Ballast
CA 2257640 A1 · Owner: Koninklijke Philips Electronics N.V. · Inventors: Gradzki, Pawel M.; Janczak, Jerzy
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A dimming interface for translating the conduction pulse width of a signal produced by a triac dimmer into a proportional rectified average voltage serving as a dimming signal. The dimming signal is supplied as an input to an IC driver in controlling the level of lamp illumination. The proportional rectified average voltage can be converted into a signal representing a duty cycle whereby variation in the main line voltage does not affect the dimming signal.
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 March 23, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 23, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 23, 2020.
- 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.