| 摘要 |
PURPOSE:To enable to prevent the variation of stability of output voltage even when there is a current variation by a method wherein a toroidal form magnetic material with a gap and a gapless magnetic material are formed in one body, and a high permeability material is inserted in the gap. CONSTITUTION:A magnetic material 3a of toroidal shape has no gap, a magnetic material 3b of the same shape as material 3a has a gap, and a high permeability material 14 is inserted into the gap. The inductance of a choke coil constituted as above and having winding structure becomes the inductance which will be determined by the permeability of the materials 3a, 3b and 14 when the DC superposed current running to the choke coil is smaller than the value at which the material 14 is not magnetically saturated. When said DC superposed current is increased and the material 14 is magnetically saturated, the choke coil has the inductance which is determined by the permeability of the material 3b. Accordingly, the running current is hardly turned to discontinuous one even when the current running to the choke coil is reduced. |
