Resources Contact Us Home
Subset switching means in apparatus for a key telephone system for enabling intercom substations to access trunk lines

Image Number 2 for United States Patent #4081615.

In an attachment apparatus for a key telephone system of the type which permits a plurality of intercom substations to access a trunk telephone line via a common communication circuit, a novel subset operable switching circuit is disclosed that permits each subset access to said common communication circuit only on an individual one-at-a-time basis. Transistor circuitry is provided to lock out other stations when more than one subset tries to gain access at the same time.

  Recently Added Patents
Magnetic storage apparatus
Channel marking for chip mark overflow and calibration errors
Integrated circuit packaging system with heat slug and method of manufacture thereof
Controlling ring-back tone output prior to a communication connection in mobile terminal
Blended block copolymer composition
System and method for access of user accounts on remote servers
Inhibitors of the mevalonate pathway of Streptococcus pneumoniae
  Randomly Featured Patents
Preparation of cupola flux
Information retrieval from a collection of information objects tagged with hierarchical keywords
Biosensor, iontophoretic sampling system, and methods of use thereof
Method of fabricating self-assembled electrical interconnections
Device for determining a distance range of an object
Paint for silver film protection and method
System and method of exploiting the security of a secure communication channel to secure a non-secure communication channel
Motor vehicle wheel front face
Golf cart heater