Page 183 - Inventions - A Visual Encyclopedia (DK - Smithsonian)

EDISON’S BRIGHT IDEA
A year after Swan demonstrated his bulb, the
Almost total American inventor Thomas Edison (see pp.186–187)
vacuum
inside bulb came up with his own version, using a filament
made of carbonized (charred) bamboo.
Edison ensured its popularity by also
devising the electricity-generating
power plants and distribution
systems that powered the
lights, bringing electricity into
millions of people’s homes
for the first time.
MODERN BULBS
Today, many incandescent light bulbs (which create AT HOME
light by heating a filament—a wire—in the bulb) are
Loop-shaped being replaced in homes with more energy-efficient
filament options. These include compact fluorescent bulbs
(see p.183) and light-emitting diodes (LEDs), such
as the ones shown above. Some LED lights can be
controlled with a smart device, such as a phone,
Connecting wires deliver linked to a central control hub.
electric current.

COMPARING BULBS

Coiled filament made 3. Strips of LEDs
from tungsten glow when the
current passes
through them.
Electric current
flows through wires
connected to the 2. Electric
filament, heating current flows
it up so that it glows through the wire.
and gives out light.
1. Current enters
Incandescent LED through electronic
Electrical light bulb light bulb control circuits
contact hidden in the base.
When you flick the switch, an electric An LED is made of a material called a
current passes through the bulb’s filament, semiconductor. When you flick the switch,
making it glow. Because the bulb contains charged particles called electrons move
nonreactive gases instead of oxygen, through this material, creating energy in
the filament doesn’t burn out quickly. the form of light.

◀ JOINING FORCES
This early Edison light bulb dates from 1879. Despite initial
disagreements over patents for their invention, Swan and
Edison joined forces in 1883 to form the Edison and Swan
United Electric Company, later called Ediswan, in Britain.
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