany – 20 April 1918 in New York City, U.S.) was a German inventor, physicist and Nobel Prize laureate. Image File history File linksMetadata Ferdinand_Braun. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... For the game, see: 1850 (board game) 1850 (MDCCCL) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Sunday [1] of the 12-day-slower Julian calendar). ... , Fulda (IPA: ) is a city in Hessen, Germany; it is located on the Fulda River and is the administrative seat of the Fulda district (Kreis). ... Hesse-Kassel (Hessen-Kassel in German) was a German principality that came into existence when the Landgraviate of Hesse was divided in 1568 upon the death of Landgrave Philip I of Hesse. ... is the 110th day of the year (111th in leap years) in the Gregorian calendar. ... 1918 (MCMXVIII) was a common year starting on Tuesday of the Gregorian calendar (see link for calendar) or a common year starting on Wednesday of the Julian calendar. ... This article is about the borough of New York City. ... This article is about the state. ... For other uses, see Inventor (disambiguation). ... Not to be confused with physician, a person who practices medicine. ... The University Palace in Strasbourg, and a monument to one of the universitys students, Johann Wolfgang Goethe The University of Strasbourg in Strasbourg, Alsace, France, is divided into three separate institutions. ... University of Marburg - Department of Social Sciences and University library The old university The University of Marburg (German: Philipps-Universität Marburg Philips University, Marburg), was founded in 1527 by Landgrave Philipp I of Hesse (usually called the Magnanimous, although the updated meaning haughty is sometimes given) as the... There is no institution called the University of Berlin, but there are four universities in Berlin, Germany: Humboldt University of Berlin (Humboldt-Universität zu Berlin) Technical University of Berlin (Technische Universität Berlin) Free University of Berlin (Freie Universität Berlin) Berlin University of the Arts (Universität der... August Adolf Eduard Eberhard Kundt (18 November 1839 – 21 May 1894) was a German physicist. ... Leonid Isaakovich Mandelshtam (Леонид Исаакович Мандельштам, last name more often spelled as Mandelstam) (May 4, 1879 - November 27, 1944) was a Russian/Soviet physicist of Jewish background. ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ... A Cats Whisker is the tiny wire that connects to the detector in a crystal radio. ... Image File history File links No higher resolution available. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... For the game, see: 1850 (board game) 1850 (MDCCCL) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Sunday [1] of the 12-day-slower Julian calendar). ... , Fulda (IPA: ) is a city in Hessen, Germany; it is located on the Fulda River and is the administrative seat of the Fulda district (Kreis). ... is the 110th day of the year (111th in leap years) in the Gregorian calendar. ... 1918 (MCMXVIII) was a common year starting on Tuesday of the Gregorian calendar (see link for calendar) or a common year starting on Wednesday of the Julian calendar. ... New York, New York and NYC redirect here. ... For other uses of terms redirecting here, see US (disambiguation), USA (disambiguation), and United States (disambiguation) Motto In God We Trust(since 1956) (From Many, One; Latin, traditional) Anthem The Star-Spangled Banner Capital Washington, D.C. Largest city New York City National language English (de facto)1 Demonym American... For other uses, see Inventor (disambiguation). ... Not to be confused with physician, a person who practices medicine. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... The word laureate or laureated has came in English to signify eminent, or associated with glory, literary or military. ...

Biography

Braun was educated at the University of Marburg and received a Ph.D from the University of Berlin in 1872. In 1874 he discovered that a point-contact semiconductor rectifies alternating current. He became director of the Physical Institute and professor of physics at the University of Strasbourg in 1895. University of Marburg - Department of Social Sciences and University library The old university The University of Marburg (German: Philipps-Universität Marburg Philips University, Marburg), was founded in 1527 by Landgrave Philipp I of Hesse (usually called the Magnanimous, although the updated meaning haughty is sometimes given) as the... There is no institution called the University of Berlin, but there are four universities in Berlin, Germany: Humboldt University of Berlin (Humboldt-Universität zu Berlin) Technical University of Berlin (Technische Universität Berlin) Free University of Berlin (Freie Universität Berlin) Berlin University of the Arts (Universität der... Year 1872 (MDCCCLXXII) was a leap year starting on Monday (link will display the full calendar) of the Gregorian Calendar (or a leap year starting on Saturday of the 12-day slower Julian calendar). ... Year 1874 (MDCCCLXXIV) was a common year starting on Thursday (link with display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ... A semiconductor is a solid whose electrical conductivity is in between that of a conductor and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... AC, half-wave and full wave rectified signals A rectifier is an electrical device, comprising one or more semiconductive devices (such as diodes) or vacuum tubes arranged for converting alternating current to direct current. ... City lights viewed in a motion blurred exposure. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... The University Palace in Strasbourg, and a monument to one of the universitys students, Johann Wolfgang Goethe The University of Strasbourg in Strasbourg, Alsace, France, is divided into three separate institutions. ... Year 1895 (MDCCCXCV) was a common year starting on Tuesday (link will display full calendar) of the Gregorian calendar (or a common year starting on Sunday of the 12-day-slower Julian calendar). ...

