Improvements relating to current indicators
CA 2309064 A1 · Owner: Gardner, Robert · Inventors: Gardner, Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A current detector/indicator for DC has a transistor (1) and an LED (2). They are arranged so that current flow through the LED causes the transistor to conduct, shunting excess current away from the LED and through the transistor. For AC, the circuit can be doubled, with transistors and LEDs arranged with inverse polarity. A triac (15) may supplant the two transistors with , parallel, opposed LEDs (16) in its gate circuit.
Read the whole patent
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 November 4, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 4, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 4, 2020.
- 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.