Low distortion line dimmer and dimming ballast
CA 2328270 C · Owner: Osram Sylvania Inc. · Inventors: Liu, Guang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A line dimmer has a limited maximum firing angle to limit a total harmonic distortion within a powering signal. A dimming ballast generates a pulse width modulated signal based on a firing angle of the powering signal generates a dimming command signal based on the pulse width modulated signal and dims a lamp based on the dimming command signal. The maximum firing angle may be limited to 30 degrees 25 degrees, or 20 degrees, for example to limit a resulting total harmonic distortion.
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 December 11, 2000 and granted November 29, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 11, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 11, 2022.
- 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.