AllBiographies' Forum Our Dictionary Our Math Site

search biography names   match all words match any words use wildcards  browse biographies get a new biography browse by name browse by year  browse by category Top 100 Categories Categories 101-300 Categories 301-500 Categories 501-633 English Dictionary allmath.com math for students travel deals hotel rooms allbiographies.com privacy policy

biography classifications major works cross references biography name: Poulsen, Valdemar sex: male lived: (1869–1942) biography: Electrical engineer, born in Copenhagen, Denmark. Working for the Copenhagen Telephone Company, he invented the telegraphone, a wire recording device, forerunner of magnetic tape recorders (1898). In 1903 he also invented an arc generator for use in wireless telegraphy. browse by name A B C D E F G H I J K L M N O P Q R S T U V W X Y Z browse by year   2700 - 691 BC 690 - 531 BC 530 - 481 BC 480 - 391 BC 390 - 281 BC 280 - 131 BC 130 - 61 BC 60 BC - 29 AD 30 - 109 110 - 239 240 - 329 330 - 409 410 - 549 550 - 639 640 - 799 800 - 899 900 - 979 980 - 1039 1040 - 1099 1100 - 1139 1140 - 1179 1180 - 1219 1220 - 1249 1250 - 1279 1280 - 1319 1320 - 1349 1350 - 1379 1380 - 1549 1550 - 1649 1650 - 1659 1660 - 1749 1750 - 1789 1790 - 1819 1820 - 1839 1840 - 1859 1860 - 1869 1870 - 1879 1880 - 1889 1890 - 1899 1900 - 1909 1910 - 1919 1920 - 1929 1930 - 1939 1940 - 1949 1950 - 2005 No Birth Date