An electronic ballast circuit
CA 2371527 A1 · Owner: Mccarthy, Paul · Inventors: Durkan, Thomas; Quinlan, Michael; Mccarthy, Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A driver waveform (30) for a gas discharge lamp is produced by a ballast circuit. The waveform (30) has a substantially vertical rising portion 831) forming an instantaneous, of time 10 µsecs or so between T0 and T1 transition between currents -l1 and +l1 which are at a current value less than peak currents IP. Then in a transition rise at controlled slew rate the waveform (30) rises with a straight rising portion (32) to a steady peak current IP identified by the numeral (33). The peak current IP is maintained between T2 and T3 which accounts for between 40% and 80% of the cycle time. Then at T3 decline occurs with waveform having a declining slew rate portion (34) to time T4 when …
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 May 17, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 17, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 17, 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.