Fluorescent tube heating and starting circuit
CA 2067196 C · Owner: Deutsche Thomson-Brandt Gmbh · Inventors: Roth, Harald
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A circuit, having a split primary transformer for controlling the warm-up, ignition and normal operating stages of a fluorescent tube initially applies in phase voltages to opposite sides of the split primary transformer during a warm-up stage; during an ignition stage and during the normal tube operation out of phase voltage , waveforms are applied to opposite sides of the split primary of the transformer.
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 October 16, 1990 and granted June 6, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 16, 2012.
- 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.