Telecommunication subscriber line access circuit with ground key

Details Telecommunication subscriber line access circuit with ground key Telecommunication subscriber line access circuit with ground key

1980-03-06

1981-11-17

Robinson, Thomas A.

H04G 136

Patent

active

043013341

ABSTRACT:
A subscriber line access circuit for use in a telecommunications system is disclosed. The subscriber line access circuit has a power supply bridge in the form of a first resistor inserted in the b-wire (ground potential side) of a subscriber line, a second resistor inserted in the a-wire (supply potential side) of the subscriber line, and a capacitor which bridges the two wires at the terminals of the two resistors on the sides thereof opposite to the respective potential sources. This supply bridge is coupled on the capacitor side with a two-to-four wire hybrid transformer for the two-wire/four-wire transition to the system, and includes an evaluating circuit which delivers an indicating signal when the subscriber actuates a ground key. A cutoff circuit is arranged in the power supply bridge in series with the first or the second resistor, or both, between such resistor and the winding of the hybrid transformer to which it, the resistor, as well as the evaluating circuit are connected. This cutoff circuit comprises a cutoff switch which is opened, with a delay, upon ground key actuation and closed when the ground key actuation is terminated.

REFERENCES:
patent: 3121775 (1964-02-01), Amory et al.
patent: 3715511 (1973-02-01), Shaffer

Affiliated with

Also associated with

Rating

Telecommunication subscriber line access circuit with ground key does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Telecommunication subscriber line access circuit with ground key, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Telecommunication subscriber line access circuit with ground key will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1293808