(June 30, 1878 in Drenovci near Županja
– January 23, 1941 in Zagreb)
Franjo Hanaman - Inventor of first economical / commercially viable light bulb
Franjo Hanaman (June 30, 1878 in Drenovci near Županja, Kingdom of Croatia-Slavonia, Austria-Hungary– January 23, 1941 in Zagreb, Kingdom of Yugoslavia - Croatia today).
Franjo Hanaman was born to a Croatian family as a second child of father Gjuro Hanaman and Emilija Mandušić.
First economical / commercially viable light bulb -
- Dr.Just-Wolframlampe, name Francis Hanaman was unfairly omitted.
He was a Croatian inventor, engineer, and chemist, who gained world recognition for inventing the world's first applied electric light-bulb with a metal filament (tungsten) with his assistant Aleksandar Just, independently of his contemporaries. They were granted the Hungarian Patent #34541 on December 13, 1904 on Budapest. His invention of tungsten filament was also applied in improving early diodes and triodes.
Franjo Hanaman, chemist and metallurgist, together with Aleksandar Just invented the first economical / commercially viable electric bulb with tungsten (wolfram) filament. The Hungarian patent (No. 34541) was granted on December 13, 1904. The problem with the old carbon fibber based lamps was that they were not very bright and had a short lifespan. Edison's bulb which was based on a carbonized bamboo filament could last over 1200 hours and were sensitive to vibration. The new tungsten based bulbs were much brighter (working temperature of about 2500° C) and lasted much longer than the originals. Efficiency ratings for the original carbon lamps was 1.7 lumens per watt while the new tungsten filament produced 7.75 lumens per watt. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1905, so this type is often called Tungsram-bulbs in many European countries. During his travels to the USA in 1910, Hanaman sold his patent rights to the General Electric Co. for $250,000 of which one third went to the patent holders.
Light bulb trivia: The cost of the incandescent lamp has constantly been reduced and efficiency increased. In 1907 the 60-watt lamp gave 8 lumens per watt and lost 25 percent of this light before burning out. Thirty years later the 60-watt lamp produced 13.9 lumens per watt and emitted 90 percent of its original light at the end of its life. By the 1970s developments had brought the number of lumens produced in a tungsten-filament lamp to 40, the maximum obtainable before the filament melts.
1. ^ Moser, Josip (January 2002). "FRANJO HANAMAN I NJEGOVO DJELO" (in Croatian) pp. 11–3. http://www.hep.hr/hep/publikacije/vjesnik/132.pdf. Retrieved 2009-01-04.
2. ^ "Text of Patent" (in Hungarian). December 13 1904. http://www.mszh.hu/anim/HU-34541.pdf. Retrieved 2009-01-04.