A system for the production of a polycrystalline silicon product is disclosed. The system includes a reaction chamber, a susceptor, an induction unit, and a plurality of energy sources. The reaction chamber has a reactor wall, and the susceptor encircles the reactor wall. The induction heater surrounds the susceptor, and has multiple induction coils for producing heat in the susceptor. The coils are grouped into a plurality of zones. The plurality of energy sources supply electric current to the coils. Each energy source is connected with the coils of at least one zone.

A system for generating an asymmetric magnetic field. The system includes a drive circuit and a stacked winding structure coupled to the drive circuit. The stacked winding structure includes a plurality of winding layers. The plurality of winding layers includes a first winding layer including a first conductive winding having first turns and a second winding layer including a second conductive winding having second turns ion. The plurality of winding layers is arranged to produce a first magnetic field at a first side of the stacked winding structure and a second magnetic field at a second side of the stacked winding structure when the drive circuit electrically drives the plurality of winding layers. The first magnetic field is greater than the second magnetic field.

A system for generating an asymmetric magnetic field. The system includes a drive circuit and a stacked winding structure coupled to the drive circuit. The stacked winding structure includes a plurality of winding layers. The plurality of winding layers includes a first winding layer including a first conductive winding having first turns and a second winding layer including a second conductive winding having second turns ion. The plurality of winding layers is arranged to produce a first magnetic field at a first side of the stacked winding structure and a second magnetic field at a second side of the stacked winding structure when the drive circuit electrically drives the plurality of winding layers. The first magnetic field is greater than the second magnetic field.

The invention relates to a method for monitoring the temperature of the sleeve part of a tool holder, which sleeve part is inserted into the induction coil of a contraction device, wherein the instantaneous inductance of the induction coil is measured during the inductive heating and the current supply to the induction coil is influenced if the instantaneous inductance approaches, reaches, or exceeds a specified value.

The invention relates to a method for monitoring the temperature of the sleeve part of a tool holder, which sleeve part is inserted into the induction coil of a contraction device, wherein the instantaneous inductance of the induction coil is measured during the inductive heating and the current supply to the induction coil is influenced if the instantaneous inductance approaches, reaches, or exceeds a specified value.

An induction heating device for a metal strip includes a first induction coil member and a second induction coil member provided in parallel with a metal strip across the metal strip that travels in a longitudinal direction, provided to protrude from the metal strip, and provided so as not to overlap each other in the traveling direction of the metal strip, and a magnetic core member provided between the first induction coil member and the second induction coil member, and provided to cover a large area of an end portion in the sheet width direction of the metal strip on the side of each of the first induction coil member and the second induction coil member, and cover a small area of the end at a center portion between the first induction coil member and the second induction coil member.

An induction heating device for a metal strip includes a first induction coil member and a second induction coil member provided in parallel with a metal strip across the metal strip that travels in a longitudinal direction, provided to protrude from the metal strip, and provided so as not to overlap each other in the traveling direction of the metal strip, and a magnetic core member provided between the first induction coil member and the second induction coil member, and provided to cover a large area of an end portion in the sheet width direction of the metal strip on the side of each of the first induction coil member and the second induction coil member, and cover a small area of the end at a center portion between the first induction coil member and the second induction coil member.

An apparatus for bending a composite tube that includes an induction coil. Induction coil includes multiple turns and the turn-to-turn spacing changes at least once along the length of the induction coil. There is a heating element positioned near the induction coil and the induction coil is configured to cause the heating element to increase in temperature.

An apparatus for bending a composite tube that includes an induction coil. Induction coil includes multiple turns and the turn-to-turn spacing changes at least once along the length of the induction coil. There is a heating element positioned near the induction coil and the induction coil is configured to cause the heating element to increase in temperature.

Provided are an apparatus and a method of detecting an error in the apparatus. The apparatus includes an image former and an induction heating fusing device. The image former forms an image. The induction heating fusing device fuses the image formed by the image former onto paper. Whether the apparatus has an error is determined by limiting a current applied to a resonance circuit included in the induction heating fusing device to less than a certain level.