A cable distribution plant is protected from noise by a distributed cable modem filter.

A noise filter (A) includes a case (10) and capacitors (20) accommodated in the case (10). Substantially flat surfaces of the capacitors (20) serve as ground-side electrodes (23). A ground terminal (17) is connected directly to the ground-side electrodes (23), and input/output terminals (15) are connected to input/output-side electrodes (21) of the capacitors (20). A routing space for leads for connecting the capacitors (20) and the ground terminal (17) is not necessary in the case (10). Therefore, the case (10) can be miniaturized.

Disclosed herein is a common mode filter that includes a winding core part and first and second wires wound in a same direction around the winding core part. The first and second wires constitute a first winding block on one endmost side in an axial direction of the winding core part, a second winding block on other endmost side in the axial direction of the winding core part, and a third winding block positioned between the first and second winding blocks. The second winding block is a winding block at an odd-numbered position counted from the first winding block. The first and second wires cross each other in an area between the first and third winding blocks and in an area between the second and third winding blocks.

Provided is a filter device to be connected between an AC power source (1) and a PWM converter (2), which includes a first AC reactor (3), a second AC reactor (4) that is connected between the PWM converter (2) and the first AC reactor (3), a filter capacitor (5) whose one end is connected to a connecting portion (9) between the first AC reactor (3) and the second AC reactor (4), and a housing (15) having a cooling air inlet (16) and a cooling air outlet (17) and containing the first AC reactor (3) and the second AC reactor (4), wherein the first AC reactor (3) is disposed upwind of the second AC reactor (4).

A board-type noise filter having higher noise removal performance than that of a conventional noise filter, and an electronic device including the board-type noise filter are provided. The board-type noise filter includes: a printed wiring board having a wiring pattern formed thereon; a choke coil including a core having a toroidal shape; a frame ground portion fixed to the printed wiring board at a position overlapping with a hollow portion of the choke coil when the toroidal shape of the choke coil is seen in plan view, the frame ground portion being capable of being grounded to a frame ground; and a capacitor having a first terminal connected to the frame ground portion through the wiring pattern.

A common mode noise filter includes a laminated body having insulator layers therein and first and second spiral conductors provided on layer planes different from each other. The first spiral conductor includes a first spiral conductor line, a first pad provided at an outer end of the first spiral conductor line, and a second pad provided at an inner end of the first spiral conductor line. The second spiral conductor includes a second spiral conductor line, a third pad provided at an outer end of the second spiral conductor line, and a fourth pad provided at an inner end of the second spiral conductor line. The first spiral conductor line faces the second spiral conductor line. Each of the second pad and the sixth pad overlaps none of the fourth pad and the eighth pad viewing from above.

Disclosed herein is a differential mode filter that includes first and second terminal electrodes provided on a first flange part of a core, and first and second wires wound around a winding core part of the core in an opposite direction to each other and connected respectively to the first and second terminal electrodes. The first and second wires cross each other on the winding core part to form a plurality of crossing portions that include first, second, and third crossing portions that are first, second, and third occurrences counting from the one end of the first and second wires, respectively. A first crossing angle between the first and second wires at the first crossing portion is larger than at least one of second and third crossing angles between the first and second wires at the second and third portions, respectively.

Disclosed herein is a common mode filter that includes first and second terminal electrodes provided on the first flange part, third and fourth terminal electrodes provided on the second flange part, a first wire wound around the winding core part and having one end connected to the first terminal electrode and other end connected to the third terminal electrode, and a second wire wound around the winding core part and having one end connected to the second terminal electrode and other end connected to the fourth terminal electrode. The winding core part includes a first winding region, a second winding region, and a third winding region positioned between the first and second winding regions in the axial direction. The first and second wires are bifilar-wound in the first and second winding regions and layer-wound in the third winding region.

Disclosed herein is a common mode filter that includes: a winding core part including first and second winding areas and a third winding area positioned between the first and second winding areas; and first and second wires wound in a same direction around the winding core part. The first and second wires constitute a first winding block wound in the first winding area and a second winding block wound in the second winding area. The first and second wires cross each other in the third winding area. Each of the first and second winding blocks has first and second winding layers. The difference in a number of turns between the first winding layer and the second winding layer is larger in the first winding block than in the second winding block.

Disclosed herein is a common mode filter that includes a winding core part and first and second wires wound in a same direction around the winding core part. The first and second wires constitute a first winding block on one endmost side in an axial direction of the winding core part, a second winding block on other endmost side in the axial direction of the winding core part, and a third winding block positioned between the first and second winding blocks. The second winding block is a winding block at an odd-numbered position counted from the first winding block. The first and second wires cross each other in an area between the first and third winding blocks and in an area between the second and third winding blocks.