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Primary Examiner: Kominski, John
Assistant Examiner: Karlsen, Ernest F.
Attorney: Christoffersen; H.

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Title: Method of testing an electrical circuit

Abstract: A non-destructive method of testing an electrical circuit includes observing birefringent changes in a layer of liquid crystals during the operation of the circuit. The method comprises applying the layer of liquid crystals over the circuit with the liquid crystal molecules oriented in the same direction. A beam of light is directed through the layer of liquid crystals with an optical system adapted to make the birefringent changes visible. The circuit is energized with either an ac or a dc voltage, and the birefringent changes produced by the electric fields, and/or the currents, and/or the temperature distributions in the layer of liquid crystals are observed so that a comparison can be made between the observed birefringent changes and birefringent changes produced by a normally operating circuit.

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Inventors: Channin, Donald Jones (East Windsor, NJ, US)

Application Number: 455833
Filing Date: 1974-03-28
Publication_date: 1976-01-20
Assignee: RCA Corporation (NY)
Primary Class(es): 324/753 324/96, 324/752, 349/199
Other Classes:
US Patent Ref:
Other Refs: Other References: "Spotting IC Pin Holes with Liquid Crystals"; Electronics; Feb. 28, 1972; pp. 6E, 7E.