An apparatus, and a method using the apparatus, for filtering common mode and differential mode currents, wherein the apparatus comprises a first magnetic core element made of a first magnetic material, a second magnetic core element made of a second magnetic material, wherein permeability characteristics of the second magnetic material differ from permeability characteristics of the first magnetic material, and at least one winding, wherein each winding is arranged to magnetize the first and the second magnetic core.

A method for providing an isolated logic output signal, comprising: in response to receiving an input data signal, generating an edge detection signal indicating a rising or falling edge of the received input data signal; transforming the edge detection signal from a first voltage to a second voltage; inputting the transformed edge detection signal to a first input of a first logic circuit and to an input of a signal generator; outputting from the signal generator a logic signal to a second and third input of the first logic circuit, wherein the logic signal is representative of a duration of the edge detection signal; and in response to an output from the first logic signal, generating an isolated logic output signal.

The invention provides a common-mode choke coil having a structure capable of preventing malfunction of transmission IC and receiving IC in an immunity test, thereby improving immunity property.

A common-mode choke coil is provided with a core 2, external electrodes 3-1 to 3-4, a pair of wires 4-1 and 4-2, and a top plate 5. The core 2 includes a winding core portion 20 and a pair of flanges 21 and 22 at both ends of the winding core portion 20. The upper surface 20a of the winding core portion 20 and the upper surfaces 21c and 22c of the flanges 21 and 22 are covered with a metal film 6. The external electrodes 3-1 to 3-4 are formed on lower portions of the flanges 21 and 22. A pair of wires 4-1 and 4-2 are wound on the winding core portion 20 of the core 2, and the ends 4-1a and 4-2a of the wires 4-1 and 4-2 are joined to the external electrodes 3-1 and 3-2, respectively, and the ends 4-1b and 4-2b of the wires 4-1 and 4-2 are joined to the external electrodes 3-3 and 3-4, respectively. The top plate 5 is bonded to the upper surfaces 21c and 22c of the flanges 21 and 22 with an adhesive 7.

A dielectric ceramic composition comprises as a main component, Cu oxide, Si oxide and one selected from the group consisting of Zn oxide alone and a combination of Mg oxide and Zn oxide, as a subcomponent, a glass component including B oxide and at least one selected from the group consisting of Si oxide, Ba oxide, Ca oxide, Sr oxide, Li oxide and Zn oxide, and having a glass softening point is 750°C or less, wherein a content of said glass component is 1.5 to 15wt% with respect to 100wt% of said main component.

According to the present invention, a dielectric ceramic composition can be provided which is available to be sintered at low temperature (for example, 950°C or lower) while comparatively decreasing contents of a glass component, which shows good properties (specific permittivity, loss Q value and insulation resistance), and which is available to perform cofiring different materials.

DC bias characteristics of an open magnetic circuit type layered coil component are improved.

A layered coil component (1) includes a coil that is constructed by layering coil conductor patterns (5) and ceramic sheets. The ceramic sheets include a first ceramic sheet and a third ceramic sheet (4) having a permeability lower than the permeability of the first ceramic sheet. The third ceramic sheet (4) has an arrangement that is astride at least two of the coil conductor patterns (5) adjacent to each other in a layering direction, in a section including a coil axis of the coil (L).

A coil unit including an annular toroidal core (11,21,31,41,51,61) two coils (12,22,32,42,52,62) wound over the toroidal core providing a bifilar winding, a winding-start positioning part (11C,21D,31C,41D,51B,61B), and a winding-end positioning part (11D,21E,31D,41E,51C,61C). The winding-start positioning part is adapted for making contact with a winding-start portion of the coils. The winding-end positioning part is adapted for making contact with a winding-end portion of the coils for regulating the positions of the winding-start portion and the winding-end portion relative to the toroidal core.

L'invention concerne un dispositif de filtrage qui comprend une inductance de mode commun (L_F) comportant un enroulement (L1,L2) sur chaque ligne d'un réseau d'alimentation alternatif et un noyau magnétique composé d'un premier tore (T1) et d'un second tore (T2). Le premier tore (T1) est doté d'une première perméabilité magnétique (µ1) et le second tore (T2) est doté d'une seconde perméabilité magnétique (µ2,µ'2), la première perméabilité étant supérieure ou égale au triple de la seconde perméabilité, pour éviter la saturation de l'inductance de mode commun dans la zone de fréquence de résonance du dispositif de filtrage. Application au filtre CEM d'un variateur de vitesse.

