Electronic switches
CA 2104801 C · Owner: Northern Telecom Limited · Inventors: Shtulman, Alexander J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electronic switch is disclosed for switching relatively high voltages such as, telecommunications voltages of the order of -48 volts in response to logic levels of, typically 0 to 5 volts. The switch comprises a MOSFET having a source-drain switching path and a gate; a control transistor controlled from a logic level control terminal; and a potential divider MOSFET source and the control transistor and having a tapping point coupled to the MOSFET gate. The potential divider includes a zener diode and/or a resistor connected between the MOSFET source and gate. The switch can be used with a current sensing resistor and a monostable circuit to form an automatically-reset circuit interrupter …
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 August 25, 1993 and granted January 12, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 25, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 25, 2015.
- 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.