| 摘要 |
PURPOSE:To realize an efficient rise in temperature of an iron core by a method wherein, when the core formed of amorphous magnetic alloy thin plates is excited so that the temperature thereof is raised by heating for annealing, the frequency of an exciting high-frequency current made to flow through a coil is varied so as to increase the generation loss of the core. CONSTITUTION:A wound core 11 is formed by winding a belt-shaped amorphous magnetic alloy thin plate 12 in a rectangular form. A transformer coil 13 and temporarily-wound coils 14 through which an exciting high-frequency current is made to flow are wound before annealing is applied. When the wound core 11 is annealed, the temporarily-wound coils 14 are connected onto the high-frequency AC power source 16 side by a switch 15, a voltage is regulated by a voltage regulator 18, and the exciting high-frequency current is made to flow through the temporarily-wound coils 14. Then an eddy current flows through the wound core 11, a Joule heat is generated thereby, and the temperature of the core rises. Since an iron loss is reduced when the temperature rises above 300 deg.C, the excitation frequency of the current supplied to the temporarily- wound coils 14 is turned t=high by an inverter device 19, and thereby the temperature is raised to 400 deg.C and kept thereat for a prescribed period of time. |
