Patent ID: 7148767
Filing Date: 2006-12-12
Classification: H01F,H03H

Abstract:
1. A bead type noise filter which comprises a magnetic core having a through-hole so as to form a closed magnetic path, and which is attached on one of a signal wire and a power wire such that the wire passes through the closed magnetic path of the magnetic core, wherein the magnetic core is formed of a soft magnetic material which has a real part of complex relative permittivity ranging from 1,000 up to 20,000 at 1 kHz, and 50 or lower at 1 MHz, and which has a resistivity of 150 Ωm or higher, and wherein the magnetic core has an impedance composed of a reactance component and a resistance component, and a crossing frequency between a frequency characteristic of the reactance component and a frequency characteristic of the resistance component is less than 5 MHz.