Self-Regulating Class E Resonant Power Converter Maintaining Operation in a Minimal Loss Region

A self-regulating Class E/resonant power converter includes a power switching device which is gated on at each transition between negative and positive half cycles of the load current by drive signals generated by a drive circuit, the rate at which the drive signals are generated being controlled by a zero crossing detector which monitors the load current and adjusts the frequency of the drive signals in correspondence with changes in the time between successive negative-to-positive zero crossings of the load current such that the power switching device continues to be switched on at substantially zero voltage, zero slope conditions to maintain the power converter operating at the optimal Class E frequency.Sponsorship: Illinois Institute of TechnologyUnited States Paten

Suspended Carrier Modulation of High-Q Transmitters

A method for on-off modulation of a transmitter coil current of a high-Q resonant circuit transmitter comprising the steps of sensing a zero-crossing of the transmitter coil current and substantially instantaneously interrupting the transmitter coil current, and a high-Q resonant circuit transmitter for carrying out said method.Sponsorship: Illinois Institute of TechnologySponsorship: United States of America as represented by the Department of Health and Human ServicesUnited States Paten

A floating metal microelectrode array for chronic implantation

Implantation of multi-electrode arrays is becoming increasingly more prevalent within the neuroscience research community and has become important for clinical applications. Many of these studies have been directed towards the development of sensory and motor prosthesis. Here, we present a multi-electrode system made from biocompatible material that is electrically and mechanically stable, and employs design features allowing flexibility in the geometric layout and length of the individual electrodes within the array. We also employ recent advances in laser machining of thin ceramic substrates, application of ultra-fine line gold conductors to ceramic, fabrication of extremely flexible cables, and fine wire management techniques associated with juxtaposing metal microelectrodes within a few hundred microns of each other in the development of a floating multi-electrode array (FMA). We implanted the FMA in rats and show that the FMA is capable of recording both spikes and local field potentials