Differential Drive Amplifier for Noise-Free Wireless Power
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Summary
Problems
Long-range and alignment-insensitive wireless power systems face challenges with high levels of conducted and radiated noise due to the use of high voltages and large, unshielded primary coils, leading to electromagnetic interference with other electronic devices.
Innovation solutions
A differential drive amplifier and coil arrangement that generates equal but opposite voltage signals, which are co-located to cancel out common-mode noise, reducing interference while maintaining efficient wireless power transfer.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If high voltages and large primary coils are used in wireless power systems, then power transfer capability and operating range are improved, but common-mode noise emission and electromagnetic interference increase
Why choose this principle:
The patent applies differential signaling to convert the harmful common-mode noise into beneficial differential-mode signals. By driving the primary coil with equal and opposite voltage signals, the system maintains the high voltage necessary for power transfer while the differential configuration causes common-mode noise to cancel out at distant points, transforming the noise problem into a solution.
Principle concept:
If high voltages and large primary coils are used in wireless power systems, then power transfer capability and operating range are improved, but common-mode noise emission and electromagnetic interference increase
Why choose this principle:
The patent introduces asymmetry in the voltage distribution across the primary coil windings by applying differential voltages with opposite polarities. This asymmetric voltage arrangement ensures that while each winding experiences high voltage, the net common-mode voltage radiated to the environment is minimized, resolving the contradiction between power capability and noise emission.
Application Domain
Data Source
AI summary:
A differential drive amplifier and coil arrangement that generates equal but opposite voltage signals, which are co-located to cancel out common-mode noise, reducing interference while maintaining efficient wireless power transfer.
Abstract
An apparatus to wirelessly output power at a level sufficient to power or charge a receiver device comprising a first coil driven by a first signal; and a second coil driven by a second signal, the first and second signals substantially equal in magnitude and opposite in polarity, the first coil and the second coil having a spiral configuration within a common plane that provides for co-location of substantially equal and opposite voltages within the first and second coils respectively, at substantially any location on the common plane.