Friedrich von Hefner-Alteneck
Hefner-Alteneck, Friedrich von
Born Apr. 27, 1845, in Aschaffenburg, in what is now the Federal Republic of Germany; died Jan. 7, 1904, in Berlin. German electrical engineer. Member of the Royal Swedish Academy of Sciences (1896) and the Prussian Academy of Sciences (1901).
Hefner-Alteneck graduated from the Swiss Federal Institute of Technology. From 1867 to 1890, he was the chief designer and engineer of the Siemens and Halske firm.
Hefner-Alteneck invented numerous devices for electrical engineering, illuminating engineering, telegraphy, and photometry. In 1873 he invented the drum armature for DC electric motors. In 1884 he proposed a standard, called the Hefner candle, for the measurement of luminous intensity.