Granted Patent
Utility
US 5,374,874 · App. 07/408,270
Electronic ballast with crest factor control
Inventor:
Ole K. Nilssen
Patented Case
View Patent ↗
Granted: Dec 20, 1994
Filed: Sep 18, 1989
Inventor
Ole K. Nilssen
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.