Patent ID: 7199692

Claim:
A noise suppressor suppressing noise transmitted through a first conductive wire and a second conductive wire, the noise suppressor comprising: a first inductor and a second inductor which are inserted into the first conductive wire in series with each other and are magnetically coupled to each other; a first capacitor which has one end connected between the first inductor and the second inductor; a third inductor which has one end connected to the other end of the first capacitor and the other end connected to ground, and forms a first series circuit together with the first capacitor; a fourth inductor and a fifth inductor which are inserted into the second conductive wire in series with each other, and are magnetically coupled to each other; and a second capacitor which has one end connected between the fourth inductor and the fifth inductor and the other end connected to the one end of the third inductor, and forms a second series circuit together with the third inductor, wherein a pair of the first and the second inductors and a pair of the fourth and the fifth inductors are magnetically coupled to each other, and an inductance L 3 of the third inductor satisfies the following condition: L 3=( M 1 +M 5)/2 (A-1), where M 1 =k 1( L 1 ·L 2) 1/2 , M 5 =k 5( L 1 ·L 5) 1/2 , L 1 : inductance of the first inductor, L 2 : inductance of the second inductor, L 5 : inductance of the fifth inductor, k 1 : coupling coefficient between the first and the second inductor, and k 5 : coupling coefficient between the first and the fifth inductor.