Ernst Walter Ruhmer

from Wikipedia, the free encyclopedia

Ernst Walter Ruhmer (born April 15, 1878 in Berlin ; † April 8, 1913 there ) was a German physicist and pioneer of carrier frequency technology .

In his physical laboratory at Friedrichstrasse 248 in Berlin, he improved the selenium cell. He differentiates between hard and soft cells.

Around 1900 he devised the first optical sound recording and reproduction, Photographon , which he reported in Scientific American on July 29, 1901. He modulated a carbon arc lamp with sounds, the light of which he recorded with a film camera with continuous film transport.

From 1902 he experimented with light telegraphy and light telephony, which resulted in a so-called electrolytic telephone in 1904. In December 1902, he and Salomon Kalischer had received DRP 151971 for their method of producing photographic images by exposing electrically conductive plates coated with selenium . He increased the range of Bell's photophone to 10 km and carried out successful experiments with the war and shipbuilding department of Siemens-Schuckert-Werke on the Wannsee.

Then he dealt with X-ray technology and radioactive substances. After 1905, Ruhmer turned to multiple telephony using the "telegraph" he had developed. In 1908 he set up the first carrier frequency system between his apartment and his laboratory. When it was presented at the World Exhibition in Brussels, it had already covered a distance of 15 kilometers.

Works

  • Selenium and its importance for electrical engineering with special consideration of wireless telephony ; Berlin, F. and M. Harrwitz, 1902
  • Newer electrophysical phenomena: Compiled from numerous individual publications ; Verlag Der Mechaniker ; 1902
  • Radium and radioactive substances: using particular a paper given by William J. Hammer to the American Institute of Electrical Engineers and the American Electrochemical Society on April 17, 1903 ; Harrowitz, 1904
  • Design, construction and operation of spark inductors and their application, with special consideration of X-ray technology: in addition to e. Appendix: A brief overview of d. Basics d. X-ray technology d. Doctor ; 1904
  • New apparatus for light telephony. In: Yearbook for Photography and Reproduction Technology ; Ed. 17-1903, pp. 217-219.
  • Wireless telephony . Self-published, Berlin 1907 (English: Wireless telephony, in theory and practice . Crosby Lockwood & Son, London 1908).
  • The talking electric flame arc and its use for "wireless telephony" . In: Elektrotechnische Zeitschrift 22, 1901, pp. 196-198.
  • About the speaking light. In: Physikalische Zeitschrift 2, 1901, pp. 325–328.
  • New transmission and reception arrangement for wireless telephony. In: Physikalische Zeitschrift 2, 1901, pp. 339-340.
  • Recent attempts with light telephony. In: Elektrotechnische Zeitschrift 23, 1902, pp. 859–862.

Individual evidence

  1. ↑ Archive link ( Memento from March 4, 2016 in the Internet Archive )
  2. ↑ http://www.zeno.org/Meyers-1905/A/Fernsprecher
personal data
SURNAME Ruhmer, Ernst Walter
BRIEF DESCRIPTION German physicist
DATE OF BIRTH April 15, 1878
PLACE OF BIRTH Berlin
DATE OF DEATH April 8, 1913
Place of death Berlin