Feedback circuit and method of operating ballast resonant inverter
CA 2472530 C · Owner: Osram Sylvania Inc. · Inventors: Alexandrov, Felix I.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A ballast resonant inverter with a self-oscillating driver IC powers and dims a gas discharge lamp. A feedback circuit automatically adjusts IC oscillator frequency for safe and stable inverter operation above the resonant frequency following changes in the resonant load. The feedback signal is derived from resonant inverter output voltage by attenuating, programmed phase shifting and injecting the resulting signal in a timing circuit of the IC. The feedback circuit includes an active inverter circuit or passive RC phase boosting networks coupled in series. Phase control of the feedback signal by variable RC networks is used in transient modes of ballast-lamp operations.
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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 June 25, 2004 and granted August 5, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 25, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 25, 2026.
- 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
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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.