In an embodiment a coil includes a tube comprising a tube wall composed of an electrically conductive material, wherein the tube wall has an inductive portion in which a gap is arranged that shapes the tube wall so the tube wall forms a helix in the inductive portion, and wherein the tube wall has two contact portions, each contact portion forming an electrical terminal.

An ignition coil includes a primary coil, a secondary coil, a primary bobbin, a secondary bobbin, a center core, and a mold resin. The center core has a pair of collar portions protruding from a main body of the center core respectively to opposite sides in a protruding direction. The primary bobbin has a collar portion at least partially sandwiched between the collar portions of the center core and the secondary bobbin in a coil axial direction. The collar portion of the primary bobbin includes an overlapping portion that overlaps the collar portions of the center core in the coil axial direction and is bonded to the collar portions. The primary bobbin is formed of a thermoplastic resin and dispersed-phase particles dispersed in the thermoplastic resin. In the overlapping portion of the primary bobbin, there is formed a specific separating layer that separates adjacent layers in the coil axial direction.

A method of insulating a coil of a toroidal transformer, comprising forming an opening in an electrically insulating thermoplastic cup receiving an iron core with a coil for leading through terminals of the coil, arranging the iron core with the coil in the cup with the coil terminals are led out of through the opening, covering the cup with a plastic lid which engages the cup in a form-fitting manner, temporarily fixing the cup comprising the iron core and coil in an irrotatable manner, joining the cup and the lid by rotary friction by rotating welding by pressing the lid against the cup in a pressed state until the lid and the cup heat up and their material soften and become viscous due to friction, stopping the rotation of the lid within not more than one second after softening while maintaining the pressure of the lid and the cup to join their mixed material to form a continuous electrical insulation.

The manufacturing method of a motor core includes attaching an ID code to a stack of blanked members in which a magnet insertion hole to fill with a resin material is formed, the ID code containing information in accordance with a type of the stack, reading the information from the ID code which is attached to the stack, and setting a mold condition based on the information read from the ID code. The mold condition includes at least one type of condition including: the resin material to be injected to the magnet insertion hole, an injection amount of the resin material, and a discharge position of the resin material. A mold device is controlled to inject the resin material to the magnet insertion hole in accordance with the mold condition.

An iron-based oxide magnetic powder has good thermal stability and a small change in coercive force even in a high-temperature environment and is one composed of particles of ε-iron oxide in which Fe sites are partially substituted by another metal element. A production method for such an iron-based oxide magnetic powder includes allowing a phosphorus-containing ion to coexist when a precipitate of an iron hydroxide containing a substituent metal element produced by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites is coated with silicon oxide using a silane compound.

An iron-based oxide magnetic powder has good thermal stability and a small change in coercive force even in a high-temperature environment and is one composed of particles of ε-iron oxide in which Fe sites are partially substituted by another metal element. A production method for such an iron-based oxide magnetic powder includes allowing a phosphorus-containing ion to coexist when a precipitate of an iron hydroxide containing a substituent metal element produced by neutralizing an acidic aqueous solution containing a trivalent iron ion and an ion of a metal that partially substitutes Fe sites is coated with silicon oxide using a silane compound.

A test device according to an embodiment of the present invention includes: a first measurement terminal connected to one end of a first coil to be tested; a second measurement terminal connected to another end of the first coil; a direct-current power source connected to the first measurement terminal; a first semiconductor switch connected between the second measurement terminal and a ground; and a drive unit for turning on and off the first semiconductor switch.

A test device according to an embodiment of the present invention includes: a first measurement terminal connected to one end of a first coil to be tested; a second measurement terminal connected to another end of the first coil; a direct-current power source connected to the first measurement terminal; a first semiconductor switch connected between the second measurement terminal and a ground; and a drive unit for turning on and off the first semiconductor switch.

A stacked electronic module includes a magnetic device comprising a magnetic body with electrodes of the magnetic device being disposed on a top and bottom surface of the magnetic body, wherein a molding body encapsulates the magnetic body, wherein conductive layers are disposed on a top and bottom surface of the molding body for electrically connected to the electrodes of the magnetic device.

A module includes a substrate including a first main surface, a first component mounted on the first main surface, a first sealing resin including a first upper surface, the first component being sealed with the first sealing resin, a first shield film that covers at least a part of the first upper surface of the first sealing resin, and a second shield film that covers a side surface of the first sealing resin and a side surface of the substrate. A step portion lower than the first upper surface of the first sealing resin is provided on an outer periphery of the first sealing resin. The first shield film and the second shield film are electrically connected to each other on a side surface below the step portion.