Ernst Fredrik Werner Alexanderson

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Ernst Fredrik Werner Alexanderson (born January 25, 1878 in Uppsala , † May 14, 1975 in Schenectady , New York ) was a Swedish-American electrical engineer and inventor.

By further developing the first machine transmitters at General Electric (GE) into the "Alexanderson Alternator" named after him, he made a decisive advance in radio technology and enabled Reginald Fessenden to broadcast the first radio broadcast in 1906 . In addition to making numerous contributions to the development of radio , from the late 1920s to the 1950s he pioneered the development of wireless image transmission from fax to color television at the Radio Corporation of America (RCA) . His other inventions include the electromotive amplifier produced by GE under the brand name "Amplidyne" , which was mainly used to control anti-aircraft guns during the Second World War .

Alexanderson alternator, 200 kW version from 1918, for the United States Navy in New Brunswick

life and career

Training and career entry

Alexanderson was the son of Aron Martin Alexanderson (1841–1930), a professor of classical languages ​​at Uppsala University, and his wife Amelie Charlotta Margareta b. Pagan tribe. Following his early interest, he studied electrical and mechanical engineering at Lund University and Stockholm University of Technology . After completing his studies, Alexanderson did his doctorate for about a year with Adolf Slaby at the Technical University of Charlottenburg .

During his time in Berlin, Alexanderson read the book Theory and calculation of alternating current phenomena by Charles P. Steinmetz and was so enthusiastic about it that in 1901, after completing his doctorate, he decided to emigrate to the United States and work with Steinmetz in Schenectady to apply for a job. Shortly after arriving in the States, Alexanderson first visited Thomas Alva Edison's research facility in Menlo Park. However, he got the impression that after the great days of unrestricted research an autocratic system had taken hold there and so he withdrew his application to the Edison Company .

Alexanderson initially took a position as a draftsman at C&C Electrical Company in New Jersey , but continued to seek employment with large companies, particularly Westinghouse and General Electric (GE). In December 1901 he met with Steinmetz and his assistant Ernst Julius Berg . Berg had also immigrated from Sweden about eight years earlier. On the recommendation of Steinmetz, General Electric signed Alexanderson as a draftsman from February 1902. He was also allowed to attend various advanced training courses before he was promoted to engineer in 1904. His first patent idea in October 1902 related to a relay to protect against short circuits in production. As a result, GE was able to dispense with the protection and measuring devices previously required between the workstations and thus saved a lot of money. Sources report that Alexanderson was well aware of his worth and was very ambitious. He was bored with his work as a draftsman and very dissatisfied with his salary. Whenever the opportunity arose, he tried to improve his career or to negotiate a raise. On the way to the second patent, this time to improve an alternating current motor, Steinmetz recognized a design problem upon inspection. GE immediately stopped all preparations for the patent application. When Alexanderson had found a solution to the problem, he initially remained silent about his employer and tried to make more profit for himself by selling it to another company.

Alexanderson alternator

During this time, General Electric worked on behalf of Reginald Fessenden on the construction of a long-wave transmitter that was to be many times stronger than any previously existing. According to the state of the art at that time, a machine transmitter or alternator with a high-frequency generator or dynamo as the core. Poles arranged on a metal disk, which was driven at high speed by a motor, generated an alternating voltage, which was then fed directly into an antenna circuit. Keeping the forces occurring in the large and heavy machines under control even at extremely high speeds posed a number of challenges for the engineers. Steinmetz delivered a first version in 1903 with which a carrier frequency of 10 kHz could be achieved. However, it turned out to be too weak in Fessenden's radio experiments. Alexanderson was ultimately commissioned to design a faster and more powerful successor. After two years of working on several models, Alexanderson was able to present his improved alternator for carrier frequencies up to 50 kHz in August 1906, which was then installed in Fessenden's radio station in Brant Rock , Massachusetts . With this type of transmitter, later referred to as the Alexanderson Alternator, Fessenden succeeded in broadcasting the world's first radio program at 9 a.m. on Christmas Eve of the same year. He had asked customers of the wireless telegraphy service of the National Electric Signaling Company (NASCO), the company that financed Fessenden's work, to turn on their receivers at the appropriate time . Those who followed his calls, listened to their devices, as Fessenden played to keep them entertained violin, a recording of the known as "Largo" classical piece of music by Handel from an Edison - phonograph let out and connected with Christmas greetings from the Bible read. According to Fessenden, another broadcast for the New Year is said to have been received by United Fruit Company ships in the Caribbean .

