| 摘要 |
<p>PURPOSE:To make it possible to follow up even a sudden change in a detected current without generating noise, by adding up an output from a magnetoelectric conversion element and a detected value of a current outputted from a coil. CONSTITUTION:A magnetoelectric conversion element 2 and an input end of an amplifier 4 are connected, an output end of the amplifier 4, one end of a coil 3 wound by the number of winds N2 on a magnetic body 1, and one end of a resistor 5 of resistance R, are connected together, and further the other end of the coil 3 and the other end of the resistor 5 are connected. An output from the element 2 is amplified by the amplifier 4, and an output V1 thereof and an output V2 obtained by converting an output current i2 from the coil 3 into a voltage by the resistor 5 are added up. Thereby an output voltage Vout is obtained and a current i1 is detected. The output Vout is in a proportional relation with the detected current i1 and a magnetic flux phi turns to be in a relation of primary delay with the detected current i1. Since dphi/dt becomes small, in other words, generation of noise is prevented substantially and a hyster esis loss and an eddy current loss in the magnetic body 1 which increase in accordance with the frequency of the magnetic flux can be reduced to be small.</p> |
