The electric light bulb is one the most abiding symbols of technical advancement. From its early conception at the turn of the 19th century to the present day where the image of the light bulb is still used to represent the notion of a good idea, the design of the light bulb has changed relatively little. However, with efficiency requirements and customer tastes becoming more advanced lighting technology is once again changing rapidly. In this article I will chart the progress of the light bulb.
The electric light bulb is one the most abiding symbols of technical advancement. From its early conception at the turn of the 19th century to the present day where the image of the light bulb is still used to represent the notion of a good idea, the design of the light bulb has changed relatively little. However, with efficiency requirements and customer tastes becoming more advanced lighting technology is once again changing rapidly. In this article I will chart the progress of the light bulb, starting with the earliest experiments with platinum filaments to today’s most advanced LED bulbs.
One of the most consistent and interesting themes in this subject area is the aversion to change that inventors and innovators contend with at each new technological advancement. This point can be illustrated with the candle light bulb; the bulb was designed to replicate the aesthetics of a candle in fittings such as chandeliers (the earliest chandeliers were purely functioning as a way of increasing the light output from candles). The candle shaped bulb is now one of the most popular CFL styles due to the potential cost savings from multiple bulb fittings.
When discussing the incandescent lamp one name features more prolifically than any other, Thomas Edison. Historians Robert Friedel and Paul Israel named over twenty inventors of the light bulb before Edison, however they concluded that Edison’s design surpassed earlier attempts because of effective incandescent material, a higher vacuum and higher resistance making the bulb easy to power and therefore economically viable.
Thomas Hughes ascribed the success of Edison’s design to the fact he had invented an entire lighting system, ‘other inventors with generators and incandescent lamps, and comparable ingenuity and excellence, have long been forgotten because their creators did not preside over their introduction in a system of lighting’ (Hughes).
The first incandescent light was created by Humphry Davy in 1802, 45 years before Edison was born, by passing an electric current through a thin strip of platinum, chosen for its high melting point. The light produced was not bright enough nor did it last long enough to be practical.
James Lindley took up the baton in 1835 demonstrating his electric light at a public meeting; however he then turned his attention to other fields leaving the way clear for Walter De la Rue. In 1840 De la Rue passed an electrical current through a coiled platinum filament- enclosed in a vacuum. The theory being that an evacuated bulb would contain fewer gas molecules to react with the platinum, thus prolonging its illumination time. This was a significant advancement; however the use of platinum made the design unfeasible for commercial use.
In 1858 Joseph Wilson Swan began working with carbonised paper filaments but was hindered by the lack of a good vacuum until he teamed up with Charles Stearn, an expert on vacuum pumps. Swan then turned his attention to efficiency, producing better carbon filaments, and in 1880 he began installing light bulbs in his home in Gateshead, England.
Thomas Edison began research into the incandescent lamp in 1878, settling on the carbon filament. His first test in 1879 lasted for 13.5 hours, however several months later Edison discovered that a carbonised bamboo filament could last for over 1200 hours.
Meanwhile in the U.S Hiram S. Maxim started his United States Electric Lighting Company becoming the second man, after Edison, to install incandescent lamps at the Mercantile Safe Deposit Company in New York City. Edison and Swan joined forces to form Ediswan (later to become Thorn lighting), and eventually Edison acquired all of Swan’s interests in the company.
Advancements continued and in 1910 William David Coolidge invented a method of making tungsten filaments more efficient, making the light bulb even more cost effective.
From 1913 to 1930 innovators turned their attentions to the use of inert gases in the bulb to improve efficiency further. In 1930, Imre Brody settled on a mix of krypton and xenon and to reduce costs, also developed a method of capturing krypton from air at his factory in Ajka, Hungary.
The latest significant development in the lighting sector has been the introduction of ‘energy saving’ light bulbs or compact florescent light bulbs (CFLs). Although they are considered a relatively modern invention CFLs were first conceived by Pete Cooper in the late 1980s and were originally used in the photography industry. The first practical florescent lamp was designed by George Inman from General Electric and became the blueprint for the modern CFL invented by Ed Hammer and General Electric in response to the 1973 oil crisis. Although the design met all of its requirements, it was never mass manufactured due to the cost of mass production, however the design was subsequently leaked and copied.
The steady increase in CFL production continues to this day but with the phasing out of inefficient incandescent bulbs, consumption is expected to increase more sharply. By September 2012 no incandescent bulbs will be available reducing carbon emissions and consumer energy costs.
So what is the future of electric lighting? Many people believe that the answer lies with LED bulbs. Originally used in devices such as alpha numerical displays and pocket calculators the LEDs have recently seen successful application in commercial and domestic lighting. LEDs can last for up to 50,000 times as long as incandescent bulbs and the most advanced bulbs can produce a high light output while consuming a fraction of the energy. Although the initial cost of the lighting is high, the bulbs will more than pay for themselves in their lifetime. LED bulbs have a fast on/off time and can withstand a high frequency of cycling making them ideal for car headlights, theatrical spotlights, traffic lights and dynamic road signs as well as household and domestic lighting.
It is clear that lighting technology has come a long way since Edison’s first experiments and the contact we have with lighting everyday encourages advancements to continue.
Please visit Greenhouse Organisation for all your energy saving light bulbs.
