Adjustable frequency drive
CA 1189902 A · Owner: Vee Arc Corporation · Inventors: Hickman, Mark R.; Brown, Michael M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A circuit for driving a power transistor that forms a part of an inverter circuit used in motor control in which the circuit is switched at high voltages. The motor drive circuit isolates and amplifies a control signal so as to operate the power switching transistors. The base drive circuit employs two characteristics of power transistors to derive maximum protection and maximum performance simultaneously. This control is accomplished by sensing both the collector-to-emitter voltage of the power transistor as well as the base-to-emitter voltage thereof. In an alternate embodiment described herein, a feedback circuit is also provided sensitive to collector-to-emitter voltage for shortening …
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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 July 2, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 2, 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.