A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; energizing a primary inductive coil within the chamber to heat the mold via radiation from a susceptor, wherein the resultant electromagnetic field partially leaks through the susceptor coupled to the chamber between the primary inductive coil and the mold; determining a magnetic flux profile of the electromagnetic field; sensing a magnetic flux leakage past the susceptor within the chamber; generating a control field from a secondary compensation coil coupled to the chamber, wherein the control field controls the magnetic flux experienced by the cast part; and casting the material within the mold under the controlled degree of flux leakage.

A method of controlling an inductive heating circuit, having a varying load, to seal a packaging material is provided. The method comprises generating AC power of at least two frequencies on at least one inductor in the inductive heating circuit; determining the resulting phase shift in the inductive heating circuit from the current generated at the at least two frequencies; determining the impedance of the inductive heating circuit for each of the at least two frequencies; determining a load characteristics of the inductive heating circuit based on the relationship between the determined impedance and the determined phase shift; determining an impedance operating range; and selecting an AC output frequency for an induction power generator based on the load characteristics which results in the least amount of phase shift from a set ideal value and which is associated with an impedance that is within the impedance operating range.

A method of controlling an inductive heating circuit, having a varying load, to seal a packaging material is provided. The method comprises generating AC power of at least two frequencies on at least one inductor in the inductive heating circuit; determining the resulting phase shift in the inductive heating circuit from the current generated at the at least two frequencies; determining the impedance of the inductive heating circuit for each of the at least two frequencies; determining a load characteristics of the inductive heating circuit based on the relationship between the determined impedance and the determined phase shift; determining an impedance operating range; and selecting an AC output frequency for an induction power generator based on the load characteristics which results in the least amount of phase shift from a set ideal value and which is associated with an impedance that is within the impedance operating range.

A high frequency power supply system provides highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactors with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; energizing a primary inductive coil within the chamber to heat the mold via radiation from a susceptor, wherein the resultant electromagnetic field partially leaks through the susceptor coupled to the chamber between the primary inductive coil and the mold; determining a magnetic flux profile of the electromagnetic field; sensing a magnetic flux leakage past the susceptor within the chamber; generating a control field from a secondary compensation coil coupled to the chamber, wherein the control field controls the magnetic flux experienced by the cast part; and casting the material within the mold under the controlled degree of flux leakage.

A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; energizing a primary inductive coil within the chamber to heat the mold via radiation from a susceptor, wherein the resultant electromagnetic field partially leaks through the susceptor coupled to the chamber between the primary inductive coil and the mold; determining a magnetic flux profile of the electromagnetic field; sensing a magnetic flux leakage past the susceptor within the chamber; generating a control field from a secondary compensation coil coupled to the chamber, wherein the control field controls the magnetic flux experienced by the cast part; and casting the material within the mold under the controlled degree of flux leakage.

An induction coil structural unit has an induction coil into which a sleeve portion of a tool holder can be inserted. In order to increase a degree of automation, a defined-preset test current is applied to the induction coil even before the beginning of an inductive heating process, a time/current curve is determined for the current and the inserted sleeve portion is recognized. Heating parameters are established for the sleeve portion and the inductive heating process is started on the basis of the heating parameters. The inductive heating process is interrupted at least once and, during the interruption, a defined-preset check current is applied and a further time/current curve for the sleeve portion is determined for this check current. A decision is made on the basis of the further time/current curve of the check current whether the heating process is continued or permanently ended.

An induction coil structural unit has an induction coil into which a sleeve portion of a tool holder can be inserted. In order to increase a degree of automation, a defined-preset test current is applied to the induction coil even before the beginning of an inductive heating process, a time/current curve is determined for the current and the inserted sleeve portion is recognized. Heating parameters are established for the sleeve portion and the inductive heating process is started on the basis of the heating parameters. The inductive heating process is interrupted at least once and, during the interruption, a defined-preset check current is applied and a further time/current curve for the sleeve portion is determined for this check current. A decision is made on the basis of the further time/current curve of the check current whether the heating process is continued or permanently ended.

A heating device for removing snow or ice that accumulates in between a moving-point train track rail and a fixed train track rail consists of an induction coil, a holding case, and a mounting tray. The induction coil is positioned within the holding case which is then positioned on the mounting tray. For optimal performance, the mounting tray is positioned adjacent a planar bottom surface of both the fixed train track rail and the moving-point train track rail. The eddy current field of the induction coil excites the atoms within the steel which then results in elevated temperatures. The heat radiated from the fixed train track rail and the moving-point train track rail removes any accumulated snow or ice.

A process for directional solidification of a cast part comprises energizing a primary inductive coil coupled to a chamber having a mold containing a material; energizing a primary inductive coil within the chamber to heat the mold via radiation from a susceptor, wherein the resultant electromagnetic field partially leaks through the susceptor coupled to the chamber between the primary inductive coil and the mold; determining a magnetic flux profile of the electromagnetic field; sensing a magnetic flux leakage past the susceptor within the chamber; generating a control field from a secondary compensation coil coupled to the chamber, wherein the control field controls the magnetic flux experienced by the cast part; and casting the material within the mold under the controlled degree of flux leakage.