Patent ID: 11877126
Assignee: GOOGLE LLC
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. An audio speaker system comprising:
a frame having a surface extending in a plane;
a flexible printed circuit (FPC) coupled to the surface of the frame, wherein the FPC includes a sense coil;
a magnet;
a voice coil defining an axis extending in a first direction non-parallel to the plane and positioned in a magnetic field of the magnet, the voice coil being configured to oscillate along the first direction when the voice coil is energized; and
an excursion measuring system configured to perform operations comprising:
determining an electrical parameter of current flow in the sense coil; and
based on the electrical parameter, determining a distance between the voice coil and the sense coil in the first direction.