Constant current circuit and an oscillating circuit controlled by the same
CA 2052248 C · Owner: Inoue, Shuichi · Inventors: Suwada, Makoto; Inoue, Shuichi; Usui, Yuzo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed are a constant current circuit which provides an output current I2 which varies with changes of power source voltage Vcc, and an oscillating circuit whose oscillation frequency varies with changes of I2 in the constant current circuit. The constant current circuit comprises bipolar transistors coupled to form a differential amplifier wherein one of the, transistors is supplied with a reference voltage and another is supplied with a divided voltage of Vcc and a resistor connecting, the emitters of the transistors is provided for controlling the slope of the Vcc-I2 characteristic curve of the constant current circuit. The oscillating circuit comprises a capacitor charged with I2 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 September 25, 1991 and granted July 26, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 25, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 25, 2013.
- 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
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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.