US 7,030,623 B1Granted

Electrical short tracing apparatus and method

OwnerKevin Carpenterinventor

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Abstract

A vehicle testing apparatus and method which facilitates tracing and isolating of short circuits. The tester preferably provides a user-selected constant current level (i.e. 1, 3 and 6 amperes) for driving a vehicle short under test at a constant current level compatible with the circuit. Any significant changes in the conductance of the vehicle short under test are registered in response to circuit voltage changes. An annunciator is activated in response to sudden significant conductance changes (preferably conductance decreases) which exceed a threshold level. Annunciation (preferably including audio output) allows the operator to immediately correlate movements of specific regions of wiring, or other circuit elements, with changes in the detected short conductance for the shorted circuit being tested. By way of example and not of limitation the tester may be implemented inexpensively with low cost analog circuitry, and does not require incorporating a microcontroller.

Claims17

Dependent claims

An apparatus for tracing electrical shorts in a wiring circuit under test, comprising:

means for producing a continuous source of substantially fixed current flow into a wiring circuit under test, said means for producing current configured for establishing an electrical connection to the wiring circuit anywhere along the length of the wiring circuit;
means for continuously monitoring voltage across said circuit under test, said means comprising,
a comparator circuit adapted to detect a plurality of sudden changes in applied voltage in response to said substantially fixed current flow,
a charge storage capacitor coupled to a first input of said comparator circuit configuring said comparator circuit to detect a first direction of voltage change in the wiring circuit in relation to a former voltage level;
and
means for audibly indicating a sudden change in circuit conductance, in relation to a preceding value of conductance and not a fixed value of conductance;
wherein said sudden changes in voltage are detected in response to voltage changes in the wiring circuit which exceed a predetermined voltage change within a given length of time and are communicated to said means for audibly indicating a sudden change.

4 more elements

Dependencies are inferred from the claim text.