Granted Patent
Utility
US 4,999,547 · App. 06/911,526
Ballast for high pressure sodium lamps having constant line and lamp wattage
Inventor:
Sidney A. Ottenstein
Patented Case
View Patent ↗
Granted: Mar 12, 1991
Filed: Sep 25, 1986
Inventor
Sidney A. Ottenstein
Assignee (at issue)
Enovation Controls, LLC
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.