Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
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
Stacked type semiconductor memory device and chip selection circuit
System and method of automatic piloting for in-flight refuelling of aircraft, and aircraft comprising said system
Randomly accessible visual information recording medium and recording method, and reproducing device and reproducing method
Azole derivatives, methods for producing the same, intermediate thereof, agro-horticultural agents
Motor drive component verification system and method
Modulation of TIM receptor activity in combination with cytoreductive therapy
Magnetic disk and manufacturing method thereof
  Randomly Featured Patents
Feedback control for multicast or broadcast services
Impregnated cloth
Imaging methods and apparatus particularly useful for two and three-dimensional angiography
Begonia plant named `BRXPE11`
De-immunized streptokinase
Hydrodynamic bearing spindle motor
Process for isolation of proteins using food grade salt solutions at specified pH and ionic strength
Semiconductor device having vertical transistor, manufacturing method thereof, and data processing system
Circuit breaker lockout
Spherical lng-tank and a production method for such a tank