And by he had a working prototype, but the lack of a good vacuum and an adequate supply of electricity resulted in a bulb whose lifetime was much too short to be considered an effective prodcer of light. In , Swan developed a longer lasting light bulb using a treated cotton thread that also removed the problem of early bulb blackening.
They built their lamps with different sizes and shapes of carbon rods held between electrodes in glass cylinders filled with nitrogen. Woodward and Evans attempted to commercialize their lamp, but were unsuccessful. They eventually sold their patent to Edison in In , Thomas Edison began serious research into developing a practical incandescent lamp and on October 14, , Edison filed his first patent application for "Improvement In Electric Lights".
However, he continued to test several types of material for metal filaments to improve upon his original design and by Nov 4, , he filed another U. Although the patent described several ways of creating the carbon filament including using "cotton and linen thread, wood splints, papers coiled in various ways," it was not until several months after the patent was granted that Edison and his team discovered that a carbonized bamboo filament could last over hours.
The remaining energy is lost as heat. However these inefficient light bulbs are still widely used today due to many advantages such as:. Unfortunately for the incandescent bulb, legislation in many countries, including the US, has mandated phasing it out for more energy-efficient options such as compact fluorescent lamps and LED lamps.
There has been much resistance, however, to these policies owing to the low cost of incandescent bulbs, the instant availability of light and concerns of mercury contamination with CFLs.
More than years ago, inventors began working on a bright idea that would have a dramatic impact on how we use energy in our homes and offices. This invention changed the way we design buildings, increased the length of the average workday and jumpstarted new businesses.
It also led to new energy breakthroughs -- from power plants and electric transmission lines to home appliances and electric motors. It was a series of small improvements on the ideas of previous inventors that have led to the light bulbs we use in our homes today.
Long before Thomas Edison patented -- first in and then a year later in -- and began commercializing his incandescent light bulb, British inventors were demonstrating that electric light was possible with the arc lamp. These early bulbs had extremely short lifespans, were too expensive to produce or used too much energy. When Edison and his researchers at Menlo Park came onto the lighting scene, they focused on improving the filament -- first testing carbon, then platinum, before finally returning to a carbon filament.
Edison also made other improvements to the light bulb, including creating a better vacuum pump to fully remove the air from the bulb and developing the Edison screw what is now the standard socket fittings for light bulbs. Edison modeled his lighting technology on the existing gas lighting system. In with the Holborn Viaduct in London, he demonstrated that electricity could be distributed from a centrally located generator through a series of wires and tubes also called conduits.
Simultaneously, he focused on improving the generation of electricity, developing the first commercial power utility called the Pearl Street Station in lower Manhattan. And to track how much electricity each customer was using, Edison developed the first electric meter. While Edison was working on the whole lighting system, other inventors were continuing to make small advances, improving the filament manufacturing process and the efficiency of the bulb.
The next big change in the incandescent bulb came with the invention of the tungsten filament by European inventors in These new tungsten filament bulbs lasted longer and had a brighter light compared to the carbon filament bulbs. Yet the British chemist Warren de La Rue had solved the scientific challenges nearly 40 years earlier. He used thin — and thus high-resistance — filaments to achieve the brightness, and delayed burnout by making them from high-melting-point metal sealed in a vacuum.
His choice of pricey platinum for the filament and the difficulties of achieving a good vacuum made the result uneconomic, however.
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