Crank Flashlights, Lanterns and Radios
Mechanically powered flashlights including crank and shake have seen significant marketplace acceptance due to their ability to generate their own power to recharge a NiMH battery, Lithium battery or capacitor. Earlier version of the technology stored energy in a spring but with the introduction of improved energy storage cells this design is becoming rare.
Crank Device Evolution
Initially crank flashlights were seen as limited to being an emergency light but that perception has changed with design improvements in energy storage and multi-function capabilities including introduction of radio chips capable of receiving AM, FM and in more advanced models NOAA emergency broadcast frequencies. Emergency radios often times include an alarm that can be manually or in some radios automatically activated. Crank devices are frequently used for recreational outings and general convenience.
Multiple lighting configurations are now common where a crank device incorporates a variety of LED configurations useful as a flashlight or lantern. Supporting emergency rescue many crank lights also include a flashing beacon function that emits an SOS signal often times using a red LED.
Recognized Green Technology
Crank devices come in a variety of sizes from pocket units to models designed for table tops. Design improvements in dynamo efficiency are such that a few minutes of cranking can provide up to an hour or more of use depending on the function selected, i.e. light vs. radio. The high efficiency nature of crank devices add to their versatility of use and are typically classified as a green technology because of the ability for continuous operation without replacing batteries.
Adding to the flexibility of crank flashlights and lanterns is the additional option to recharge certain crank devices through inclusion of a solar panel, computer USB adaptor, DC auto adaptor and AC adaptor. Crank devices also function as a generator and offer the capability of recharging low voltage devices such as cell phones and music players.
Although no longer limited to the realm of emergency flashlight and radio it cannot be overstated the value crank devices provide to individuals around the world when disasters strike. The ability to stay informed when natural or man caused disasters occur, to create light when the power grid is down and the ability to bring attention to rescuers when injured or trapped is readily available with a crank device.