| 摘要 |
<p>PURPOSE:To accurately measure dc current over a wide range by using two sources having different wavelength and dividing these two light waves into two polarized components which are perpendicular to each other at a light emitting end of a magnetic field sensor. CONSTITUTION:Two light waves having different wavelength are generated by light sources 1, 2 and made incident to an optical fiber 4 by a light synthesizer 3. A polarizer 5 polarizes the light wave of first wavelength of the two light waves to make it linearly polarized light and allows light of second wavelength to be passed through without polarization. An analyzer 7 divides both light waves of two wavelength into perpendicularly polarized components, P polarized light and S polarized light components. Of the polarized light components, the P polarized component is transmitted by an optical fiber 11 to a signal processing circuit 50 and the S polarized component is transmitted by an optical fiber 12 to the signal processing circuit 50. In the circuit 50, light branching filters 13, 14 divide the light waves into a light signal of first wavelength and a light signal of second wavelength due to difference in wavelength of the two light waves, which are converted into electric signals by photo diodes 21 to 24 and enter an arithmetic processing circuit 30. The circuit 50 can be used to measure dc current.</p> |