From 1907 Alexanderson also supported AT&T in the construction of transmission systems and was able to increase the speed of its generators to around 20,000 revolutions per minute for carrier frequencies of 100 kHz by 1908. As a by-product, on the way to this increase, he enriched engineering with an empirical formula for the air friction loss of rotating disks. Reliable transatlantic radio communication was possible from 1911. In 1917 Alexanderson built a 200 kW machine for the United States Navy in New Brunswick , New Jersey . For the start of operation of this Alexanderson alternator on October 20, 1918, President Woodrow Wilson sent an ultimatum to the German Reich, which ended the First World War . Only about four years earlier, the German emperor had exchanged telegraphic greetings between the test station in Tuckerton , New Jersey and the overseas broadcaster Eilvese via the Goldschmidt alternator of the German high-frequency machine stock company for wireless telegraphy (HOMAG) .

After the end of the First World War , the British-controlled Marconi's Wireless Telegraph Company resumed their attempt, which had already begun in 1915, to negotiate with GE over the acquisition of exclusive rights to the Alexanderson alternator. The US government feared it could lose the key technology to a foreign military. As a result, the Radio Corporation of America (RCA) was founded, with which the reorganized American Marconi subsidiary American Marconi Wireless Corporation was merged. General Electric received a controlling majority of the shares in the new company , which brought in its radio and radio technology and Alexanderson as chief engineer. Between 1919 and 1924, Alexanderson split his working hours between GE and RCA. In addition to his work in his laboratory in Schenectady, he went on numerous business trips to personally supervise the construction of radio stations on Long Island and Hawaii , in California , England, Poland and Sweden. When the invention of the electron tube enabled the construction of transmitters with higher frequencies and better transmission power, the machine transmitters quickly lost their importance. The last transmitter of this kind that is still functional today belongs to the Swedish long-wave transmitter Grimeton and is located near Varberg . It is considered a prime example of early broadcast technology and has been on the UNESCO list since 2004 as a World Heritage Site .

TV technology and other inventions

On November 29, 1924, Richard H. Ranger , an engineer at RCA, managed the first wireless fax transmission of a photograph across the Atlantic. He sent a picture of the then President Calvin Coolidge to London. Not long before that, on June 5 of the same year, Alexanderson had successfully transmitted a handwritten note wirelessly to his father in Sweden. In the following years, Alexanderson concentrated increasingly on improving the technology for wireless image transmission. He recognized early on a possibility of developing a method for the transmission of moving images and made a decisive contribution to the history of television . In 1927 he achieved a first transmission using the Nipkow disk developed by Paul Nipkow and a high-frequency neon lamp. He received the signal sent from his office at his home at 1132 Adams Road, Schenectady. While he shares the glory for the invention of television with numerous other researchers who have also made decisive contributions, some of which have been followed with greater public attention, he undisputedly went down in history as the first television viewer with home reception. He publicly demonstrated an improved successor model in the Proctor's Theater in Schenectady and in 1928 sent experimental TV images with his employees with increasing reach.

As part of a telecommunications reorganization in the United States in the late 1920s, the United States Department of Justice brought antitrust lawsuits against AT&T , GE, and Westinghouse. In a settlement in 1932, the companies undertook to give up their stake in RCA. For a transition period of two and a half years, they also had to forego competing with her in the area of ​​radio and radio patents transferred to RCA. Alexanderson turned to David Sarnoff , president of the RCA since 1930, on several occasions for assistance in further funding TV research at GE. But his efforts were unsuccessful. Sarnoff relied on Vladimir Zworykin and Alexanderson had to temporarily stop his work in this area.

Another of his inventions was an electromotive amplifier produced by GE under the brand name “Amplidyne”, which was initially used for automation in production, but during the Second World War it was mainly used to control anti-aircraft guns. In addition, Alexanderson received patents on technical improvements for setting the reception frequency in radios, antenna technology, but also ship propulsion systems, electric motors and electric railways.

Alexanderson remained active well into old age and worked for GE until 1948. Until 1952 he worked as a consultant to the Radio Corporation of America (RCA) on the development of color television.

Private life

One year after he was naturalized in the United States in 1908 , Alexanderson married his first wife Edith B. Lewin (* 1880) on February 20, 1909. She gave birth to daughter Edith in the third year of marriage, but then died on April 26, 1912.

On March 30, 1914, Alexanderson entered into another marriage with Gertrude Robart (* 1882), from which the two daughters Amelie and Gertrude and his son Verner emerged. In 1923, at the age of six, Verner was kidnapped. Alexanderson distributed a description of the person on the GE station in Schenectady. The child was found six days later in a fishing camp on the Indian River in New York State . The kidnappers were later caught and the main perpetrator was sentenced to ten years in prison. About nine years later, about the kidnapping of the Lindbergh baby , Alexanderson's wife wrote to Anne Morrow Lindbergh not to despair and not to lose hope of getting her baby back. Alexanderson's second wife also died in early 1948.

