Abstract: A signal transmission circuit has first to fourth inductors, and first and second varistors. The first and second inductors are magnetically coupled to each other. The first varistor is connected to ground and located posterior to the first inductor and is electrically connected to the first inductor. The third inductor is located between the first inductor and the first varistor and is electrically connected to the first inductor. The second varistor is connected to ground and located posterior to the second inductor and is electrically connected to the second inductor. The fourth inductor is located between the second inductor and the second varistor and is electrically connected to the second inductor.

Abstract: A common mode choke coil has a first coil element and a second coil element. The first coil element is configured of a first coil pattern and a second coil pattern. Each of the first and second coil patterns has two ends and is spiral-shaped therebetween. The spirals of the two patterns are wound in the same direction. The second coil element has a shape identical to the first coil element and includes a third coil pattern corresponding to the first coil pattern and a fourth coil pattern corresponding to the second coil pattern.

Abstract: A signal transmission circuit having a characteristic impedance includes a common mode filter, a first capacitive element, a first connection line, a second capacitive element and a second connection line. The first capacitive element has a first terminal. The first connection line connects one output of the common mode filter to the first capacitive element. The second connection line connects the other output of the common mode filter to the second capacitive element. The first connection line has a first length. The second connection line has a second length. Each of the first length and the second length is within a predetermined range to change the characteristic impedance.

Abstract: A coil assembly for reducing variations in characteristic impedance includes a winding section having a first surface and a second surface on the opposite side of the winding section from the first surface, a plurality of first protrusions provided on the first surface, and a plurality of second protrusions provided on the second surface. These protrusions are identical in shape to each other and are arrayed linearly on their respective surfaces so that the first protrusions are offset from the second protrusions. Two conducting wires are wound between neighboring protrusions such that one wire contacts one of the neighboring protrusions, while the other wire contacts the other neighboring protrusion.

Abstract: A common-mode choke coil has first and second coil parts, a first inductance part, and a second inductance part. The first coil part and the second coil part are magnetically coupled to each other. The first inductance part is electrically connected in series to the first coil part and is not substantially magnetically coupled to the first coil part. The second inductance part is electrically connected in series to the second coil part and is not substantially magnetically coupled to the second coil part. The first inductance part and the second inductance part are not substantially magnetically coupled to each other.

Abstract: A noise filter available for various cable widths and capable of being easily attached to a cable. The noise filter has a first core having both ends to which first and second holding members and are attached, and a second core having both ends to which third and fourth holding members and are attached. First and second contacting portions and are formed on a first facing surface at the first core. Third and fourth contacting portions are formed on a second facing surface at the second core. When the first and second contacting portions are brought into contact with the third and fourth contacting portions an insertion hole is provided between the first and second contacting portions and between the first and second facing surfaces. The first and third holding members are coupled to each other by a retaining portion and retaining projection. The second and fourth holding members and are coupled to each other by a hinge portion.

Abstract: A noise filter providing a simplified construction and capable of being used regardless of a diameter of a cable or a numbers of cables. The noise filter includes a core-holding section for holding a core, first and second cable-guiding sections, and two coupling sections coupling the first and second cable-guiding sections to ends of the core-holding section. The first and second cable-guiding section have truncated conical shape, and each divided into the four parts by a first to fourth slits arrayed in cruciform shape whose crossing position is coincident with an imaginary apex of the cable-guiding section. The coupling section has first to fourth circumferential elongated slots in communication with the proximal ends of the first to fourth slits.

Abstract: A common mode choke coil has a first coil element and a second coil element. The first coil element is configured of a first coil pattern and a second coil pattern. Each of the first and second coil patterns has two ends and is spiral-shaped therebetween. The spirals of the two patterns are wound in the same direction. The second coil element has a shape identical to the first coil element and includes a third coil pattern corresponding to the first coil pattern and a fourth coil pattern corresponding to the second coil pattern.

Abstract: A noise filter providing a simplified construction and capable of being used regardless of a diameter of a cable or a numbers of cables. The noise filter includes a core-holding section for holding a core, first and second cable-guiding sections, and two coupling sections coupling the first and second cable-guiding sections to ends of the core-holding section. The first and second cable-guiding section have truncated conical shape, and each divided into the four parts by a first to fourth slits arrayed in cruciform shape whose crossing position is coincident with an imaginary apex of the cable-guiding section. The coupling section has first to fourth circumferential elongated slots in communication with the proximal ends of the first to fourth slits.

