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Vacuum Sealed Glass Envelope Lighting Technology- Light Bulbs
The basic incandescent light bulb invented by Thomas A. Edison was the mainstay of conventional home electrical lighting until the late 1990's when the move to conserve energy cutting down use of fossil fuels and cut down the carbon footprint in the atmosphere became the cry from activist groups influencing state and federal governments to move toward a "greener" technology. Compact Fluorescent Bulbs were the mainstay from the 1990's until around 2017, they were more efficient and saved significant amount of energy. Their shortcomings were the style and they tend to take a minute or two to get to maximum light output. All of these vintage technology items have one thing in common, lighting comes out of a vacuum sealed glass envelope.
The Light Emitting Diode or LED Bulb has now become the standard light source. They are more efficient and energy saving than CFL's. Their small size and the ability to produce them in many colors makes them very versatile in a wide range of lighting applications
The Original Incandescent Light Bulb (1870s-2017)
Basically unchanged since its discovery. Advances in filament materials, bulb coatings, bulb shapes, and filament shapes have been made throughout the 19th and 20th century. 90% of the energy is wasted as infrared radiation (heat). The wattage of the bulb indicates the light output and energy consumption.They are being replaced by LED lighting which reduce energy consumption up to 70%. As of 2017 incandescent bulbs are being phased out except for special purpose applications.
Early Style with Nipple or Pinched Vacuum Tips
Common before 1920. Bulb on the right is a General Electric Mazda Lamp circa 1912-13. 40 Candle Power 1.75 A rating with Mogul size Edison screw base. MAZDA is a GE trademark introducing the metalized filament in 1904, providing more light than the original carbon filament used by Edison.
Typical Mid to Late 20th Century bulb shapes and bases
Traffic Light type bulbs
The filament must be on a plane allowing maximum light to be seen forward. Sometimes a mini reflector is added at the base to direct more light forward. Traffic light bulbs have heavier duty filaments and often are rated for 130 VAC for longer service life.
Energy Saving Incandescent Type Bulbs (1990s-present)
These are bulbs incorporating Halogen compounds inside the vacuum area. Halogen allows the bulb to put out more light at a 20-30% energy savings. The use of Halogen bulbs goes back to the mid 20th century. Their shortcomings are, bulb area must be small and pressure high to get the bright light. The small bulb area makes these bulbs very hot and can cause a fire if near combustibles. They have a relatively short life.
Halogen
LEFT:Philips Halogena40W Halogen=60W
General Electric Reveal 29W Halogen=40W
RIGHT:Inside a Halogen Incandescent Bulb.Notice how small the glass bulb is in the center.
Compact Fluorescent Bulbs (CFL) 1990s-2018
The practical fluorescent bulb is an early 20th century invention. A coated glass tube is lit up by a stream of charged particles under pressure called a plasma stream. These particles are produced by a heated filament then with a small amount of mercury, a small arc is produced and the particles are accelerated across the tube. Particles that strike the coated tube provide energy to the electrons on the coating. These energized electrons give of energy on the form of visible light and UV radiation. This method of producing light is called fluorescence. Naturally if the velocity of the plasma is maintained, common sense says the longer the tube the more light output and light spread. Before CFL's, fluorescent were straight glass tubes, the longer ones were higher wattage and provided more light. These bulbs were much more energy efficient than traditional incandescent bulbs. However these tubes and associated plasma producing circuitry (aka the starter or ballast) were not very attractive or home friendly, and were limited to the garage and kitchen. If we were able to take that straight tube and make a tight spiral, and miniaturize the starter circuitry, fluorescent bulbs may be able to fit inside a lamp or ceiling fixture. In the 1990's the compact fluorescent light bulb was born. The table below shows the power consumption to produce the same amount of light
incandescent versus a compact fluorescent bulb
Standard Bulb to CFL Bulb Equivalent
40w = 10w
60w = 13w-15w
75w = 20w
100w = 26w-29w
150w = 38w-42w
Common Fluorescent Lamp Shape Before CFL's
Top is a Philips F6T5/BL UV or Black Light Tube. Without the glass coating fluorescent lamps will emit UC radiation
Bottom is a Philips F4T5/CW fluorescent Tube.
The External Spiral CFL (1997)
Earliest and most common style
The External Compact Spiral CFL
Consumers love the old fashion incandescent bulb. Fixtures were designed around that classic shape. Spiral CFL's were just ugly and made light fixtures look like something from a Frankenstein movie. In the early 2000's manufacturer's came out with the compact spiral that made the CFL less noticeable.
The Encapsulated Spiral CFL (2006)
Looking like the incandescent bulb and almost the same size. Manufacturers place a translucent plastic dome over the spiral which helps cut down the harshness. Later glass was used and were inside frosted like regular bulbs were. Definitely were more appealing to consumers.
"Reveal" is a GE trademark for the use of Neodymium oxide ( Nd2O3 ) coating on the inside glass. When such bulbs are not lit, they have a powder-blue color. When they are lit, their special coating filters out much of the dulling yellow cast produced ordinary light bulbs, producing a light that seems purer, more like sunlight.
COLOR CFL Bulbs
A coating is added to provide the desired color.
CFL Flood Type Bulbs
Special Purpose Light Bulbs
High Pressure Sodium (HPS) Lamps
Being replaced with LED area lighting
Mercury Vapor
Invented 1896, no longer used for new applications
The Emergence of LED Light Bulbs (2000s-on)
SHOWCASE
Science Teaching Kit: How an Incandescent Light Bulb is Made
Verd-A-Ray Corporation
Toledo Ohio 43614
The Scientific Light Bulb Kit
Found this at an antique mall. Shows how incandescent bulbs are manufactured.
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