Mechanically powered flashlight

A dynamo flashlight is an electric lamp, which is mechanically driven by a small electric generator by muscle power. This allows the operation of the lamp in the period of a few seconds, allowing for constructions with a built in light small flywheel as a temporary energy storage up to a few minutes. Conventional flashlights have a power supply by batteries or accumulators.

First mechanical dynamo flashlights are from the early 20th century, could not be used in any position as early as the Daniell cell batteries.

Function

For driving the generator, various methods exist. Common method is a built- in light lever which needs to be moved down periodically, or the drive is provided by a small hand crank. Furthermore, there are also configurations where a flywheel is rotated by pulling a thread which drives the generator for a short period. Unlike conventional flashlights no switch is necessary for functional reasons for the luminaire. As a light source, in addition to small bulbs also LED lamps and fluorescent lamps are used. The power is in the order to 1 W.

Applications

Since mechanical, driven purely by muscle power dynamo flashlights are not dependent on the availability and operability of electrical energy storage such as electric batteries, electric batteries have a limited amount of time due to the self-discharge on, find dynamo flashlights, among other things as an emergency light application. The advantage is the virtually unlimited shelf life of these lamps. Due to the simple structure can be found in various forms as examined and experimented object in physical education use.

Dynamo flashlights are also used in applications where the availability of commercial electric batteries is not guaranteed, such as in rural areas of Africa.