© Fonds historique / CNRS Photothèque
Electromagnetic flashlight photographed on October 27th, 1923. Mr. Lorin’s electromagnetic flashlight (with an air turbine) was first proposed at the ONRSII’s mechanics laboratory and aimed to provide a more durable alternative to the battery run flashlight. It was fed by a small dynamo or magneto-powered electric machine. The necessary driving force was provided by human energy. While a standard battery did not require any physical effort to run, this flashlight did. It was more tiresome to work but much more durable. The flashlight was lightweight and its performance was satisfactory, despite the significant energy loss brought upon by hysteresis and eddy currents. Once put into action, the device slowly continued to function for another 15 to 20 seconds as the bulb’s filament progressively faded out. The flashlight was also moisture resistant. Office national des recherches scientifiques et industrielles et des inventions.