Electric filter equipment
CA 1183214 A · Owner: Asea Aktiebolag · Inventors: Bergdahl, Bernt
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electric filter equipment for example an harmonic, filter in an HVDC convertor has in addition to the main filter, a low power model filter having the same frequency characteristic as the main filter. The model filter is supplied with a voltage which is a scaled-down version of the voltage appearing across the main filter. The currents in the main and model filters are sensed at corresponding places in the filters and compared If a deviation occurs between the sensed currents in the main and model filters an indicating signal is generated which indicates a deterioration in the performance of the main filter.
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
- Granted February 26, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 26, 2002.
- 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.