Abstract: A microwave furnace (10) of the type comprising a microwave source (14), coupled to an enclosure for the confinement of microwaves and for containing an object to be heated (12). An independently controllable alternate heating (20) is disposed in relation to the enclosure (12) to provide at least one of radiant and convective heating within the enclosure. The method comprises the steps of energizing the alternate heater (20) so as to generate heat substantially throughout the heating cycle of the furnace (10) and controlling the quanity of heat generated in the object y one or both of the microwaves and the alternate heater so as to provide a desired thermal profile in the object. A temperature sensor to measure the ambient temperature within the enclosure (12) can be provided and control circuit (54) responsive to the sensed temperature controls the quanity of heat generated in the object by the microwaves and the alternate heat so as to provide a desired thermal profile within the object.

Abstract: Disclosed is an AC/DC type microwave oven. The AC/DC type microwave oven comprises a rotatable inverter which inverts a DC power source to an AC power source by means of a rotational force, a high voltage transformer which receives a common power source or an AC power inverted by the rotatable inverter and outputs a higher voltage and a magnetron which is driven by the high voltage outputted from the high voltage transformer and radiates a microwave, and further comprises a control unit which controls the operation of the rotatable inverter so as to output a stable frequency. The rotatable inverter comprises a motor, a commutator driven by the motor and a plurality of brushes, which are respectively contacted with an outer surface of the commutator.

Abstract: An AC/DC type microwave oven has a function of managing an input power source. The AC/DC type microwave oven comprises a rotatable inverter which inverts a DC power source to an AC power source by a rotational force, a high voltage transformer which receives a common power source or an AC power inverted by the rotatable inverter and outputs a higher voltage, a magnetron which is driven by the high voltage outputted from the high voltage transformer and radiates a microwave and a power control unit for sensing a signal from a power selecting key and preventing the AC and DC power sources from being simultaneously inputted. Therefore, both of AC power and DC power are prevented from being simultaneously supplied to the microwave oven which could result in a malfunction, or an overload occurs in the electric components of the microwave oven. Therefore, only one input power of the common and DC power sources is selected and, the microwave oven is operated properly.

Abstract: A control system for a blind microwave radiation tool a workpiece is described. The controlled system automatically tunes the cavity containing the workpiece. The control system automatically controls the temperature of the workpiece according to a predetermined temperature versus time schedule. Control system automatically determines when the workpiece has reached a particular predetermined physical condition. To achieve these results the control system automatically monitors applied power, reflected power or current temperature and automatically controls the microwave cavity volume and shape and launch structure including antennae location, cavity short location, cavity diameter, coupling loop position, etc. in order to maintain the cavity in resonance and to determine when to exit without operator intervention.

Abstract: A control panel assembly of a microwave oven which is easy to use, including: a front panel section having first and second cooking mode single-functional buttons comprised of a plurality of single-functional buttons for first and second cooking modes of the microwave oven, and a slot formed on the middle portion of the front panel section between the first and second cooking mode single-functional buttons; a movable switch disposed on the front panel section which is moved laterally along the slot of the front panel section; and a mode shifting switch for shifting cooking modes to the first and second cooking modes by the movement of the movable switch, wherein the first and second cooking modes are automatically selected by the movement of the movable switch, and the cooking mode single-functional button of the selected mode is exposed outward for pressing by a user. Accordingly, by simply moving the movable switch in a lateral direction, the cooking modes of the microwave oven are automatically selected.

Abstract: Disclosed is a control panel of a microwave oven comprising a panel body, a timing device, a time control knob, and a power control knob assembly. The power control knob assembly has a pinion assembled with the power control shaft, a rack engaged with the pinion, and a knob installed slidably along a guiding recess formed on the panel body so as to move the rack linearly. As the knob is slide along the guide recess of the panel body of tie panel, the rack moved by the knob rotates the pinion. Accordingly, the output control shaft is rotated, and thereby the output power degree of the microwave is set. As described, knob of the power control knob assembly for controlling the output power of the microwave is linearly moved. Accordingly, the user can easily distinguish the power control knob from the time control knob.

