| 摘要 |
<p>PURPOSE:To provide a current sensor over a wide dynamic range. CONSTITUTION:A power amplifier 5 is arranged having a detection coil 3 and a feedback coil 4 on a magnetic core 2, and an induced electromotive force generated in the detection coil 3 by an alternating magnetic flux flowing through the magnetic core 2 is converted by current and applied to one end of the feedback coil 4. A second power amplifier 6 is so arranged as to invert an output voltage of the power amplifier 5 in polarity by an amplification factor and the output voltage inverted is applied to a reference resistor R connected in series to the other end of the feedback coil 4. Current runs to a current path comprising the feedback coil 4 and the reference resistor R from the first and second power amplifiers separately to cancel the alternating magnetic flux in the magnetic core 2 while a differential amplifier 7 is provided to detect a voltage generated in the reference resistor R by current.</p> |