In 1897 he built the first cathode-ray tube oscilloscope. CRT technology is to this day used by most television sets and computer monitors. The CRT is still called the "Braun tube" (Braunsche Röhre) in German-speaking countries (and in Japan: Buraun-kan). 1897 (MDCCCXCVII) was a common year starting on Friday (see link for calendar). ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ... Illustration showing the interior of a cathode-ray tube for use in an oscilloscope. ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ...

During the development of radio, he also worked on wireless telegraphy. Around 1898, he invented a crystal diode rectifier or Cat's whisker diode. Guglielmo Marconi used Braun's patents (among others). Braun's British patent on tuning was used by Marconi in many of his tuning patents. Marconi would later admit to Braun himself that he had "borrowed" portions of Braun's work. In 1909 Braun shared the Nobel Prize for physics with Marconi for "contributions to the development of wireless telegraphy." For the controversy about who invented radio, see Invention of radio. ... For the use of the term in networking, see Wireless networking. ... Telegraph and Telegram redirect here. ... Closeup of the image below, showing the square shaped semiconductor crystal various semiconductor diodes, below a bridge rectifier Structure of a vacuum tube diode In electronics, a diode is a two-terminal component, almost always one that has electrical properties which vary depending on the direction of flow of charge... A Cats Whisker is the tiny wire that connects to the detector in a crystal radio. ... For the inventor of radio,Marconi see the competing claims in history of radio and the invention of radio. ... Year 1909 (MCMIX) was a common year starting on Friday (link will display full calendar) of the Gregorian calendar (or a common year starting on Thursday of the 13-day-slower Julian calendar). ... The Nobel Prize (Swedish: ) was established in Alfred Nobels will in 1895, and it was first awarded in Physics, Chemistry, Physiology or Medicine, Literature, and Peace in 1901. ...

Braun went to the United States at the beginning of World War I to help defend the German wireless station at Sayville, N.Y. (on Long Island) against attacks by the British controlled Marconi Corporation. (At this time the U.S. had not yet entered the war). Braun died in his house in Brooklyn (New York City) before the war ended in 1918. “The Great War ” redirects here. ... Sayville is the name of a hamlet and of a census-designated place located in Suffolk County on Long Island. ... This article is about the island in New York State. ... The Marconi Corporation plc is a radio, telecommunication, and internet equipment manufacturing company, formerly known as The General Electric Company and Marconi plc Marconi Corporation should not be confused with the Marconi Company founded by Guglielmo Marconi. ... This article is about the borough of New York City. ... New York, New York and NYC redirect here. ...

References

1. K.F. Braun: "On the current conduction in metal sulphides (title tranlated from German into English)", Ann. Phys. Chem., 153 (1874), 556. (In German) An English translation can be found in "Semiconductor Devices: Pioneering Papers", edited by S.M. Sze, World Scientific, Singapore, 1991, pp. 377-380.

2. Keller, Peter A.: The cathode-ray tube: technology, history, and applications. New York: Palisades Press, 1991. ISBN 0-9631559-0-3.

3. Keller, Peter A.: "The 100th Anniversary of the Cathode-Ray Tube," Information Display, Vol. 13, No. 10, 1997, pp. 28-32.

See also

• Radio: History of radio, Invention of radio
• People: Edouard Branly

For the controversy about who invented radio, see Invention of radio. ... // Within the timeline of radio, many people were involved in the invention of radio transmission of information as we know it today. ... Eugène Édouard Désiré Branly (23 October 1844 - 24 March 1940) was a French physicist. ...

External articles and references

Patent

• U.S. Patent 0,750,429 
• U.S. Patent 0,763,345 

Other

• "Ferdinand Braun – Biography". Nobel Lectures. Physics 1901-1921, Elsevier Publishing Company, Amsterdam, 1967.
• Naughton, Russell, "Karl Ferdinand Braun, Dr : 1850 - 1918".
• "Karl Ferdinand Braun ". Biographies of Famous Electrochemists and Physicists Contributed to Understanding of Electricity.
• Rybak, James P., "Forgotten" Pioneers of Wireless; Part 5 - Karl Ferdinand Braun".
• "Karl Ferdinand Braun, 1850-1918". (German) (English translation)
• The Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik Berlin, Germany