Stjerne-til-trekant transformation

\[R_{12} = \frac{{R_{10} \cdot R_{20} + R_{20} \cdot R_{30} + R_{30} \cdot R_{10}}} {{R_{30}}}\]

\[R_{23} = \frac{{R_{10} \cdot R_{20} + R_{20} \cdot R_{30} + R_{30} \cdot R_{10}}} {{R_{10}}}\]

\[R_{31} = \frac{{R_{10} \cdot R_{20} + R_{20} \cdot R_{30} + R_{30} \cdot R_{10}}} {{R_{20}}}\]

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Trekant til stjerne transformation

\[R_{10} = \frac{{R_{12} \cdot R_{23}}}{{R_{12} + R_{23} + R_{31}}}\]

\[R_{20} = \frac{{R_{12} \cdot R_{31}}}{{R_{12} + R_{23} + R_{31}}}\]

\[R_{30} = \frac{{R_{23} \cdot R_{31}}}{{R_{12} + R_{23} + R_{31}}}\]

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