The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 05, 1999
Filed:
Aug. 29, 1997
James Stuart Baughman, Deford, MI (US);
Kevin C Ross, Hemlock, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An apparatus for transferring power and communication data across an annular gap comprises an inductively-coupled primary coil winding and secondary coil winding rotatable therein. Two signal oscillators are electrically coupled to a transistor for controlling current flow through the primary coil winding, thereby inducing a signal with a respective frequency in the secondary coil winding. An electronic switch operates so as to apply one of the two signals to the transistor for charging a capacitor coupled to the secondary coil winding, and operates so as to apply the other of the two signals to the transistor for discharging the capacitor. Actuation of control devices operate so as to modulate the impedance of the secondary coil winding. The inductive coupling of the two coil windings results in this modulation being mirrored by a modulation of the voltage developed across the primary coil winding. The primary coil winding voltage is compared to a threshold voltage for decoding the modulated voltage and determining actuation of the control devices.