US 6,546,100 B1 · Load coil device

Abstract

A load coil device for a twisted pair telephone line is disclosed. The device is for compensating distributed stray capacitance in telephone lines that are longer the 18,000 feet. Typically, a load coil device would be inserted in the line every 6,000 feet. The device includes two windings, each winding to be connected in series with one of the conductors of the telephone line. The windings flatten the frequency response of the line in the voice frequency (VF) band. The device further has a capacitor connected in parallel across each winding. The values of the capacitors are chosen to provide a low impedance path that bypasses the windings for frequencies in the range of 20 kHz to 1.1 MHz. The device is particularly useful for long telephone lines over which high speed services such as asynchronous digital subscriber line (ADSL) are to be provided.

Claims7

Dependent claims

A load coil device for a two-conductor transmission line comprising:

a first winding for connecting in series with one of the two conductors of the transmission line;
a second winding for connecting in series with the other of the two conductors of the transmission line;
and
means for providing a low impedance path for high frequency signals around the first and second windings, including a first capacitor connected in parallel with the first winding and a second capacitor connected in parallel with the second winding,
said first and second capacitors each having a capacitance in the range of 50 nF to 200 nF and said first and second windings each having an inductance in the range of 2.5 mH to 10 mH.

2 more elements

Dependencies are inferred from the claim text.

Load coil device

Life of this patent

Load coil device

Life of this patent

Abstract

Claims7