| 摘要 |
PURPOSE:To adjust the electric power applied to a load with a simple structure by providing a movable magnetism shielding plate made of a magnetic nonconductor or a nonmagnetic conductor to change the magnetic coupling between a heating coil and the load. CONSTITUTION:A movable magnetism shielding plate 7 to change the magnetic coupling is provided between a heating coil 2 and a load 5. The magnetism shielding plate 7 is made of ferrite which is a magnetic nonconductor, but it may be made of a nonmagngtic conductor. When a power switch is turned on, a driving section 4d is operated, an inverter section 3 is driven at the preset value, a pot 5 which is a load is heated. When a power setting lever 6a is moved, the magnetism shielding plate 7 is moved, the area of the magnetism shielding plate 7 located above the heating coil 2 is changed, the degree that the magnetic flux generated by the heating coil 2 is absorbed by the magnetism shielding plate 7 made of ferrite is changed. The degree of the magnetic coupling between the heating coil 2 and the load 5 is thereby changed, the power fed to the pot 5 is adjusted. |
