摘要 |
<p>An inductance-based cable length-to-fault measurement device and method are described. The cable under test having a per-unit-length inductance is coupled to an inductance-sensitive oscillator, and the frequency of oscillations is evaluated using the following serially coupled modules: a comparator for digitizing the oscillator output, a pre-scaler for oscillation frequency down-conversion, and a microprocessor for counting pulses from the pre-scaler. To remove environmental and manufacturing tolerance dependencies, as well as a battery voltage dependence, the measured frequency of oscillations is compared to a frequency of oscillations of the oscillator having coupled thereto a reference inductor.</p> |