Hehkulampun

Hehkulampun, commonly known as an incandescent light bulb, is an electric light source that produces light by means of a filament heated to a high temperature by an electric current. The filament is typically made of tungsten and enclosed in a glass bulb filled with an inert gas or a vacuum to prevent oxidation. When electricity flows through the filament, it heats up and glows, emitting visible light.

The principle behind the incandescent bulb was first demonstrated by Humphry Davy in 1802, but practical, long-lasting versions were developed by inventors like Thomas Edison and Joseph Swan in the late 19th century. Edison's innovation was crucial in developing a commercially viable and durable bulb.

Incandescent bulbs are characterized by their warm, yellowish light and their relatively low luminous efficacy, meaning they convert a significant portion of electrical energy into heat rather than light. This inefficiency led to their gradual replacement by more energy-efficient lighting technologies such as fluorescent lamps and LED lights. Despite their decline in general use, incandescent bulbs are still sometimes favored for specific applications where their particular light quality or low initial cost is desirable, or in historical recreations. Their production and sale have been phased out in many regions due to energy efficiency regulations.