A novel circuit for power factor and lamp efficiency
CA 2201653 C · Owner: Raytheon Company · Inventors: Deavenport, Joe E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A gas discharge lamp electronic ballast circuit including a gas discharge lamp (51); a rectifier circuit (11a, 11b, 11c, 11d, 13) responsive to CA power for providing a full wave rectified sinewave voltage across output terminals of the rectifier circuit; a transformer (T1) having a primary winding and a secondary winding; a switching circuit (29) for repetitively connecting the rectifying circuit full wave rectified sinewave voltage to the primary winding; a driving circuit (33 35, 37, T2, 49), responsive to the secondary winding for driving the lamp with a sinusoidal voltage having a predetermined frequency; a current sensing circuit (39, 41, 45, 47 43) for sensing, an average of peaks of …
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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 April 3, 1997 and granted March 14, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 3, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 3, 2019.
- 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.