Flashlight

:"Flashlight" is the NATO designation for the Yakovlev Yak-25 Soviet military jet.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A flashlight or torch is a hand-held portable electric spotlight. It is known as a flashlight mainly in the United States and Canada and as a torch in most Commonwealth countries.

Related Topics:
Spotlight - United States - Canada - Commonwealth

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A typical flashlight consists of a small electric lightbulb with associated parabolic reflector, powered by electric batteries, and with an electric power switch. The components are mounted in a housing that contains the necessary electric circuit and provides ease of handling, a means of access to the batteries for replacement, and a clear covering over the lightbulb for its protection.

Related Topics:
Lightbulb - Parabolic - Reflector - Electric batteries - Electric power switch - Electric circuit

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Although a relatively simple device, its invention did not occur until the late 19th century because it depended upon the earlier invention of the electric battery and electric light. The batteries in the first ones were of such short useful life that the common method of operating them was to flash them just long enough to discern the environs, and only as needed; hence the term "flash-light".

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Recently, flashlights which use light-emitting diodes (LEDs) instead of conventional lightbulbs have become available. LEDs are far more efficient, and use less power than normal lightbulbs. Such torches have longer battery lifetimes. LEDs also survive sharp blows that often break conventional lightbulbs. Another innovation in flashlight design is the headlamp, a flashlight worn on the head for hands-free operation. Powerful headlamps mounted on helmets have been used in mining for decades, but general-purpose ones with fabric straps are now also available.

Related Topics:
Light-emitting diode - Headlamp - Helmet - Mining

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Most flashlights are cylindrical in design, with the lamp assembly attached to one end. However, early designs came in a variety of shapes. Many resembled lanterns of the day, consisting largely of a box with a handle and the lamp attached to the front. Some others were made to have a similar appearance to candles. It is possible that future developments of battery and LED technology will bring interesting new designs. For instance, one very small light that exists now in 2004 consists of a few LEDs with a switch, designed to be an endcap for a 9-volt battery.

Related Topics:
Lantern - Candle - LED - 2004

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

High-quality flashlights go for as much as several hundreds of dollars. Such flashlights are very advanced, using special batteries, have adjustable brightness levels, dive-depth waterproof ratings, interchangeable optics, and are very bright.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~