Freidenberg, Mikhail Filippovich
(also Moisei Freidenberg). Born Jan. 9 (21), 1858, in Prasnysh, now Przasnysz, Poland; died Aug. 1, 1920, in Petrograd. Russian inventor.
In 1893, Freidenberg, working with I. A. Timchenko, invented a motion-picture projector similar to the Kinetoscope. In the same year, Freidenberg and S. M. Berdichevskii-Apostolov constructed a model of an automatic telephone central office. Freidenberg developed and patented a preselector (1895), a power-driven selector (1896), and a group selector for an automatic central office with a 10,000-subscriber capacity (1896). In 1908, Freidenberg designed a typecasting machine.