Karl Ferdinand Braun

Karl Ferdinand Braun (June 6, 1850 - April 20, 1918) wasGerman physicist.

BornFulda. Educated atUniversityMarburg andUniversityBerlin, receiving his Ph.D.1872. In 1874 he discoveredpoint-contact rectifier effect. He became director ofPhysical Instituteprofessorphysics at Strasbourg1895. In 1897 he builtfirst cathode-ray tube oscilloscope,CRTstill called"Braun tube" atUniversityKarlsruhe, Germany. He also worked on wireless telegraphy from 1898, inventingcrystal rectifierGuglielmo Marconi admitted'borrowing' from Braun's patents. In 1909 Braun sharedNobel PrizephysicsMarconi"contributions todevelopmentwireless telegraphy."

Braun was detained whileAmerica becausehis German citizenship whenU.S. entered WWI1917. He died beforewar ended1918.

References

• Karl Ferdinand Braun