| 摘要 |
PURPOSE:To eliminate even a radiation noise having a frequency component as high as several 100MHz by employing a 3-terminal capacitor for a by-pass capacitor for common mode noise connected between a line and ground. CONSTITUTION:After the common mode noise reaching an output terminal 13 from a choke coil 18 is attenuated by an inductance L1 of a ferrite bead 40a of the 3-terminal capacitor C12, the noise reaches an electrode 36 of a capacitor unit 33, is by-passed to ground by a capacitor unit 38 and subjected to attenuation by an inductance L2 of a ferrite bead 40b. Similarly, the common mode noise reaching an output terminal 14 from a choke coil 19 is subjected to attenuation by a 3-terminal capacitor C13. Moreover, legs 39a, 39b of a lead terminal 39 in the 3-terminal capacitors C12, C13 act as elements attenuating the noise. Thus, the upper limit of a noise frequency eliminated by the line filter is improved up to nearly 300MHz and the radiation noise is eliminated effectively. |
