Small lighting knowledge | who were the first incandescent invented by? - China lighting network

Current flows through a conductor, make it hot and glowing light source, called incandescent bulbs. On October 21, 1879, a great American inventor Thomas Edison in the laboratory they produced the world's first only available for practical incandescent bulbs. Edison summarizing predecessors' experience, improve carbonization method, put a piece of cotton with carbon powder, bent into a horseshoe shape, to make lanterns clay crucible in high temperature heating wire conductor, and then put into glass shell sealed carbon filament, smoke to the air inside, forming the first vacuum carbon filament incandescent lamp. The lamp lit continuously about 45 h, photosynthetic efficiency of 1. 4lm/W。 This is because the carbon although relatively high melting point ( At least 4100 k) , but the emission efficiency is less than 1, and the high rate of evaporation, longevity and cannot be made into high photosynthetic efficiency of the lamp. 1881 design life is 600 h, carbon filament incandescent lights below 20 lm/W. YanZhiXiang

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