| 摘要 |
PURPOSE:To attain an attenuation characteristic effective even for a high-level noise of high frequency components in the normal use state by using a ferrite core, whose complex permeability is maximum for >=1MHz frequency, as a magnetic core for choke coil. CONSTITUTION:An Ni-Zn ferrite core is given as magnetic materials whose complex permeability mu'' is maximum for >=1MHz frequency, and frequency characteristics of a phase angle theta and an impedance ¦Z¦ of the choke coil using this Ni-Zn ferrite core are shown in figures (a) and (b). A common mode choke coil 7 having an Mn-Zn ferrite core 12 as the magnetic core has a large impedance in a low frequency has a function to eliminate the noise of low frequency components, and a common mode choke coil 8 having an Ni-Zn ferrite core 13 as the magnetic core has a large impedance in a high frequency and eliminates the noise of high frequency components, and thus, the common mode noise is eliminated in a wide band. |
