Patent ID: 6650104
Filing Date: 2003-11-18
Classification: G01R

Abstract:
A device for detecting impedance disturbance points in symmetrical data transmission lines having first and second conductor strands, comprising: an evaluation unit having at least two magnetosensitive elements, one of the magnetosensitive elements being positioned in the proximity of the first conductor strand and a second one of the magnetosensitive elements being positioned in the proximity of the second conductor strand, wherein the evaluation unit comprises an evaluation circuit connected to the magnetosensitive elements which supplies a fault signal at an output terminal;wherein the evaluation circuit comprises a first differential amplifier, which supplies at its output terminal a fault signal indicating at least one of a short circuit of a conductor strand with respect to a shielding element or with respect to ground; wherein the evaluation circuit comprises a second differential amplifier, which supplies at its output terminal a fault signal indicating at least one of a short circuit between the two conductor strands or an interruption of one of the two conductor strands; wherein the first and second conductor strands run parallel to each other and the evaluation unit has a parallel connection with first, second and third signal branches, the first signal branch having a series connection of a first resistor and a second resistor, the second signal branch having a series connection of the second magnetosensitive element and a fourth resistor and the third signal branch having a series connection of the first magnetosensitive element and third resistor; and wherein a first input of the first differential amplifier is connected to the connecting point between the first magnetosensitive element and the third resistor and a second input of the first differential amplifier is connected to the connecting point between the second magnetosensitive element and the fourth resistor.