Electric generating device for a vehicle

A power-generating device for a vehicle is disclosed, which comprises an oscillation system (3, 4; 3, 14), an induction unit (2), a sensor (17), and a control unit (8). The oscillation system (3, 4; 3, 14) has a movably arranged oscillating mass (3), and the induction unit (2) serves for the inductive conversion of kinetic energy of the oscillating mass (3) into electrical energy. The sensor (17) serves for determining a vibration frequency of the vehicle, and the control unit (8) serves for adjusting the resonance frequency of the oscillation system (3, 4; 3, 14) to a determined vibration frequency of the vehicle.