A Robust Energy Management Circuit for Energy Harvesting from Wideband Low-Acceleration Vibrations in Wireless Sensor Screws

Enabling broad use of electromagnetic energy harvesting in wireless sensor screws requires robust systems that work with weak vibrations and varying frequency profiles. This contribution presents an energy management circuit incorporating two cooperating DC-DC converters controlled by self-powered MOSFET switches and a passive voltage multiplier enabling low-voltage start-up. The circuit operates effectively over an acceleration range of 0.07-0.21 g. It consistently harvests energy across a wider frequency range than energy management circuits based on single DC-DC converters. For example, at an acceleration of 0.21 g, the frequency range is 20–30 Hz. Thereby it realizes, e.g. at 25 Hz, an efficiency of 72%. The proposed circuit enables robust energy harvesting in a wide frequency range, supporting wireless sensor operation even under low-vibration conditions typical of industrial predictive maintenance.