| 摘要 |
PURPOSE:To ensure the satisfactory stoppage at an end part of a stopping band, by connecting a capacitor which has sufficiently small impedance and the frequency characteristics approximately opposite to those of the effective resistance of an impedance element in parallel to an inductance element. CONSTITUTION:A resistance element 13 is connected in parallel to capacitors 11 and 12 of the same capacity connected in series. The joint of the capacitors 11 and 12 is earthed via a circuit in which a variable resistance element 17 is connected in series to an inductance element 16. Then a compensating capacitor 18 is connected in series to the element 16 of a filter which controls the level of resonance component with the element 17. The impedance of the capacitor 18 is set at a small value compared with those of capacitors 11 and 12 so that no substantial effect is given to the resonance frequency characteristics of a resonance circuit. At the same time, the impedance frequency characteristics are set approximately opposite to those of the element 16. |
