US 5,329,588 AGranted

Telecommunication line circuit

AssigneeAlcatel N. V.

InventorsEddie L. M. Willocx, Elve D. J. Moons

Life of this patent

Estimating the term…

Loading patent…

Abstract

Each line wire is separately biassed by DC potentials feeding Inputs of the respective line wire driver amplifiers, the first potential (BA) being nearer ground and the second at an equal distance from the negative supply used to power the amplifiers so as to allow a suitable AC swing for the speech and metering signals also feeding the inputs of the amplifiers. The second potential (BB) is obtained from a DC synthesizing loop voltage and to which is added (OA6) the first potential, both potentials being also combined (OA5) to control a switched mode DC/DC converter delivering the negative power supply. In addition to both potentials being filtered with reference to ground, another measure reducing noise relies on AC signals push-pull outputs driving the amplifier inputs, also in push-pull through four resistances.

Claims15

Dependent claims

Telecommunication line circuit including a DC loop resistance synthesizing circuit, said line circuit comprising:

a Herter bridge,
two line wires coupled to the Herter bridge,
two line amplifiers for providing a synthesized feed voltage across the two line wires, a synthesized resistance in each said line wire, and a distinct line potential for each said line wire,
a sense amplifier coupled to the Herter bridge for producing a sense voltage proportional to a current flowing in the line wires,
bias means responsive to the sense voltage for providing a distinct respective bias voltage for each of the two line amplifiers,
battery means for supplying a battery supply voltage, and
a converter responsive to the bias means for converting the battery supply voltage to a common supply voltage for the two line amplifiers which is a combination of the two respective said distinct bias voltages.

4 more elements

Dependencies are inferred from the claim text.