Bugging proof apparatus
CA 2098027 A1 · Owner: Lu, Chuen-Lin · Inventors: Lu, Chuen-Lin; Lu, Chuen-Lin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a bugging proof apparatus and in particular to one including: a micro-computer having a watch dog timer (WDT) and a sleep device and monitoring a telephone line once per second; a 30-volt detecting circuit composed of a 30-volt zener diode and a NPN transistor and connected with said micro-computer so that when the voltage is higher than 30 volts said, transistor will be conducted and will transmit a low potential signal to said micro-computer; a 1-volt detecting circuit including a silicon diode and a NPN transistor and connected with said micro-computer so that when the voltage is higher than 1 volt said transistor will, be conducted and will transmit a low …
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 June 9, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 9, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 9, 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.