Device for controlling an asynchronous motor
CA 2098469 C · Owner: The Swatch Group Management Services Ag · Inventors: Jeanneret, Rene
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention concerns a control device for an asynchronous motor, notably intended for the drive system of an electric vehicle. This control device comprises electric supply means able to produce an AC supply voltage whose frequency (FAL) and amplitude (UAL) may be adjusted independently of one another. For a given frequency of the supply voltage, the amplitude of this voltage is able to vary between a minimum value and a maximum value, the difference between the frequency of rotation of the turning magnetic field in the vicinity of the motor and the frequency of rotation of the rotor being maintained substantially constant as long as the amplitude of the supply voltage is less …
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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 15, 1993 and granted August 13, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 15, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 15, 2015.
- 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.