Photoelectric combustion products detector with low power consumption and improved noise immunity
CA 1236196 A · Owner: Pittway Corporation · Inventors: Keeler, Manley S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A photoelectric combustion products detector for periodically sampling the ambient air includes sampling means capacitively coupled to an AC source so that the, coupling capacitor produces at the sampling means a source current 90° out of phase with the AC source voltage, which is rectified to provide a supply voltage. Sampling is controlled by a NAND gate having at its inputs a varying threshold level which is proportional to and in phase with the supply voltage. A ramp signal generator connected to one gate input terminal enables the gate when the ramp signal exceeds the varying threshold level. The other input terminal of the gate is connected to a timing circuit comprising a Zener …
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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 May 3, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 3, 2005.
- 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.