Method and apparatus for controlling a single-or polyphase a.c. controller
CA 2008127 C · Owner: Doerwald, B. Claus · Inventors: Runggaldier, Diethard; Doerwald, B. Claus
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for controlling single or polyphase a.c. power controllers when controlling a.c. power controllers by means of phase angle control of semiconductor switches, the firing signals on the one hand must be long enough to guarantee a reliable firing and on the other hand, be short enough to prevent an overloading of ignition amplifiers. According to the invention therefore the use of, firing signals with variable temporal lengths is provided which end at least approximately at the reincrease of the current flowing in the phase that has been fired. Moreover devices for implementing the method are specified.
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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 January 19, 1990 and granted December 23, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 19, 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.