The invention aims at putting a single ended resonance type converter capable of obtaining a ZVS operation over an overall corresponding load region to practical use. A switching power source circuit is structured in which a primary side switching converter is structured as being of a class-E resonance type, and a choke coil of a primary side series resonance circuit of the class-E resonance type converter is used as a primary winding of an insulating converter transformer. With this structure, a choke coil winding to be inserted into an input line of a DC input voltage is inserted between a positive-polarity end portion of a smoothing capacitor, and a node between the primary winding and a primary side series resonance capacitor. Thus, a resonance pulse voltage generated in a choke coil winding is superimposed on an AC voltage in the primary winding. Also, a primary series resonance current is caused to separately flow through the choke coil winding. The switching power source circuit operates in such a manner.

A plurality of conductor pattern layers (2, 3, and 4) for a coil overlaps each other to form U-shaped conductors (2A, 3A, and 4A) for the coil. The conductors (2A, 3A, and 4A) for the coil are electrically connected in series with via holes (15) for interlayer connection provided in ceramic green sheets (10 and 11) to form a spiral coil (L). A plurality of leading conductor pattern layers (5 and 6) also overlaps each other to form leading conductors (5A and 6A). One leading conductor pattern layer (5) is disposed per predetermined number of conductor pattern layers (2) for the coil. An end (51) of each leading conductor pattern layer (5) is in contact with the corresponding conductor pattern layer (2) for the coil. In other words, the thickness of the leading conductors (5A and 6A) is smaller than the thickness of the conductors (2A to 4A) for the coil.

A winding 36 of a choke coil 31 is closely wound in a single layer on the outer periphery of a cylindrical body portion 33 of a bobbin 32. A winding 37 is closely wound in a single layer over the winding 36. A winding 46 is closely wound in a single layer on the outer periphery of a cylindrical body portion 43 of a bobbin 42. A winding 47 is closely wound in a single layer over the winding 46. The windings 36, 37, 46, and 47 are wound so as to mutually strengthen magnetic fluxes when an in-phase noise current flows. The windings 36 and 37 are connected to a pair of signal lines via which differential transmission communication is performed and on which a power supply current goes. The windings 46 and 47 are connected to a pair of signal lines via which differential transmission communication is performed and on which the power supply current returns. Thus, a circuit using a compact choke coil having large inductance and better high-frequency characteristics, and the choke coil can be provided.

For providing an isolation between an input signal and an output signal, a transformer arrangement includes a planar medium (300) having first and second layers, and a dielectric interlayer arranged therebetween; at least one meandering primary winding (105a) arranged on the first layer; at least one meandering secondary winding (110) arranged on the second layer, the primary and secondary windings forming a planar transformer, such that a current flow induced within the primary winding by the input signal induces a voltage across the secondary winding; and a mode elimination arrangement for producing a compensated voltage by compensating for a common mode interference on the voltage induced across the secondary winding, the mode elimination arrangement generating the output signal in accordance with the compensated voltage; wherein the dielectric interlayer of the planar medium provides a voltage isolation between the primary and secondary windings.

A common mode choke coil has first and second spiral conductive layer elements electrically insulated from each other at a base. The base is made of a magnetic material or a dielectric material. at least one of the first and the second spiral conductive layer elements is formed in close contact with a surface of the base. The common mode choke coil has two spiral conductor layer elements at a base. Therefore, the common mode choke coil may be easily and economically provided that has high Q-characteristics or high impedance at a common mode and little fluctuation of resonance frequencies and inductance.

A common mode choke coil has first and second spiral conductive layer elements electrically insulated from each other at a base. The base is made of a magnetic material or a dielectric material. at least one of the first and the second spiral conductive layer elements is formed in close contact with a surface of the base. The common mode choke coil has two spiral conductor layer elements at a base. Therefore, the common mode choke coil may be easily and economically provided that has high Q-characteristics or high impedance at a common mode and little fluctuation of resonance frequencies and inductance.

A laminated LC element comprises a laminate including a plurality of bonded insulating layers (32-1, 32-2 ...), a first conductor (40) including conductive elements (44-1, 44-2 ...) which continuously extend around the insulating layers so as to form a coil having a predetermined number of turns; and a second conductor (50) including second conductive elements (54-1, 54-2 ...) which extend around the insulating layers, facing the first conductor via said insulating layers, and producing a capacitance with the first conductor. The LC element can eliminate firmly noises from external sources.