Electrodynamic Generator Research Articles

Power density improvement of the power conditioning circuit for combined piezoelectric and electrodynamic generators

In this study, we report a power management circuit for a combined piezoelectric- electrodynamic generator. A piezoelectric element is bonded to a spring steel cantilever beam and a magnet, used as tip mass, oscillates through a coil. This principle creates the combined generator. A test setup has been created to automate the characterization of the piezoelectric generator and its power management circuit. Three different power management circuits for the piezoelectric part of the combined generator have been analysed: a bridge rectifier, an SSHI circuit with an external inductance and an SSHI circuit which utilizes the coil of the electrodynamic generator as circuit element. The three circuits are compared in terms of their output power, efficiency and power density. The SSHI circuit with an external inductance has the highest output power and efficiency, followed by the SSHI circuit with the electrodynamic generator coil. The power density of the bridge rectifier is the highest but for higher efficiency the power density of the SSHI circuit with the coil of the electromagnetic generator reaches the best results.

Modeling of Hybrid Piezoelectrodynamic Generators

AbstractVibrational energy harvesters are used for collecting electrical power from mechanical vibrations and supplying low power applications. Combining a piezoelectric generator with an electrodynamic generator creates a hybrid piezoelectrodynamic generator. In this paper, a model for this hybrid generator is proposed. The model allows the accurate simulation of the mechanical and electrical part of the generator. It also makes it possible to analyze the waveforms and phase relationships of the two electrical outputs of the hybrid generator and thus simulate power management circuits and their feedback on the generator.

Portable Electrodynamic Generator Using a Mass-Spring System Resonated by Human Walking Motion.

The authors fabricated a portable generator that can charge batteries of mobile electric devices such as cellular phones. The generator contains a coil and a permanent magnet attached to a spring. Natural frequency of the magnet-spring system is designed to be coincided with frequency of human walking motion. Resonant oscillations of the magnet produce greater voltage and power when the generator is carried by a walking human. Induced electricity is accumulated in a condenser through double charging voltage circuit. The experimental results show that average power produced by the generator on the walking human is 18.7W and voltage of the condenser exceeds 3 V.

Maximum power from electrodynamic generators

The present work, an extension of a previous study, is an attempt to estimate the maximum power available from electrodynamic generators. An analysis is made of the effect of the charge carrier mobility on the power available.