Murata Manufacturing Co., Ltd.

Mitsunao Okumura

Atsuo Senda

Shunjiro Imagawa

An ignition coil is provided with a primary coil which includes a distributed constant circuit including inductance and capacitance. A thyristor is connected in parallel to the primary coil, and a secondary coil is magnetically coupled to the primary coil. When a predetermined voltage is supplied to the primary coil, the capacitance is charged. If the thyristor is turned-on, the capacitance is discharged sequentially with time deviation since charge of the capacitance is sequentially delayed by the inductance which is connected in parallel to the capacitance.

Ignition coil

An electronic component includes a plurality of current path pairs which are arranged on the same circle. Currents flow through first current paths forming respective current path pairs in first directions, and currents flow through second current paths in second directions opposite to the first directions. The first current paths and the second current paths are arranged alternately. Therefore, magnetic fields generated by the currents in the first directions and magnetic fields generated by the currents in the second directions are canceled by each other, whereby residual inductance becomes small. In the case where the electronic component is a cable, the current paths are conductors buried in an insulation member. In the case where the electronic component is a capacitor, at least one of the current paths forming the pair is a capacitor unit.

Electronic component having a plurality of current path pairs

A 3-terminal capacitor includes a wound unit which includes first and second longitudinal insulation sheets having substantially the same length which are laminated. First and second conductors are respectively formed on corresponding main surfaces of the first and second insulation sheets, so that one of the insulation sheets is sandwiched between the two conductors. The first conductor is longitudinally formed with substantially the same length as the first insulation sheet, and the second conductor is formed to be sufficiently shorter than the second insulation sheet. When the first and second insulation sheets are wound together with the first and second conductors to form the wound unit, two first terminals fixed on the first conductor at a predetermined interval and a second terminal fixed on the second conductor are exposed outside the wound unit.

3-terminal capacitor

A pulse generator which employs a coaxial type capacitor, including at least one capacitor from which an accumulated charge is discharged when a pulse is generated, and another capacitor for adjusting the waveform of the pulse to be outputted. The coaxial type capacitor in this pulse generator includes at least first, second and third capacitors which are arranged coaxially and adjacent to each other. The first and third capacitors are connected in parallel to form the discharging capacitor of the pulse generator, while the second capacitor is arranged between the first and third capacitors and is used as the waveform adjusting capacitor of the pulse generator. A current in the second capacitor flows in a direction opposite to the direction of currents in the first and third capacitors when a pulse is generated.

Pulse generator including coaxial type capacitor

A noise filter including a wound unit which is composed of two film sheets one of which is laid on the other. On one film sheet, two first conductors are formed, and a second conductor is formed on the other film sheet. Four terminals are fixed to the first conductors in such a manner that one pair of the terminals are fixed to one of the first conductors and the other pair of terminals are fixed to the other first conductors. By laying one of the film sheets on the other film sheet and winding the same together with the first and second conductors, each of the first conductors opposes the second conductor, whereby distributed capacitance (C1) is formed between each of the first conductors and the second conductor. The capacitance is connected in series between the first conductors via the second conductor. Cores are inserted in a hollow portion of the wound unit, whereby inductances (L1, L2) are formed by the first conductors, respectively.

Noise filter

A noise filter includes a wound unit that is composed of two film sheets, one of which is laid on another. On the film sheets, conductors are respectively formed, to which terminals are fixed, respectively. By laying one of the film sheets on another film sheet and winding the same together with the conductors, the conductors on the respective film sheets oppose each other via the film sheet, whereby distributed capacitance is formed between the conductors. Cores are inserted in a hollow portion of the wound unit, whereby inductances are respectively formed by the respective conductors and the cores. The inductances connected between the terminals at an input side and the terminals at an output side, respectively. The above-described distributed capacitance is connected between the conductors that include the inductances.

A through type capacitor formed of a capacitor unit (or capacitor units) inserted through by a through terminal (or through terminals). The above through type capacitor mainly comprises a through terminal, a capacitor unit, a connecting member and a grounding member. The above grounding member is formed in the manner that the current flowing therethrough flows in the opposite direction to the current flowing through the capacitor unit. The above construction causes the counteracting of the residual inductance to reduce it as much as possible, which realizes a through type capacitor useful in a high frequency range.

Through type capacitor

A through type film capacitor comprising a capacitor unit, a through terminal extending axially of the capacitor unit, and an earthing terminal plate connected to one electrode of the capacitor unit. The capacitor unit includes a dielectric film in bellows form having inner and outer surfaces thereof coated with electrodes and fixed in an axially compressed form.

Through type film capacitor

A coaxial type capacitor for a pulse generator including at least a capacitor for discharging charge accumulated therein upon generating a pulse and a capacitor for adjusting a waveform of a pulse to be outputted. The coaxial type capacitor includes at least first, second and third capacitors which are arranged coaxially and adjacently with each other. The first and third capacitors between which the second capacitor is arranged are connected in parallel so as to form the discharging capacitor of the pulse generator while the second capacitor is used as the waveform adjusting capacitor of the pulse generator.

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Nagaokakyo, Japan

Mitsunao Okumura