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Pogledaj Full Version : Franjo Hanaman - Inventor of first economical / commercially viable light bulb



Željko Zidarić
30th-May-2012, 02:39 AM
Franjo Hanaman (1878 in Drenovci -1941), 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.

Prvu masovno prihvatljivu električnu žarulju izumio je i patentirao prije sto godina u Beču hrvatski znanstvenik Franjo Hanaman (rođen 1878. u Drenovcima kraj Županje), zajedno s austrijskim znanstvenikom dr. Alexanderom Justom. Volframova žarulja učinila je snažan preokret u proizvodnji rasvjetnih tijela jer je vrlo brzo potisnula plinsku rasvjetu i sijalice s grafitnom niti, te još i danas rasvjetljuje najviše domova širom svijeta. Nedostatak prvih žarulja bile su krhke niti volframa. Postupak do proizvodnje upotrebivih žarulja trajao je nekoliko godina i bio praćen razočaranjima, a završen je u Americi 1910. kad je dobivena nit zadovoljavajuće čvrstoće i elastičnosti. Već je iste te godine žarulja s volframovom niti preuzela prvo prodajno mjesto. Godine 1910., patentna prava otkupio je američki General Electric za 250.000 dolara od čega je autorima pripala trećina.



http://www.youtube.com/watch?v=CrgQ1EVi8qI

Wikipedia - Hrvatski (http://hr.wikipedia.org/wiki/Franjo_Hanaman) - English (http://en.wikipedia.org/wiki/Franjo_Hanaman) - Deutsche (http://de.wikipedia.org/wiki/Franjo_Hanaman)

A very good article on Hanaman is found on page 11 of this Croatian PDF (http://www.hep.hr/hep/publikacije/vjesnik/132.pdf)

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