Stepping motor driving apparatus
CA 2019377 C · Owner: Baxter International Inc. · Inventors: Bowman, George A.; Kawahara, Masafumi; Matthews, Joseph B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A stepping motor driving apparatus includes a stepping motor and a pulse output circuit for outputting drive pulses for driving the stepping motor. A pulse generator generates further pulses which have a frequency higher than thatof the drive pulses. A gate circuit receives the drive pulses from the pulse output circuit and the further pulses from the pulse generator. The further pulses are output by the gate circuit during the high interval of each drive pulse. The stepping motor is thereby driven by pulses having a duty ratio that varies with the frequency of the further pulses.
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 June 20, 1990 and granted January 14, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 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.