Abstract: Preferred embodiments of the present invention provide systems and methods that automatically correct the desired on-time of switching elements as the resonant frequency changes, so as to maintain the correct proportional value.

Abstract: Preferred embodiments of the present invention provide systems and methods that automatically correct the desired on-time of switching elements as the resonant frequency changes, so as to maintain the correct proportional value.

Abstract: Power switching systems often benefit from controlling the instant at which the power devices change state so as to minimize dissipation in these devices. Such systems often require fairly tight tolerances on reactive components and a relatively narrow frequency operating range to be certain these switching times occur as intended. This invention defines a system that can adapt the required switching instant over very wide changes in the reactive components.

Abstract: A circuit apparatus for providing an AC voltage to a load. The apparatus may include: a first, second, third and fourth switch, wherein the first switch is connected between a first node and a first terminal of the second switch and the fourth switch is connected between a second node and a first terminal of the fourth switch; a voltage source, wherein the voltage source is electrically connected between the first node and the second node; a resistive divider connected across the voltage source; a first resistor connected across the first switch a second resistor connected across the third switch; first connecting means for configurably connecting a second terminal of the second switch to the second node; second connecting means for configurably connecting a second terminal of the third switch to the first node; and third connecting means for configurably connecting the second terminal of the second switch in series with the second terminal of the third switch.

Abstract: In one aspect, the invention provides a power system for providing power to a load.

Abstract: Power switching systems often benefit from controlling the instant at which the power devices change state so as to minimize dissipation in these devices. Such systems often require fairly tight tolerances on reactive components and a relatively narrow frequency operating range to be certain these switching times occur as intended. This invention defines a system that can adapt the required switching instant over very wide changes in the reactive components.

Abstract: Switches (such as FET's and other devices) are often used in circuits to generate an AC signal from a DC supply input. There are times when the supplied DC voltage is greater than desired for the ratings of the switches that can or must be used. There are also times when there may be voltage surges or other transient high voltage conditions for which it is desired to have greater margin between the voltage applied and the switch ratings. The circuit described applies across any of the switches a maximum of one half of the supplied DC voltage. The circuit may also be operated in a linear mode for use with analog signals.

Abstract: In one aspect, the present invention provides a consumer appliance that uses RF energy to heat foods stored in a container that is suitable for RF heating.

Abstract: When a power system experiences a disruptive event, conditions may exist that threaten the survival of power devices used in the system. Embodiments described herein provide an improved means of protecting these devices under such circumstances.

Abstract: Preferred embodiments of the present invention provide systems and methods that automatically correct the desired on-time of switching elements as the resonant frequency changes, so as to maintain the correct proportional value.

Abstract: Power switching systems often benefit from controlling the instant at which the power devices change state so as to minimize dissipation in these devices. Such systems often require fairly tight tolerances on reactive components and a relatively narrow frequency operating range to be certain these switching times occur as intended. This invention defines a system that can adapt the required switching instant over very wide changes in the reactive components.

Abstract: Switches (such as FET's and other devices) are often used in circuits to generate an AC signal from a DC supply input. There are times when the supplied DC voltage is greater than desired for the ratings of the switches that can or must be used. There are also times when there may be voltage surges or other transient high voltage conditions for which it is desired to have greater margin between the voltage applied and the switch ratings. The circuit described applies across any of the switches a maximum of one half of the supplied DC voltage. The circuit may also be operated in a linear mode for use with analog signals.

Abstract: An induction furnace, according to one embodiment of the invention, includes an induction heating system and a chamber that comprises a quartz cylinder, a top cover for sealing the top end of the cylinder, and a bottom cover for sealing the bottom end of the cylinder. The induction heating system includes a power supply and a coil. The coil surrounds the chamber. Contained within the chamber is a susceptor that is susceptable to induction heating. Also contained in the chamber is a thermal insulator that is disposed between the susceptor and the inner walls of the chamber. The insulator includes a fused quartz container in which the susceptor and the workpiece are contained.

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply.

Abstract: A low leakage inductance, versatile RF transformer with multiple input/output voltage ratios. The transformer has many applications. For example, and not by way of limitation, the transformer can be used with switching power supplies, RF induction power supplies, and RF plasma power supplies. The efficiency of the transformer is on the order of 99% to 99.7%. These efficiencies have been measured at power levels of 3 kilowatts (KW) to 10 KW.

Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises a susceptor and a carrier. The carrier and susceptor are blended with one another and form a mixture, preferably a uniform mixture. The susceptor is present in an amount effective to allow the susceptor composition to be heated by RF energy. In a preferred embodiment, the susceptor also functions as an adhesive. The susceptor is an ionic or polar compound and acts as either a charge-carrying or an oscillating/vibrating component of the susceptor composition. The susceptor generates thermal energy in the presence of an RF electromagnetic or electrical field (hereafter RF field).

Abstract: An RF power supply that is capable of tracking rapid changes in the resonant frequency of a load and capable of quickly responding to varying load conditions so as to deliver the desired amount of power. The present invention also provides an RF power supply capable of delivering a wide range of power over a broad frequency range to a load that is remotely located from the power supply.

Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises at least one ionomer and a polar carrier. The ionomer and polar carrier are blended with one another and form a mixture, preferably a uniform mixture. The ionomer and polar carrier are present in an amount effective to allow the susceptor composition to be heated by RF energy. Also disclosed are RF induction heating systems.

Abstract: An induction heating system that can be used to braze metals and that overcomes many of the disadvantages of conventional brazing systems. The induction heating system improves quality and lowers production cost for many brazing requirements. The system is designed to quickly, accurately and cost effectively heat individual parts, and to replace flame brazing procedures and batch vacuum furnaces. Because the system can braze parts in an inert atmosphere or in no atmosphere (e.g., in a vacuum), no flux or acid cleaning bath is necessary and oxidation on the part is eliminated. Further, by including a gas quenching feature, the system prevents the annealing of parts and produces high quality brazed parts that meet desired hardness specifications.

Abstract: A susceptor composition that can bond two or more layers or substrates to one another and that can be used to coat or cut a substrate. The susceptor composition is activated in the presence of radio frequency (RF) energy. In one embodiment, the susceptor composition of the present invention comprises a susceptor and a carrier. The carrier and susceptor are blended with one another and form a mixture, preferably a uniform mixture. The susceptor is present in an amount effective to allow the susceptor composition to be heated by RF energy. In a preferred embodiment, the susceptor also functions as an adhesive. The susceptor is an ionic or polar compound and acts as either a charge-carrying or an oscillating/vibrating component of the susceptor composition. The susceptor generates thermal energy in the presence of an RF electromagnetic or electrical field (hereafter RF field).