P.t.c. resistor sensor circuit
CA 2129887 C · Owner: Holmes, William W. · Inventors: Holmes, William W.; Markum, Randall; Stoops, John C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Electrical heating apparatus (10) is used in an electric stove (R) having a glass/ceramic cooking surface (S). A pan (12) is mounted adjacent an underside of the cooking surface. An electrical heating element (20) installed in the pan heats a defined area (A) of the cooking surface when electrical current is applied to the element. A sensor (34) installed in direct contact with the cooking surface senses the temperature of the cooking area. A control unit (42), to which an output of the sensor is supplied, is responsive to the output to control current flow to the heating element. This allows the apparatus to respond to temperature changes at the cooking area to insure food is properly …
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 August 10, 1994 and granted May 25, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 10, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 10, 2016.
- 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.