Self-Tunable Vibration Energy Harvester

Abstract In this paper we present a small self-tunable vibration energy harvester with an integrated electronic circuit board. The changing of the frequency is realized by a stepper motor which moves an anchor. By moving the anchor the effective length of the cantilever beam is changing and as a result the Eigen-frequency changes. The simulations and experimental results are shown for a proof-of-concept and a designed demonstrator in two configurations with a bandwidth of 12 to 30.5 Hz and 19 to 40 Hz. Depending on several factors the possible tuning resolution is between 0.2 and 2 Hz which allows an efficient energy harvesting in the given frequency range.</jats:p

Power Management with Dynamic Power Adaption for a Rotational Energy Harvester in a Maritime Gearbox

Abstract Rotational Energy Harvesting becomes increasingly important for rotating sensor applications. Most of these applications rotate with changing revolution speed, which is a significant challenge for the energy harvesting system. This work presents an energy harvesting system for rotational motion with a new power management concept to generate energy for a wireless condition monitoring system. The challenge is to generate enough energy with a high efficiency factor at the minimum revolution speed but also to avoid problems with energy excess and high voltages at the maximum revolution speed. The power management includes solid state relays for coil switching to avoid the generation of excess energy that would lead to increased temperature. At 500 rpm the energy harvester generates 193 mW. With an efficiency of 54% the power management provides an output power of 106 mW.</jats:p

Aim: To review the 8-year experience of the Department of Esophagogastric Surgery, First Surgical University Hospital in Belgrade in the surgical

Surgical experience of the national institution in th