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:
Feb. 18, 2003
Filed:
Jun. 14, 2001
Stephen P. DeOrnellas, Santa Rosa, CA (US);
Robert A. Ditizio, Petaluma, CA (US);
Tegal Corporation, Petaluma, CA (US);
Abstract
A rotary transformer includes a resonant circuit and a coil drive circuit. The resonant circuit includes a resonating capacitor connected to a power MOS transistor, coupled across the primary coil of the transformer. The coil drive circuit includes a diode connected to a power MOS transistor coupled across the primary coil of the transformer. A microprocessor detects changes in the voltage across the primary coil. The resonant circuit is connected and disconnected from the transformer during a power transfer mode and a data transfer mode, respectively. During the power transfer mode, stored energy in the leakage inductance of the primary coil is used for power coupling, via the resonant circuit, instead of being dissipated as heat. The resonant circuit is disconnected from the rotary transformer during the data transfer mode to maximize bandwidth for two-way data transfer between the primary and secondary sides of the transformer. The transformer uses a synchronous mode of operation in which the power MOS transistor of the coil drive circuit is turned on when the voltage across the primary coil changes from a positive to a negative value during the power transfer mode. The synchronous mode of operation virtually eliminates a current spike through the diode of the coil drive circuit and provides the microprocessor an appropriate amount of time to recognize the voltage changes across the primary coil.