more at
‘HISTORY OF VARIOUS WAYS IN WHICH MAN HAS OBTAINED LIGHT, FROM EARLY USE OF FIRE TO ELECTRIC LIGHTING. FEATURES STRINGLESS PUPPETS PRODUCED BY JOOP GEESINK. A General Electric “Excursion in Science.”‘
NEW VERSION with improved video & sound:
Public domain film from the Prelinger Archive, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
An electric light is a device that produces light by the flow of electric current. It is the most common form of artificial lighting and is essential to modern society, providing interior lighting for buildings and exterior light for evening and nighttime activities… The two main families of electric light are incandescent lamps, which produce light by a filament heated white-hot by electric current, and gas-discharge lamps, which produce light by an electric arc through a gas…
The most efficient source of electric light is the low-pressure sodium lamp. It produces, for all practical purposes, a monochromatic orange/yellow light, which gives a similarly monochromatic perceprtion of any illuminated scene…
Incandescent light bulb
The modern incandescent lightbulb, with a coiled filament of tungsten, was commercialized in the 1920s developed from the carbon filament lamp introduced in about 1880. As well as bulbs for normal illumination, there is a very wide range, including low voltage, low-power types often used as components in equipment, but now largely displaced by LEDs
There is currently interest in banning some types of filament lamp in some countries, such as Australia planning to ban standard incandescent light bulbs by 2010, because they are inefficient at converting electricity to light. Sri Lanka has already banned importing filament bulbs because of high use of electricity and less light. Less than 3% of the input energy is converted into usable light. Nearly all of the input energy ends up as heat that, in warm climates, must then be removed from the building by ventilation or air conditioning, often resulting in more energy consumption…
Halogen lamp
Halogen lamps are usually much smaller than standard incandescents, because for successful operation a bulb temperature over 200 °C is generally necessary. For this reason, most have a bulb of fused silica (quartz), but sometimes aluminosilicate glass. This is often sealed inside an additional layer of glass…
Fluorescent lamp
Fluorescent lamps have much higher efficiency than filament lamps. For the same amount of light generated, they typically use around one-quarter to one-third the power of an incandescent.
Fluorescents were mostly limited to linear and a round ‘Circline’ lamp until the 1980s, with other shapes never gaining much popularity. The compact fluorescent lamp (CFL) was commercialized in the early 1980s.
Most CFLs have a built-in electrical ballast and fit into a standard screw or bayonet base. Some make use of a separate ballast so that the ballast and tube can be replaced separately.
Typical average lifetime ratings for linear fluorescent tubes are 10,000 and 20,000 hours, compared to 750 hours (110 V) and 1000 hours (240 V) for filament lamps.
Some types of fluorescent lamp ballast have difficulty starting lamps in very cold conditions, so lights used outdoors in cold climates need to be designed for outdoor use to work reliably.
Fluorescents come in a range of different color temperatures. In some countries cool white (CW) is most popular, while in some, warmer whites predominate.
In the United States, fluorescents most often come in cool white (CW), with some home bulbs being a warm white (WW), which has a pinkish color. In between there is an “enhanced white” (EW), which is more neutral. There is also a very cold daylight white (DW)…
LED lamp
Solid state LEDs have been popular as indicator lights since the 1970s. In recent years, efficacy and output have risen to the point where LEDs are now being used in niche lighting applications.
Indicator LEDs are known for their extremely long life, up to 100,000 hours, but lighting LEDs are operated much less conservatively (due to high LED cost per watt), and consequently have much shorter lives.
Due to the relatively high cost per watt, LED lighting is most useful at very low powers, typically for lamp assemblies of under 10 W…
