Power control circuit for discharge lamp and method of operating the same
CA 2004334 C · Owner: General Electric Company · Inventors: Nerone, Louis Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Circuit, and methods of using the same are, disclosed for controlling the power supplied to a discharge lamp of the type having a closed inductive loop, such as the resonant ballast circuit for a fluorescent lamp or the inductive ballast loop of a high pressure sodium lamp, wherein the closed inductive loop is operated by an electrical power supply having a d-c input stage and an output power controlled by the switching frequency of a switch means within the power supply itself whereby current flows to the closed inductive loop when the switch means is conductive and no current flows from the power supply to the closed loop when the switch means is non-conductive. This power control circuit …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 30, 1989 and granted January 25, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 30, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2011.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.