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:
Sep. 02, 2003
Filed:
Oct. 25, 2001
Phillip Ryan Wagner, Baltimore, OH (US);
John Gilman Chapman, Jr., Delaware, OH (US);
Ranco Incorporated of Delaware, Wilmington, DE (US);
Abstract
A microcontroller ( ) uses a two-stage algorithm to sample the state of an AC switch ( ) connected directly to an input pin ( ). An AC line signal ( ) is sampled by a pre-filtering routine that samples the AC line signal ( ) to determine when a peak or trough is occurring and generates a trigger signal at or near the occurrence of a peak or trough. By basing the triggering signal on the state of the AC line signal ( ), the triggering signal is independent of any shift of the phase angle of the AC line signal ( ) and the microcontroller's operating clock ( ). A switch sampling routine ( ) is initiated at each occurrence of the triggering signal which samples the state of the AC switch ( ). Successive sampled values are shifted into a shift register ( ) on the microcontroller ( ). Another routine ( ) is periodically initiated by the functional software of the microcontroller ( ) to update a flag, indicating the status of the AC switch ( ), based on the contents of the shift register ( ).