Abstract: An induction heating device for controlling the temperature distribution in an electrically conductive material, or susceptor, when heated by induced eddy currents in the material. A non-electrically conductive material can be heated in a controlled manner by placing the material near to the susceptor. Variable power is applied to multiple induction coil sections wound around the length of the susceptor from a power source by one or more switching circuits. The coil sections can be overlapped or counter-wound between adjacent coil sections, or provided power in a cascaded manner, to achieve desired temperature distributions in the susceptor. A control circuit is used to control the power applied to each coil section and the output of the power source. By placing a non-electrically conductive material near to the susceptor the material can be heated in a controlled manner.

Abstract: Apparatus for inductively melting a quantity of metal without a container includes a first induction coil having a plurality of turns defining a volume for receiving a quantity of metal, the first induction coil being adapted to exert a force on the metal, a second induction coil having a plurality of turns at substantially right angles to the turns of the first induction coil, the second induction coil, being disposed within said volume coaxial with the first induction coil. Both the first and second induction coils have connectors thereon for connecting the coils to at least one power supply for energizing the first and second induction coils. A support is provided for supporting the metal from below, and has an opening through it. The support includes a raised segmented rim around substantially its entire periphery. The support is maintained at a preselected temperature. In an alternate embodiment, structure is also provided for imparting rotational motion to the support.