Flashlights,
or electric torches as they are sometimes called consist of an easy
to carry housing that contains a light bulb, a reflector and a power
supply which is usually electric batteries although some flashlights
have hand powered cranks to generate electricity or solar collectors
that store the suns energy until darkness. Most are designed to be hand
held, but headlamps for camping, miners and emergency rescue personnel
are common as well.
The first flashlights were actually used by police in New York City
first. Although the first electric torches did not sustain power for
long, they were very popular and useful to officers. The quick flash
of light that quickly faded was a characteristic of the first portable
lights, which is how the term “flashlight” was coined. Improvements
in battery efficiency and light bulb life have allowed them to become
standard items for homes, cars, campsites and emergency scenes.
Incandescent flashlights are the most common, and consist of a bulb
that contains a wire of tungsten that gives off heat and light when
an electric current is run through it. The bulb is also filled with
gas, usually argon or halogen but higher quality bulbs use xenon. Maglites
are a popular incandescent flashlight and allow owners to make modifications
to increase power output and light. Light emitting diodes, or LED’s
are becoming more popular because of their efficiency.