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US 4,394,616 AGranted
Cable break locator
AssigneeGeosource Inc.
InventorsEdward M. Browne, Miles A. Smither
Life of this patent
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Abstract
Method and apparatus for determining the location of a break in a pair of wires of a multi-wire cable are disclosed. The method and apparatus permit such breaks to be found with a high degree of accuracy. The method and apparatus are especially useful in connection with locating breaks in seismic cables.
Claims8
A method of determining the location of a break in a given pair of wires in a multi-pair cable, comprising the steps of:
- (a) shorting one wire of the given pair and all other wires in the cable to ground;
- (b) applying a variable frequency AC current source across the given pair to develop an AC voltage across the given pair;
- (c) multiplying the AC voltage developed across the given pair by a second AC signal, which has a quadrature phase relationship to the AC current source to form a product signal having a DC component proportional to the quadrature component of the AC voltage across the given pair;
- and
- (d) comparing the DC component of said product signal to a reference signal, said reference signal having a value which is inversely proportional to the capacitance of an unbroken pair.
2 more elements
Apparatus for determining the location of a break in a given pair of a multi-pair cable, which comprises:
- means for shorting one wire of the given pair and all other wires in the cable to ground;
- a variable frequency AC current source which is connected across the wires of the given pair to produce an AC voltage across the given pair;
- a multiplier for multiplying the voltage produced across the given pair by a second AC signal, which is in a quadrature phase relationship to the AC current source to form a product signal;
- and
- means for comparing the DC component of the product signal to a reference signal, said reference signal having a value which is inversely proportional to the capacitance of an unbroken pair.
2 more elements
Dependencies are inferred from the claim text.