Mitsubishi Denki Kabushiki Kaisha

Toyohiko Kiyohara

Yuji Haraguchi

Kazuya Toi

Takayuki Asoh

An arc control apparatus for a DC arc furnace provides an additional magnetic field which prevents a discharged arc from shifting outward at an arc generating point due to the influences of a magnetic field generated by a feeder circuit, thus directing the arc discharge vertically downward. The arc control apparatus includes an arc furnace in which an object to be melted is disposed. A movable electrode is disposed in the arc furnace for movement relative to the object. A feeder circuit including a power supply and a feeding conductor is connected to the movable electrode and the arc furnace for supplying a voltage therebetween from the power supply through the feeding conductor to generate an arc whereby the object is dissolved. An auxiliary coil is disposed outside and in the vicinity of the arc furnace and connected to the feeder circuit for generating a counter magnetic field in a direction to cancel a magnetic field which is generated at a point of generation of the arc by means of the feeder circuit.

Apparatus for controlling arc deflection in an arc furnace

Thyristor with self-centering housing means

A light triggered thyristor device is improved by providing a light guide having a taper portion and acting to condense incident light while being constructed so as to achieve total internal reflection of the light passing therethrough. With this construction, the exit end of the light guide, as well as the light receiving portion of the thyristor, can be reduced in size.

Growing community of inventors

Tokyo, Japan

Toyohiko Kiyohara