Patent ID: 6265879
Filing Date: 2001-07-24
Classification: G01N,G01R

Abstract:
An apparatus for applying a series of interrelated electrical tests to AC circuitry and an associated galvanic isolator having series semi-conductors, normally operative and arranged to block passage of DC currents in both directions and to permit passage of AC currents in both directions and to permit passage of AC currents through the galvanic isolator to earth ground, said apparatus comprising:a) means for applying a DC voltage of selected first polarity across a first silicon diode reference semi-conductor and of sufficient magnitude to establish what would be expected to be a normal voltage drop corresponding thereto;b) means for applying a DC voltage of said first polarity across said galvanic isolator and of sufficient magnitude to establish what would be expected to be a normal voltage drop corresponding thereto;c) means for comparing the voltage drop across said galvanic isolator with said voltage drop across said first silicon diode reference semi-conductor;d) means for applying a DC voltage of selected second polarity opposite said first polarity across a second silicon diode reference semi-conductor and of sufficient magnitude to establish what would be expected to be a normal voltage drop corresponding thereto;e) means for applying a DC voltage of said second polarity across said galvanic isolator and of sufficient magnitude to establish what would be expected to be a normal voltage drop corresponding thereto;f) means for comparing the voltage drop across said second silicon diode reference semi-conductor with said voltage drop across said galvanic isolator; andg) means for indicating whether the voltage drops corresponding to application of said DC voltages of said first and second polarities across said galvanic isolator and across said first and second silicon diode reference semi-conductors correspond to what would be normally expected.