Edison's greatest contribution in his life was to invent the electric light. He made more than 16 experiments on heat-resistant materials and more than 6 kinds of plant fibers before he made the first light bulb. Later, on this basis, he constantly improved the manufacturing method. In order to promote the use of electric lights, he developed various additional equipment for electrical systems such as parallel circuits, fuses, insulating materials, copper wire networks, etc. It also made a generator with stable voltage and a three-wire switch for economical distribution. In 1882, he set up an electric power network in new york. Although he used direct current transmission method to limit the distance of transmitting electricity, this great contribution has greatly improved human life.

Edison discovered the thermionic emission phenomenon in p>1883, which laid the foundation for the appearance of electron tubes. In 1887, he set up a larger laboratory in West Orange. His inventions there are numerous, among which the most important one is the movie camcorder in 1888; The 1896 film projector and ferronickel? Batteries. His successive inventions won him a special gold medal in Congress in 1928.