Granted Patent
Utility
US 4,894,766 · App. 07/275,840
Power supply frequency converter
Inventor:
William De Agro
Patented Case
View Patent ↗
Granted: Jan 16, 1990
Filed: Nov 25, 1988
Inventor
William De Agro
Assignee (at issue)
Hazeltine Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.