Protection circuit in inverter for refrigerators
CA 2062189 C · Owner: Tecumseh Products Company · Inventors: Farr, James B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is an inverter for a portable refrigerator . The inverter includes a square wave generator operable by a DC voltage source . A timer is also, included which in conjunction with the square, wave generator provides a multiple phase waveform, for operating a compressor motor . For conventional three winding compressor motors the, inverter provides a six-step waveform for operation of the portable refrigerator. The inverter can also drive the motor using either a first or second DC voltage level, by minor changes in the inverter and using either a wye or delta winding configuration. The inverter also includes a protection circuit which protects against locked rotor and …
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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 March 3, 1992 and granted March 25, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 3, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 3, 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.