Abstract: An ignition device for an internal combustion engine that uses fuels including hydrogen. The ignition device includes an ignition coil including a primary coil and a secondary coil, a power supply device, a switching element, a spark plug, and a limiting diode. The switching element performs switching between passage and interruption of a primary current. The spark plug causes discharge at a gap, based on a high voltage induced at the secondary coil. The limiting diode includes a Zener diode that is forward-biased when oriented in a direction from the one end to the other end of the secondary coil. A breakdown voltage of the limiting diode is higher than the maximum value of an ON-state voltage obtained by multiplication of a value of a direct-current voltage applied to the primary coil by a ratio of the number of turns of the secondary coil to that of the primary coil.

Abstract: A boot of an ignition coil 2 includes: a main portion 18; a distal end portion 22; a seal portion 24 located between the main portion 18 and the distal end portion 22 and having a larger outer diameter than the main portion 18; and an air passage 28. When the ignition coil 2 is mounted on an internal combustion engine 20, the main portion 18 is exposed to an external environment, the distal end portion 22 is inserted in a plug hole 34 of the internal combustion engine 20, the seal portion 24 separates the external environment and the plug hole 34 from each other, and the air passage 28 connects the external environment and the plug hole 34 to each other. A first opening 44 of the air passage 28 is located in an outer circumferential surface of the main portion 18.

Abstract: A transformer includes: a coil: a core enclosing the coil, the core including a first surface, a second surface adjoining the first surface, and a third surface opposite to the first surface and adjoining the second surface; and a plurality of radiator plates each of which covers a part of the core. The first and third surfaces are covered by different radiator plates of the plurality of radiator plates. Preferably, the core further includes a fourth surface opposite to the second surface and adjoining the third surface, and the second and fourth surfaces are covered by different radiator plates of the plurality of radiator plates.

Abstract: A power conversion device suppresses voltage variation of a power supply bus. The device includes a variation compensation circuit and a control circuit. The variation compensation circuit includes: a first capacitor connected to the power supply bus; a second capacitor connected in series between the first capacitor and a ground; an auxiliary capacitor; and a converter including a switching element and having a voltage step-down function, the converter being connected to the second capacitor and the auxiliary capacitor. The control circuit includes an active power calculating section that calculates instantaneous active power ip in the variation compensation circuit. The control circuit controls the voltage Vc of the auxiliary capacitor using the instantaneous active power ip.

Abstract: A power conversion device suppresses voltage variation of a power supply bus. The device includes a variation compensation circuit and a control circuit. The variation compensation circuit includes: a first capacitor connected to the power supply bus; a second capacitor connected in series between the first capacitor and a ground; an auxiliary capacitor; and a converter including a switching element and having a voltage step-down function, the converter being connected to the second capacitor and the auxiliary capacitor. The control circuit includes a proportional resonant control section having a peak gain for variation with a frequency ?0 which is twice a frequency of the single-phase alternating current. The control circuit uses the proportional resonant control section to generate a signal for controlling the switching element.

Abstract: An ignition device includes a coil unit and an igniter. The coil unit includes a primary coil and a secondary coil. The primary coil includes a main primary coil and an auxiliary primary coil formed by winding a single primary conductor on a primary bobbin. The secondary coil is formed by winding a secondary conductor on a secondary bobbin. A DC voltage is applied to an intermediate section of the primary conductor between the main primary coil and the auxiliary primary coil. The igniter controls current flowing into the main primary coil or the auxiliary primary coil. The primary bobbin includes a bobbin body and a hooking part protruding from the bobbin body. The main primary coil and the auxiliary primary coil are wound on an outer peripheral surface of the bobbin body to the same direction. A part of the intermediate section is hooked on the hooking part.

Abstract: Electronic equipment includes a plurality of heat generating elements, a single heat sink, and a single cover. The heat generating elements are arranged adjacent to one another in a one-dimensional array in a predetermined alignment direction. The faces of the heat generating elements on one side are fixed directly or indirectly to the heat sink. The faces of the heat generating elements on the other side are in direct or indirect contact with the cover. The cover is fixedly screwed to the heat sink at opposite ends in the alignment direction on the outer side of the heat generating elements. The heat generating elements are sandwiched and held between the heat sink and the cover. This allows heat generated by the heat generating elements to be efficiently radiated via the heat sink and allows the heat generating elements to be easily connected to the heat sink.

Abstract: An ignition coil includes a not-illustrated coil, a plate assembly, and a case assembly. The plate assembly and the case assembly are combined with each other by laser welding at a recess and a rib (projection) which are respective abutting portions, thereby forming storage spaces for storing the coil.

Abstract: A DC-DC converter has a configuration in which a first full-bridge circuit and a second full-bridge circuit are connected via a transformer and an inductor. A control circuit performs soft switching of each switching element in the first full-bridge circuit and the second full-bridge circuit. An inductor current flowing through an equivalent inductor at a time of switching of turning on or off each switching element is greater than or equal to a threshold current, the equivalent inductor being equivalent to the transformer and the inductor.

Abstract: In a transformer, forward and reverse secondary coils are connected to a single reference electrode or any of a plurality of reference electrodes. The forward secondary coil includes first and second winding portions wound around a forward iron core. The reverse secondary coil includes third and fourth winding portions wound around a reverse iron core. A first primary coil is formed around the first and third winding portions. The second primary coil is formed around the second and fourth winding portions. The single reference electrode or each of the plurality of reference electrodes is in the form of a plate.

Abstract: The DC-DC converter has a configuration in which a first full-bridge circuit and a second full-bridge circuit are connected via a transformer. A control circuit controls soft switching of each switching element. An inductor current flowing through the transformer or an equivalent inductor equivalent to the transformer at a time of switching of turning on or off each switching element is greater than or equal to a threshold current. When the first full-bridge circuit and the second full-bridge circuit have different output voltages V1 and V2, the control circuit causes the inductor current at start times t4 and t8 of a polarity inversion period to approach the inductor current at end times t5 and t9, the polarity inversion period being a period in which V1 and V2 have reverse polarities. This suppresses an increase in loss resulting from a flow of large current and enables ZVS control.