Abstract: A control system for controlling the heating of a product in a dielectric oven comprises at least one dielectric heating circuit including an electromagnetic energy source, such as a triode vacuum tube, having an anode and a resonant circuit including at least one inductor and at least a pair of capacitors. Each capacitor includes two capacitor plates and one of these capacitor plates is moveable, such that each pair of capacitors forms a variable capacitor in which the product to be heated is a dielectric. The system also includes at least one ammeter for measuring actual anode current at the anode. A motor is used to increase or decrease a distance between the plates of at least one of said capacitors, thereby adjusting the electromagnetic energy delivered to the product. A processor receives ammeter measurements, whereby the distance between the pair of capacitor plates is adjusted to increase or decrease the actual anode current.

Abstract: A removable tray holds a product for heating in a dielectric oven. The tray comprises at least one wall defining an interior, wherein the at least one wall is made from a non-electrically conductive material, such as a polycarbonate resin having a thickness in a range of about 0.08 to 0.09 inches (about 2.03 to 2.29 mm). The at least one wall includes at least a first and a second electrode. Each of the electrodes comprises a first portion and a second portion, wherein the first portion is separated from the tray interior by a thickness of polycarbonate resin in a range of about 0.01 to 0.03 inches (about 0.25 to 0.76 mm). The first portions bracket the product, are substantially parallel to each other, and are encased within the at least one wall. Each of the second portions has an exposed area which when the tray is placed in the oven is coupled with an electromagnetic energy source to produce an electromagnetic field between the electrodes.

Abstract: A control system for controlling the heating of a product in a dielectric oven comprises at least one dielectric heating circuit including an electromagnetic energy source, such as a triode vacuum tube, having an anode and a resonant circuit including at least one inductor and at least a pair of capacitors. Each capacitor includes two capacitor plates and one of these capacitor plates is moveable, such that each pair of capacitors forms a variable capacitor in which the product to be heated is a dielectric. The system also includes at least one ammeter for measuring actual anode current at the anode. A motor is used to increase or decrease a distance between the plates of at least one of said capacitors, thereby adjusting the electromagnetic energy delivered to the product. A processor receives ammeter measurements, whereby the distance between the pair of capacitor plates is adjusted to increase or decrease the actual anode current.

Abstract: A removable tray holds a product for heating in a dielectric oven. The tray comprises at least one wall defining an interior, wherein the at least one wall is made from a non-electrically conductive material, such as a polycarbonate resin having a thickness in a range of about 0.08 to 0.09 inches (about 2.03 to 2.29 mm). The at least one wall includes at least a first and a second electrode. Each of the electrodes comprises a first portion and a second portion, wherein the first portion is separated from the tray interior by a thickness of polycarbonate resin in a range of about 0.01 to 0.03 inches (about 0.25 to 0.76 mm). The first portions bracket the product, are substantially parallel to each other, and are encased within the at least one wall. Each of the second portions has an exposed area which when the tray is placed in the oven is coupled with an electromagnetic energy source to produce an electromagnetic field between the electrodes.

Abstract: A dielectric oven for heating a product with a tray includes a housing having an access, wherein the housing defines a heating cavity. The oven includes an oven liner which substantially conforms to the interior shape of the heating cavity and forms a liner cavity within the heating cavity. The liner is made from a non-electrically conductive material which may have a low dielectric constant, a low dielectric loss tangent, and a melting point of at least about 225.degree. F. (107.degree. C.). The liner forms a vaportight boundary between the liner cavity and the heating cavity. The liner material may be a thermoplastic resin selected from the group consisting of polysulphone, polyester, and polycarbonate resins. The liner material may be reinforced with, for example, glass fibers, such as in fiberglass reinforced polyester resin. The housing and the liner may have at least one air intake port and at least one exhaust port. At least a pair of contacts may project into the interior of the oven liner.