Fault powered fault indicator having timed reset
CA 2198949 C · Owner: Schweitzer Engineering Laboratories, Inc. · Inventors: Schweitzer, Edmund O. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A fault indicator is described having a winding disposed on a magnetic pole assembly. The winding delivers energy from a monitored conductor to circuitry of the fault indicator. A series-connected threshold device such as a four layer bilateral diode or a zener diode precludes a capacitor from charging during normal current flow in the monitored conductor. The series-connected threshold device, however, breaks down when a fault current flows in the monitored conductor. After break down, the fault current charges the capacitor. A shunt-connected threshold device, such as a zener diode limits, the voltage developed across the capacitor. After its charging phase, the capacitor drives a …
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 March 3, 1997 and granted July 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 3, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 3, 2019.
- 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.