Inductev, Inc.

John M Wolgemuth

Benjamin H Cohen

Daniel S Hackman

Andrew William Daga

Francis J McMahon

Bruce Richard Long

Peter C Schrafel

Moses M Keener

Anthony W Calabro

Francis J Mcmahon

Andrew W Daga

A current sensing method measures a fractional current through a coil having a plurality of coil windings by using a current sensing resistor to measure a current through a subset of the plurality of coil windings and using a voltage sensor to measure a voltage drop across the current sensing resistor. The measured current and voltage values are provided to a processor to determine the fractional current and phase of the coil. For example, the fractional current and phase of the coil may be determined by calculating a total current of the coil as I=n(V/Rx), where n is the number of coil windings of the coil, V is the measured voltage, and Rx is the impedance of the current sensing resistor. The coil may be a secondary winding used in a wireless power transfer system.

Current sensing in a wireless power transfer system

A thin resonant induction wireless power transmission transfer coil assembly designed for low loss and ease of manufacturing includes one or more printed circuit boards having a first conductor pattern wound in a spiral on a first side and a second conductor pattern wound in a spiral on a second side thereof, where the second conductor pattern is aligned with the first conductor pattern whereby the second conductor pattern reinforces magnetic flux generated by the first conductor pattern. The first and second conductor patterns are placed relative to one another so as to provide flux transmission in a same direction. One or more of such printed circuit boards form a wireless power transmission coil assembly with a conductive winding layer, a ferrite flux diversion layer, conformal spacing layers, an eddy current shield layer and an assembly enclosure.

Wireless power transfer thin profile coil assembly

A magnetic inductive resonance charging circuit includes a resonant network having an inductive secondary coil that converts a magnetic field received from an inductive primary coil into an alternating current (AC) signal and a synchronous rectifier that rectifies the AC signal to generate a direct current (DC) signal for application to a load. The synchronous rectifier includes a variety of configurations for shunting the AC waveform of an AC current source in the event of a fault. For example, a rectifier controller may hold a pair of normally open switches of the rectifier off and a pair of normally closed switches of the rectifier on to shunt the AC current source when an over-voltage, over-current fault condition or an over-temperature fault condition is detected. Configurations are provided for grounding the capacitive electromagnetic interference produced in the chassis of an electric vehicle when the resonant network is unbalanced.

Failsafe safety circuits for protection from faults or loss of rectification control during wireless power transfer

A traffic queue having at least one charging lane including a plurality of ground-side wireless charging assemblies installed in the ground and spaced to permit at least two vehicles to be simultaneously charged by wireless power transfer is used to charge electric vehicles. During charging, the vehicle is aligned with a first ground-side wireless charging assembly in the at least one charging lane and charged using the first ground-side wireless charging assembly in a first charging session. The vehicle is then advanced to a second ground-side wireless charging assembly and aligned with the second ground-side wireless charging assembly and charged using the second ground-side wireless charging assembly in a second charging session. A time-ordered sequence of messaging is provided between the first and second ground-side wireless charging assemblies and a vehicle-side wireless charging assembly to control providing power and billing for the first and second charging sessions.

Opportunity charging of queued electric vehicles

A charging system for charging a battery includes a rectifier that rectifies power received from an AC power source into a DC signal for charging the battery and an arc detection circuit that measures noise added to the DC signal and generates a measured noise signal. A processor analyzes the measured noise signal to detect a series-arc and, when a series-arc is detected, causes a shunt of the AC current of the rectifier for a period of time to reduce a DC output of the rectifier toward zero. A passive arc detection circuit is inserted between the rectifier and the battery and includes a filter capacitor and a sense resistor in parallel with a smoothing capacitor. A voltage across the sense resistor is amplified, digitized, and outputted as the measured noise signal. The DC signal may be scanned to obtain the measured noise signal in different frequency windows.

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Chester Springs, PA, United States of America

John M Wolgemuth