Abstract: The present invention provides a method for cutting an electromagnetic steel with a fiber laser, a method for producing an electromagnetic steel component wherein deterioration of magnetic properties is minimized and a rust-preventive effect is endowed, and a method for fabricating a core from the electromagnetic steel component cut by the fiber laser wherein an occurrence of varnish pool is suppressed. According to the present invention, an electromagnetic steel component is obtained by irradiating and cutting the electromagnetic steel sheet with a fiber laser while spraying an assist gas comprising an oxygen concentration of at least 50 volume percent, wherein the electromagnetic steel component is formed with an oxide film for preventing the occurrence of rust and minimizing degradation of magnetic properties to be caused by the heat of the fiber laser. The degraded magnetic properties of the electromagnetic steel component can be restored by the subsequent annealing treatment.

Abstract: The present invention provides a current transformer module that can achieve downsizing and keeping the creepage distance of insulation simultaneously. The current transformer module 12 according to the present invention comprises a current transformer 10 and a casing 80 for housing the current transformer, wherein the current transformer includes a resin-made bobbin 20 with a through hollow section 21 and a core 30 having legs 42 inserted at least into the hollow section, the bobbin having a primary coil 26 and a wire-wound secondary coil 27 on the outer periphery of the hollow section, wherein the bobbin has insulation walls 22, 24 between the primary coil and the secondary coil wherein the insulation wall has recesses 23,25, and wherein the casing are provided with protrusions 83, 87 adapted to fit into the recesses.

Abstract: The present invention provides a current transformer having excellent temperature characteristics and realizing high-precision adjustment of the output voltage via gap adjustment and small tolerance, and a method for manufacturing the same. The core component for current transformers of the present invention, comprises an E-type core 40 formed of an electromagnetic steel sheet and having three legs 41, 42, 41 extending substantially parallel to each other and a connecting part 43 connected at each end of the legs, and an I-type core 50 formed of an electromagnetic steel sheet and having the same length as the connecting portion, the I-type core being placed on and bonded to the connecting part of the E-type core to form a single-piece core component.

Abstract: The present invention provides a current transformer module that can prevent the primary coil from being lifted or dropped and prevent the bobbin from being cracked when the primary coil is inserted into the bobbin. The current transformer module 12 of the present invention comprises a current transformer 10 including a resin-made bobbin 20 and a core 50 mounted on the bobbin, wherein the bobbin has a U-shaped primary coil 30 disposed in a primary coil through-hole 40 and a wire-wound secondary coil 27, and a casing 80 for housing the current transformer, wherein the primary coil is a U-shaped pin having a pair of legs 32, 32 and a U-shaped bent portion 31 for connecting the legs, and the casing has a concaved contact area 82 positioned opposite the U-shaped bent portion of the primary coil to prevent the primary coil from falling out.