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During World War II, Germany developed a hand-crank 500 kHz rescue radio, the "Notsender" (emergency transmitter) NS2. It used two vacuum tubes and was crystal-controlled. The radio case curved inward in the middle so that a user seated in an inflatable life boat could hold it stationary, between the thighs, while the generator handle was turned.
In the most common arrangement, an internal electric generator is run by a mainspring, which is wound by a hand crank on the case. Turning the crank winds the spring and a full winding will allow several hours of operation. Alternatively, the generator can charge an internal battery.
Harris Corporation was an American technology company, defense contractor, and information technology services provider that produced wireless equipment, tactical radios, electronic systems, night vision equipment and both terrestrial and spaceborne antennas for use in the government, defense, emergency service, and commercial sectors.
The user repeatedly squeezes a handle to spin a flywheel inside the flashlight, attached to a small generator/dynamo, supplying electric current to an incandescent bulb or light-emitting diode. The flashlight must be pumped continuously during use, with the flywheel turning the generator between squeezes to keep the light going continuously.
A telephone magneto is a hand-cranked electrical generator that uses permanent magnets to produce alternating current from a rotating armature. In early telegraphy , magnetos were used to power instruments, while in telephony they were used to generate electrical current to drive electromechanical ringers in telephone sets and activate signals ...
In present Freeplay radios and other products, clockwork mechanisms storing energy in a mainspring have now been replaced by small batteries charged by cheaper hand-crank generators. [9] Freeplay Energy produces a variety of consumer devices in addition to radios, including flashlights, lanterns, mobile phone chargers, and foot-powered generators.
The first field telephones had a battery to power the voice transmission, a hand-cranked generator to signal another field telephone or a manually-operated telephone exchange, and an electromagnetic ringer which sounded when current from a remote generator arrived. This technology was used from the 1910s to the 1980s.
Demonstration hand-cranked magneto made circa 1925, on display at the Musée d'histoire des sciences de la Ville de Genève. 2kW Société de l'Alliance magneto generator for arc lamps, of around 1870. A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current.