ABSTRACT
Since the ferrite magnetic core is located in the vicinity of the copper tube, a part of the magnetic flux links to the copper tube and generates in-plane eddy current. This tends to reduce the efficacy. We concentrate on the relative location d between copper tube and magnetic core. Fig.3 shows the efficacy dependence on the relative location d. In this study 92 LPW can be achieved when d /L is 7%. (L is the length of ferrite core and d is the protrusion length from copper tube end.) At this location eddy current is reduced appropriately. In this experiment we fix the location of copper tube and change the location of ferrite core with coil. This means that the location of coil and ferrite is closer to the bulb top with increasing value of d. We assume that too big d makes inappropriate coupling condition between plasma and induction coil. So there is an optimum d value in Fig. 3.
