| 摘要 |
<P>PROBLEM TO BE SOLVED: To make magnetic saturation in a choke coil hard to occur. <P>SOLUTION: A noise filter device for reducing a common mode noise or a normal mode noise in an electric circuit includes: a choke coil having a main coil wound around a magnetic core, thereby forming an electric conduction path between a power supply and a load; a cooler for cooling the choke coil, having a variable cooling capacity; an auxiliary winding for current detection which is wound around the magnetic core of the choke coil; and when a current magnitude flowing in the auxiliary winding is greater than a threshold, a control circuit to increase the cooling capacity by the cooler, as compared to a case when the current magnitude is smaller than the threshold. <P>COPYRIGHT: (C)2012,JPO&INPIT |