Abstract: A coil assembly for reducing variations in characteristic impedance includes a winding section having a first surface and a second surface on the opposite side of the winding section from the first surface, a plurality of first protrusions provided on the first surface, and a plurality of second protrusions provided on the second surface. These protrusions are identical in shape to each other and are arrayed linearly on their respective surfaces so that the first protrusions are offset from the second protrusions. Two conducting wires are wound between neighboring protrusions such that one wire contacts one of the neighboring protrusions, while the other wire contacts the other neighboring protrusion.

Abstract: A common-mode filter with a drum type core including a core portion and flange portions. Electrodes are provided on the flange portions and a pair of wires are wound on the core portion. The wound pair of wires have ends connected to respective ones of the electrodes. Each of the flange portions has a groove between corresponding two of the electrodes and a separation protrusion for separating the groove into two lead-out groove portions. The pair of wires are wound on the core portion in such a distributed winding manner that an inter-wire distance between the pair of wires and a winding pitch between adjacent turns in each of the pair of wires are provided. The wires are one-by-one led out through the lead-out groove portions while separated by the separation protrusions so that the ends of the pair of wires are connected to respective electrodes.

Abstract: A common-mode choke coil has first and second coil parts, a first inductance part, and a second inductance part. The first coil part and the second coil part are magnetically coupled to each other. The first inductance part is electrically connected in series to the first coil part and is not substantially magnetically coupled to the first coil part. The second inductance part is electrically connected in series to the second coil part and is not substantially magnetically coupled to the second coil part. The first inductance part and the second inductance part are not substantially magnetically coupled to each other.

Abstract: A signal transmission circuit has first to fourth inductors, and first and second varistors. The first and second inductors are magnetically coupled to each other. The first varistor is located posterior to the first inductor and is electrically connected in parallel to the first inductor. The third inductor is located between the first inductor and the first varistor and is electrically connected in series to the first inductor. The second varistor is located posterior to the second inductor and is electrically connected in parallel to the second inductor. The fourth inductor is located between the second inductor and the second varistor and is electrically connected in series to the second inductor.

Abstract: A signal transmission circuit having a characteristic impedance includes a common mode filter, a first capacitive element, a first connection line, a second capacitive element and a second connection line. The first capacitive element has a first terminal. The first connection line connects one output of the common mode filter to the first capacitive element. The second connection line connects the other output of the common mode filter to the second capacitive element. The first connection line has a first length. The second connection line has a second length. Each of the first length and the second length is within a predetermined range to change the characteristic impedance.

Abstract: A common-mode filter comprising: a drum type core 10 including a core portion 11, and quadrangular flange portions 12; electrodes 20 provided on the flange portions 12 of the drum type core 10; and a pair of wires land 2 wound on the core portion 11 of the drum type core 10 and having ends connected to the electrodes 20 respectively, wherein: each of the flange portions 12 has a groove 15 between corresponding two of the electrodes 20, and a separation protrusion 16 for separating the groove 15 into two lead-out groove portions 17a and 17b; the wires 1 and 2 are wound on the core portion 11 of the drum type core 10 in such a distributed winding manner that an inter-wire distance (a) between the wires 1 and 2 and a winding pitch (b) between adjacent turns in each of the wires 1 and 2 are provided; and the wires 1 and 2 are one-by-one led out through the lead-out groove portions 17a and 17b while separated by the separation protrusions 16 so that the ends of the wires 1 and 2 are connected to the electrodes 20

Abstract: A coil component is provided which includes a pot core having a bottom in which through holes are formed, a composite coil retained in the pot core, and a cover core joined to the rim of the pot core. The coil has terminals inserted in the through holes to such an extent that the lower ends thereof do not protrude beyond the bottom, the bottom having membrane external electrodes formed on the outer surface thereof and connected with the terminals. The composite coil comprises an inner coil wound around an inner leg of the pot core and an outer coil wound around the inner coil with a gap formed between the inner and outer coils so as to make larger the length of the outer coil than the case where the outer coil is directly wound around the inner coil.

Abstract: A coil component is provided which includes a pot core having a bottom in which through holes are formed, a composite coil retained in the pot core, and a cover core joined to the rim of the pot core. The coil has terminals inserted in the through holes to such an extent that the lower ends thereof do not protrude beyond the bottom, the bottom having membrane external electrodes formed on the outer surface thereof and connected with the terminals. The composite coil comprises an inner coil wound around an inner leg of the pot core and an outer coil wound around the inner coil with a gap formed between the inner and outer coils so as to make larger the length of the outer coil than the case where the outer coil is directly wound around the inner coil.