US 4,377,782 A · Fault location methods and apparatus using current pulse injection

Abstract

A probe for sensing direction of flow of an injected current pulse along a conductor of a circuit under test is linked to an ATE, to be triggered to inject the pulse during a test sequence at a step previously found by the ATE to establish a faulty state in the circuit. Thus, the faulty one of several components connected to a circuit node can be identified. The probe itself can also be used independently, and injects an approximately triangular-waveform current pulse which has a steep rising edge and a less steep falling edge, thereby inducing a voltage pulse which is asymmetric about the zero voltage level and thus permits discrimination of the direction of current flow. The probe may have a single current injection contact disposed between the limbs of a bifurcated core for the pick-up coil.

Claims10

Dependent claims

A method of testing a powered electronic circuit, the method comprising:

applying a sequence of test signals to said circuit;
storing, in response to the detection of a fault in said circuit during the application of said sequence of test signals, the number of the step in said sequence at which the fault occurred;
repeating the application of said sequence of test signals to the circuit while applying triggerable current pulse applying means to a conductor of the circuit associated with the fault;
automatically triggering said current pulse applying means to apply a current pulse of predetermined sense to said conductor when said sequence reaches the step whose number was stored;
and
determining the direction of flow of said current pulse along the conductor, whereby to permit the determination of the direction of the fault with respect to the point on the conductor at which the pulse is applied.

3 more elements

Apparatus for testing a powered electronic circuit, the apparatus comprising:

means for applying a sequence of test signals to said circuit;
means for storing, in response to the detection of a fault in said circuit during the application of said sequence of test signals, the number of the step in said sequence at which the fault occurred;
triggerable means for applying a current pulse of predetermined sense to a conductor of the circuit associated with the fault;
triggering means responsive to said test signal applying means and said storing means and coupled to the current pulse applying means to trigger the application of such a pulse when said sequence, during a subsequent application thereof to the circuit, reaches the step whose number was stored;
and
means responsive to said triggering means and arranged to determine the direction of flow of said current pulse along the conductor, whereby to permit the determination of the direction of the fault with respect to the point on the conductor at which the pulse is applied.

3 more elements

Dependencies are inferred from the claim text.

Fault location methods and apparatus using current pulse injection

Life of this patent

Fault location methods and apparatus using current pulse injection

Life of this patent

Abstract

Claims10