Two-phase brushless dc motor controller
CA 2069725 C · Owner: Kruse, David L. · Inventors: Kruse, David L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Control circuits for operating a two-phase brushless do motor from a do power source are described. Control of the motor is optimized by detecting induced back EMS of the two phases to sense rotor phase position. It is common knowledge that the voltage developed across the terminals of a permanent magnet motor can be represented by a winding resistance a winding, inductance and a generated back EMF. In two-phase brushless do and permanent magnet stepping motors, the induced back EMFs of the two phases are displaced from each other by 90 electrical degrees. Thus, by detecting the back EMFs of the two phases an, accurate relative position of rotor-to-stator can be determined at any rotor …
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 May 27, 1992 and granted February 27, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 2014.
- 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.