Since the 1930s he developed an increasing love for sailing on Lake George . He owned several boats, was a founding member of the Lake George Yacht Club and also sailed in the Caribbean to the West Indies . At that time, however, his hearing began to deteriorate, so that he later had to rely on a hearing aid. In old age "Alex", as he was called by friends and acquaintances, was practically deaf. It was later reported regretfully from those around him that his clumsy use of the hearing aid made a conversation with him even more difficult.

In June 1949, at the age of 71, he married Thyra Oxehufwud. He lived with her, his third wife, who also had three children from a previous marriage, for 26 years until he died on May 14, 1975 at the age of 97.

Work and awards

A total of 344 patents bear his name, the last of which was registered with the US Patent Office in 1973 when he was 94 years old. He was President of the American Institute of Electrical Engineers , a member of the Royal Swedish Academy of Sciences and the Royal Swedish Academy of Engineering . He also received numerous honorary doctorates and medals:

literature

  • Curt Rint (ed.): Handbook for high frequency and electrical technicians. V. Band. Specialized dictionary . Berlin: Verlag für Radion-Foto-Kinotechnik, 1967, p. 795
  • Kurt Jäger (Ed.): Lexikon der Elektrotechniker , VDE-Verlag, Berlin, 1996, ISBN 3-8007-2120-1 , p. 16 f.
  • James E. Brittain: Alexanderson: Pioneer in American Electrical Engineering Johns Hopkins University Press, 1992, ISBN 978-0-8018-4228-3

Web links

Individual evidence

  1. ↑ Biography of Ernst Fredrik Werner Alexanderson (offline) ( Memento from December 18, 2006 in the Internet Archive )
  2. ↑ a b c d Kurt Jäger (Ed.): Lexikon der Elektrotechniker , VDE-Verlag, Berlin, 1996, ISBN 3-8007-2120-1 , p. 17
  3. ↑ a b c d e f Ernst F. Alexanderson . The accomplishments and life of EF Alexanderson, 1878-1975. In: Engineering Hall of Fame of the Edison Tech Center , accessed on April 17, 2018
  4. ↑ Reginald Aubrey Fessenden . In: Encyclopædia Britannica , accessed April 19, 2018
  5. ↑ a b Albin Krebs: Dr. Ernst Alexanderson, Radio Pioneer, Dies at 97 . Obituary in New York Times , May 15, 1975, retrieved April 18, 2018
  6. ^ Television . In: Resources of the Edison Tech Center , accessed April 17, 2018
  7. ↑ Mary Cirincione: GE 125th Anniversary: Hidden history of GE Realty Plot . In: The Daily Gazette , June 25, 2017, accessed April 19, 2018
  8. ↑ Boy Lüthje : The reorganization of the telecommunications industry in the USA , Springer Verlag, 2013, ISBN 978-3-663-06722-1 , p. 93
  9. ↑ a b Ernst FW Alexanderson . In: Encyclopædia Britannica , accessed April 18, 2018
  10. ↑ KIDNAPPER GETS 10 YEARS .; HC Fairbanks Sentenced for Abduction of Verner Alexanderson. . In: New York Times Archives , November 19, 1925, accessed April 19, 2018
  11. ^ John Brant, Edith Renaud: True Story of the Lindbergh Kidnapping , Kroy Wen Publishers Inc., 1932, p. 189
  12. ^ Bill Buell: Home for big ideas (with photo gallery) . In: The Daily Gazette , May 25, 2010, accessed April 19, 2018
  13. ↑ Ernst Frederic Werner Alexandersson ( Memento of the original from April 19, 2018 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . In: Skagerlind internet archive , accessed on April 18, 2018 @1@ 2Template: Webachiv / IABot / www.skagerlind.net
  14. ↑ IEEE Medal of Honor, Recipients (PDF; 160 kB) on ieee.org , accessed on April 18, 2018
  15. ↑ IEEE Edison Medal, Recipients (PDF; 180 kB) on ieee.org , accessed on April 18, 2018
personal data
SURNAME Alexanderson, Ernst Fredrik Werner
BRIEF DESCRIPTION Swedish-American electrical engineer
DATE OF BIRTH January 25, 1878
PLACE OF BIRTH Uppsala
DATE OF DEATH May 14, 1975
Place of death Schenectady