Ballast circuit for high intensity discharge lamps
CA 2344408 C · Owner: Perkinelmer, Inc. · Inventors: Lau, Lake
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A ballast circuit for a high intensity discharge lamp (24) includes a boost converter (16), a boost controller (36) responsive to the boosted dc output , voltage for driving the boost converter (16) to maintain the boosted output voltage at a predetermined level; a buck converter (18); and a buck controller (38) for driving the buck converter to operate the lamp in a transition mode and maintaining the reduced dc output voltage at a preselected level for operating the lamp in a steady mode.
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 September 14, 1999 and granted December 9, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 14, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 14, 2021.
- 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.