| __Inductance Measuring Circuit__ *(Site not responding. Last check: 2007-11-02)* |

| | Other advantages to using a series **inductance** as a calibration **inductance** is that the circuit is guaranteed to oscillate for any value of test **inductance** (Ltest) and that the inaccuracies resulting from finite op-amp slew rate are cancelled out, even if the positive going slew rate differs from the negative going slew rate. |

| | The 220 ohm resistor is necessary to discharge the inductor during reversals in the polarity of the output voltage, otherwise a spike appears in the output voltage causing inaccuracies in the measured value of **inductance**. |

| | For a desired **inductance**, l, the designer should calculate the number of turns, N, then wind an inductor with a few more than N turns, and gradually back off the number of turns, by measuring the **inductance** with the test circuit below until the exact **inductance** is achieved. |

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