Diagnostic input for programmable logic controller
CA 2267240 C · Owner: Siemens Energy & Automation, Inc. · Inventors: Clark, Karen R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An input device for a Programmable Logic Controller is taught. Briefly stated an incoming input voltage is rectified with an input impedance being principally capacitive in order to avoid heat dissipation. This rectified power in turn cooperates with a current source such that once a set point is reached the current source current does not increase with increasing input voltage. The current source is also utilized to prevent off-state leakage current from turning on an input optocoupler by allowing most of the input current to be drawn through the current source until a turn-on threshold which is set by a zener diode is met.
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 September 16, 1997 and granted June 5, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 16, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 16, 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.