Start-up control method and apparatus for a polyphase induction motor
CA 1210444 A · Owner: Fairford Electronics Ltd. · Inventors: Groom, David C.; Fitzpatrick, Michael; Bristow, Raymond E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Start-Up Control Method and Apparatus for a Polyphase Induction Motor, In order to minimise the initial in-rush current produced on first energisation of a polyphase induction motor (10), careful control is exercised over the firing of controlled switching means (11) connected in series with each of the supply phases (A, B, C) or motor windings. This control includes effecting an initial selective firing of the switching means (11) such as to cause current to flow between two only (B, C) of the supply phases, the firing being timed to occur such that the voltage between these two phases (B, C) is decreasing in value at the moment of firing. Thereafter, the switching means (11) are …
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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
- Granted August 26, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 26, 2003.
- 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.