Class 'd' audio speaker amplifier circuit with state variable feedback control
CA 2124976 A1 · Owner: Mistry, Yogi L. · Inventors: Wagner, Randall M.; Mistry, Yogi L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An audio amplifier for telephone-sourced audio signals that drive paging speaker employs 21 class D amplifier and a state variable feedback network which monitors voltage and current levels of an audio output filter to which the paging speakers are coupled so as to adjust the operation of the amplifier circuit, to compensate variations in the speaker loading of the audio output filter. The class D amplifier includes a pulse width modulator, which control the switching of a power Hbridge-configured switching circuit. The switching circuit sources and sinks current with respect lo the paging speaker load. The output of the power bridge switching circuit is a high energy square wave-type …
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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 June 2, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 2, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 2, 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.