Resonant inductive coupling

About: Resonant inductive coupling is a research topic. Over the lifetime, 1034 publications have been published within this topic receiving 21101 citations. The topic is also known as: Magnetic phase synchronous coupling.

Magnetic Resonant Coupling As a Potential Means for Wireless Power Transfer to Multiple Small Receivers

Abstract: Wireless power transfer via magnetic resonant coupling is experimentally demonstrated in a system with a large source coil and either one or two small receivers. Resonance between source and load coils is achieved with lumped capacitors terminating the coils. A circuit model is developed to describe the system with a single receiver, and extended to describe the system with two receivers. With parameter values chosen to obtain good fits, the circuit models yield transfer frequency responses that are in good agreement with experimental measurements over a range of frequencies that span the resonance. Resonant frequency splitting is observed experimentally and described theoretically for the multiple receiver system. In the single receiver system at resonance, more than 50% of the power that is supplied by the actual source is delivered to the load. In a multiple receiver system, a means for tracking frequency shifts and continuously retuning the lumped capacitances that terminate each receiver coil so as to maximize efficiency is a key issue for future work.

Resonant intermolecular transfer of vibrational energy in liquid water

Abstract: Many biological, chemical and physical processes involve the transfer of energy. In the case of electronic excitations, transfer between molecules is rapid, whereas for vibrations in the condensed phase, resonant energy transfer is an unlikely process because the typical timescale of vibrational relaxation (a few picoseconds) is much shorter than that of resonant intermolecular vibrational energy transfer1,2. For the OH-stretch vibration in liquid water, which is of particular importance due to its coupling to the hydrogen bond, extensive investigations have shown that vibrational relaxation takes place with a time constant of 740 ± 25 femtoseconds (ref. 7). So for resonant intermolecular energy transfer to occur in liquid water, the interaction between the OH-stretch modes of different water molecules needs to be extremely strong. Here we report time-resolved pump-probe laser spectroscopy measurements that reveal the occurrence of fast resonant intermolecular transfer of OH-stretch excitations over many water molecules before the excitation energy is dissipated. We find that the transfer process is mediated by dipole–dipole interactions (the Forster transfer mechanism9) and additional mechanisms that are possibly based on intermolecular anharmonic interactions involving hydrogen bonds. Our findings suggest that liquid water may play an important role in transporting vibrational energy between OH groups located on either different biomolecules or along extended biological structures. OH groups in a hydrophobic environment should accordingly be able to remain in a vibrationally excited state longer than OH groups in a hydrophilic environment.

Wireless power transmission for electronic devices

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power receiver includes a receive antenna for coupling with a transmit antenna of transmitter generating a magnetic near field. The receive antenna receives wireless power from the magnetic near field and includes a resonant tank and a parasitic resonant tank wirelessly coupled to the resonant tank. A wireless power transmitter includes a transmit antenna for coupling with a receive antenna of a receiver. The transmit antenna generates a magnetic near field for transmission of wireless power and includes a resonant tank and a parasitic resonant tank coupled to the resonant tank.

Inductive power distribution system

Abstract: A contactless inductive power distribution system operating at 10 KHz has a self tuning resonant power supply connected to a resonant primary conductive path (10110, 10111) comprising a pair of parallel litz wire conductors (10110, 10111) each encapsulated within an insulated sheath and supported on a structural monorail beam (10101) on which a plurality of electric vehicles can run. Each vehicle has an electric motor (not shown) capable of deriving power from a resonant pick-up coil (10115) wound on a ferrite core (10102) mounted on the vehicle in close proximity to the primary conductors (10110, 10111). Each vehicle also has switching means (10116) capable of preventing a lightly loaded vehicle from presenting a reduced load to the resonant primary. As shown, this comprises an isolating coil (10116) having a switch (not shown) to switch the coil between an open circuit and a short circuit, so that when the switch is switched from one state to another state the power coupled between the primary conductive path (10110, 10111) and the pick-up coil (10115) is changed.