Resources Contact Us Home
Over-current verifier circuit for an enhanced subscriber line interface

Image Number 4 for United States Patent #5163090.

An over-current verifier circuit used in a Subscriber Line Interface Circuit (SLIC) for validating an over-current condition on a subscriber loop comprising a first counter connected to the SLIC disposed to receive an oversense signal from the SLIC. The first counter begins counting when the oversense signal is received and produces an output signal when the oversense signal is still active after the counter finishes, denoting a dc over-current in the subscriber loop. A timer circuit connected to the SLIC also receives the oversense signal. The timer is arranged to begin counting when the oversense signal is received. A second counter further receives the oversense signal and is advanced by one count on the high to low transition of the oversense signal. The second counter produces an output signal when three counter advances are produced before the timer times out, denoting an ac over-current condition. A register circuit connected to the first counter and to the second counter is arranged to receive the first counter output signal or the second counter output signal and transmit to a logic interface an over-current signal advising a central controller that an over-current condition exists on the subscriber loop. Finally, a cut clear pulse generator connected to the register circuit and to a cut relay is also arranged to receive the over-current signal from the register circuit and produce an output pulse that enables the cut relay. The cut relay then electrically breaks the subscriber loop, isolating the SLIC from the subscriber loop.

  Recently Added Patents
Mobile terminal device capable of more effectively utilizing operation portions, conductive portion, operation detecting unit, power supply unit, and signal processing unit
Amide derivatives, process for preparation thereof and use thereof as insecticide
Bioreactor device, and method and system for fabricating tissues in the bioreactor device
Cantilevered probe detector with piezoelectric element
Secure access to customer log data in a multi-tenant environment
Fuel cell and a method of manufacturing a fuel cell
Liquid crystal display device
  Randomly Featured Patents
Dispersion of carbon nanotubes by nucleic acids
Solid-state image pickup apparatus and image pickup system
Coin counting and sorting apparatus
System for and a method of controlling access to a service available via a telecommunications terminal connected to a telecommunications network
Low leakage metal-containing cap process using oxidation
Preperforated coiled tubing
Tire with silica reinforced carcass ply and/or circumferential carcass belt of a natural rubber-rich, silica reinforcement-rich, rubber composition
Driving system with inductor pre-charging for LED systems with PWM dimming control or other loads
System and method for creating, transfering, and monitoring services in a telecommunication system
Delay circuit