A punching method includes: punching out a plurality of electrical steel sheets in a stacked state by a mold, wherein sheet thicknesses of the electrical steel sheets are set to be 0.35 mm or less, a Vickers hardness (test force 1 kg) of the sheets is set to be 150 to 400, and an average crystal grain size of the sheets is set to be 50 to 250 μm, a clearance of the mold is set to be 7% or more of a minimum sheet thickness of the sheet thicknesses of the electrical steel sheets and equal to or lower than 7% of a total sheet thickness of the electrical steel sheets, and a pressure that a sheet presser of the mold applies to the electrical steel sheets is set to be 0.10 MPa or more.

A punching method includes: punching out a plurality of electrical steel sheets in a stacked state by a mold, wherein sheet thicknesses of the electrical steel sheets are set to be 0.35 mm or less, a Vickers hardness (test force 1 kg) of the sheets is set to be 150 to 400, and an average crystal grain size of the sheets is set to be 50 to 250 μm, a clearance of the mold is set to be 7% or more of a minimum sheet thickness of the sheet thicknesses of the electrical steel sheets and equal to or lower than 7% of a total sheet thickness of the electrical steel sheets, and a pressure that a sheet presser of the mold applies to the electrical steel sheets is set to be 0.10 MPa or more.

An electromagnetic induction device comprises a closed magnetic circuit, without air gap, of which at least one first part is substantially rectilinear and surrounded by a sleeve, the sleeve being surrounded by an electrical conductor which comprises at least one metal sheet electrically insulated on at least one of its faces, wherein at least the first part of the magnetic circuit has a section of circular form.

A coil assembly for a magnetic actuator is described, the coil assembly comprising: —a tubular coil holder (100) comprising a first (110) and second open distal end (120); —the first open distal end comprising an outer circular rim (112) and an inner circular rim (114) separated by a circular groove (116); —the second open distal end comprising an outer circular rim (122); the tubular coil holder further comprising a central circular rim (130) arranged substantially halfway between the inner circular rim of the first open distal end and the outer circular rim of the second open distal end; —a coil (140) formed of a single wire (150) the coil comprising a first coil section (142) arranged in a first winding area (144) between the inner circular rim of the first open distal end and the central circular rim, and a second coil section (146) in a second winding area (148) between the central circular rim and the outer circular rim of the second distal end; the first coil section and the second coil section being wound about the tubular coil holder in opposite directions; whereby a first end (152) and a second end (154) of the single wire are arranged in the circular groove, the inner circular rim comprising a longitudinal groove (114.1) to extend the first aid and the second end of the single wire from the circular groove to the first winding area; the central circular rim composing a longindinal groove (130.1) to extend the single wire form the first winding area to the second winding area and vice versa; —an external connection (160) comprising a first conductor (162) and a second conductor (164); whereby an end of the first conductor is electrically connected to the first end of the single wire so as to form a first electrical connection (166) arranged in the circular groove and an end of the second conductor is electrically connected to the second end of the single wire so as to form a second electrical connection (168) in the circular groove and wherein the first and second conductor extend through the outer circular rim via a longitudinal groove (112.1) of the outer circular rim.

A coil assembly for a magnetic actuator is described, the coil assembly comprising: —a tubular coil holder (100) comprising a first (110) and second open distal end (120); —the first open distal end comprising an outer circular rim (112) and an inner circular rim (114) separated by a circular groove (116); —the second open distal end comprising an outer circular rim (122); the tubular coil holder further comprising a central circular rim (130) arranged substantially halfway between the inner circular rim of the first open distal end and the outer circular rim of the second open distal end; —a coil (140) formed of a single wire (150) the coil comprising a first coil section (142) arranged in a first winding area (144) between the inner circular rim of the first open distal end and the central circular rim, and a second coil section (146) in a second winding area (148) between the central circular rim and the outer circular rim of the second distal end; the first coil section and the second coil section being wound about the tubular coil holder in opposite directions; whereby a first end (152) and a second end (154) of the single wire are arranged in the circular groove, the inner circular rim comprising a longitudinal groove (114.1) to extend the first aid and the second end of the single wire from the circular groove to the first winding area; the central circular rim composing a longindinal groove (130.1) to extend the single wire form the first winding area to the second winding area and vice versa; —an external connection (160) comprising a first conductor (162) and a second conductor (164); whereby an end of the first conductor is electrically connected to the first end of the single wire so as to form a first electrical connection (166) arranged in the circular groove and an end of the second conductor is electrically connected to the second end of the single wire so as to form a second electrical connection (168) in the circular groove and wherein the first and second conductor extend through the outer circular rim via a longitudinal groove (112.1) of the outer circular rim.

A surface-mounted inductor including a coil having a wound part formed by winding a conductive wire and extended parts extended from an outer circumference of the wound part, a molded body containing the coil, constituted by a composite material containing a magnetic powder, and outer terminals connected to end portions of the extended parts disposed on a mounting surface. The wound part is contained within the molded body so that a winding axis is parallel to the mounting surface. The extended parts are extended toward the mounting surface side, each end portion of the extended parts are exposed from the surface thereof of the molded body. In the molded body, a density of a magnetic powder between the end portions of the extended parts on the mounting-side surface is lower than a density in the surface on the opposite side from the mounting surface.

A surface-mounted inductor including a coil having a wound part formed by winding a conductive wire and extended parts extended from an outer circumference of the wound part, a molded body containing the coil, constituted by a composite material containing a magnetic powder, and outer terminals connected to end portions of the extended parts disposed on a mounting surface. The wound part is contained within the molded body so that a winding axis is parallel to the mounting surface. The extended parts are extended toward the mounting surface side, each end portion of the extended parts are exposed from the surface thereof of the molded body. In the molded body, a density of a magnetic powder between the end portions of the extended parts on the mounting-side surface is lower than a density in the surface on the opposite side from the mounting surface.

A negative feedback inductor and a gate inductor are formed in different wiring layers of a substrate so as to be at least partially overlapped with each other in a plan view. When the lower wiring layer is thinner and the upper wiring layer is thicker, the negative feedback inductor Lc is formed in the lower wiring layer that is thinner.

A negative feedback inductor and a gate inductor are formed in different wiring layers of a substrate so as to be at least partially overlapped with each other in a plan view. When the lower wiring layer is thinner and the upper wiring layer is thicker, the negative feedback inductor Lc is formed in the lower wiring layer that is thinner.

An induction heater for a device for heating tobacco or aromatic herbs, in particular of the heat-not-burn type. The induction heater includes at least one inductor having at least one electrically insulating layer and at least one electrically conductive track fixed to the at least one electrically insulating layer. The at least one inductor is adapted to be arranged about a metal tube in which part of a cigarette can be inserted, and the metal tube is adapted to be heated by induction by the at least one inductor.