Low leakage proximity switch
CA 1264835 C · Owner: Square D. Company · Inventors: Harris, Geoffrey J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The circuit operates a main switch TH1 to pass an A.C. supply through an external load when a metallic object is in proximity to a coil L1 driven by an oscillator circuit which is, connected to a level detector circuit controlling TH1. The circuit is powered by a power supply stage including a storage capacitor C7, the charging current thereof being controlled by a transistor T10 and MOSFET T11. Upon initial application of the A.C. supply, the level detector circuit is overridden by a circuit including capacitor C3 and transistor T4 until a predetermined period of time has elapsed, so as to prevent the generation of erroneous "on" signals before the oscillator has stabilised.
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
- Granted January 23, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 23, 2007.
- 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.