| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a current detection device which is less affected by a peripheral environment condition, is small-sized and low-cost, and is capable of detecting a minute current with low current consumption. <P>SOLUTION: The current detection device includes: an excitation coil 4 wound around a magnetic core 3 surrounding a conductor where a measurement current flows; oscillation means 6 which generates a rectangular wave voltage which inverts a direction of an excitation current supplied to the excitation coil, with the magnetic core in a saturated state or a state close to the saturated state in accordance with a set threshold; current detection means 7 which detects the measurement current on the basis of a duty change of the rectangular wave voltage outputted from the oscillation means 6; frequency detection means 8 which detects a frequency of the rectangular wave voltage outputted from the oscillation means; threshold setting means which sets a threshold of the oscillation means on the basis of the frequency detected by the frequency detection means; and number-of-turns selection means 5 which allows selection of the number of turns of secondary winding for supplying the excitation current, among a plurality of stages to change current detection characteristics. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
