Citizen once made a series of watches powered only by the temperature

Citizen once made a series of watches powered only by the temperature

Citizen once made a series of watches powered only by the temperature difference between the wearers skin and the ambient air Citizen Eco-Drive Thermo watches were introduced in 1999 and use the temperature difference between the wearer’s arm and the surrounding environment as a power source. The rare Eco-Drive Thermo watches use the Seebeck effect […]