Abstract: A microwave processing system comprising a microwave applicator and a microwave source. A microwave source generates a microwave field at an output frequency. A frequency of the microwave field in the elongated chamber and the output frequency of the microwave source are matched through the use of controlled feedback of critical material and process parameters.

Abstract: A power supply device for a non-linear load, especially a magnetron for microwave ovens, includes a resonant transformer. Using a fuzzy logic management unit, a level of a low voltage signal on the primary side of the transformer, a level of high voltage signal on the secondary side of the transformer, and a signal corresponding to the ambient temperature of the transformer are taken into account for the generation of a parameter for a control signal for controlling a switch positioned at the primary winding of the transformer. The power supply device makes it possible to reduce the size of the resonant transformer.

Abstract: A power supply cut-off apparatus of a microwave oven includes a switch box, which is pivotally opened and closed, and provided at a prescribed position of an outer panel. A power supply connection unit is provided inside of the switch box and connected detachably to three power supply wires of an electric cord. A fuse is detachably provided in fuse fixing portions disposed on one side of the power supply connection unit.

Abstract: A high frequency heating device having a switching member screwed into a screw hole formed in a flange and fixed to the exterior. When the exterior is fixed to the body, a through-hole formed at that portion in the rear plate of the body through which the switching member passes is too large for the switching member. Thus, while the switching member is fixable to the exterior, the switching member cannot be fixed to the body onto which the exterior is not mounted. Therefore, a high frequency heating device can be provided, wherein an exterior switch more surely keeps the power supply circuit open when the exterior is removed.

Abstract: A power supply for a CW magnetron, devoted for use in microwave heating equipment. A power supply according to the present invention (FIG. 1) has a high-voltage line transformer (1) with secondary winding (2) which is connected through a voltage doubling rectifier circuit to the magnetron cathode (4). The voltage-doubling rectifier circuit comprises a high-voltage diode (7) and a capacitor (3). The distinctive feature of the present invention is that the diode (7) of voltage doubler is connected in-series with the at least one thyristor-capacitor network (8) which is composed of a high-voltage thyristor which has its anode and cathode connected together with an additional capacitor (Cd) or with series connection of said capacitor with a resistor (Rs).

Abstract: A switching device is employed in a power supply for driving a magnetron with lower withstand voltage and better controllability. A high frequency heating apparatus comprises a power supply, a leakage transformer connected to the power supply, a first switching device connected in series to a primary coil side of the leakage transformer, a first capacitor, a series circuit of a second capacitor and a second switching device, a driving circuit having an oscillator for driving the first switching device and the second switching device, a rectifier connected to a secondary coil side of the leakage transformer, and a magnetron connected to the rectifier. With this configuration, voltage applied to the first switching device can be clamped, and at the same time, the OFF time can be freely adjustable by the effect of the second capacitor and the second semiconductor switching device.

Abstract: A microwave oven having a silent cooking mode and a method for operating the microwave oven are disclosed. The microwave oven has a magnetron driving section connected to a secondary winding of a high voltage transformer which receives an external power source via a primary winding thereof. A fan motor ventilates a cooking chamber of the microwave oven and a silent cooking mode selecting key selects the silent cooking mode. Voltage dividing section divides the voltage of the external power source. Switching section supplies the external power source to the fan motor at a normal cooking mode and supplies the external power source of which the voltage is divided by the voltage dividing section to the fan motor at the silent cooking mode. Control section controls the switching section in response to a key signal from the silent cooking mode selecting key. Accordingly, when the user selects the silent cooking mode, a noise generated from the fan motor is reduced remarkably.

Abstract: The invention relates to an apparatus and method for operating a turntable motor in a microwave oven. The inventive system includes a transformation of a commercial power supply into a lower voltage power source for application to the turntable motor when the turntable motor is operated in response to a control signal.

Abstract: A microwave oven comprises a main body, a cooking chamber and an electrical component compartment. The electrical component compartment contains a fuse housing which is mounted on a bracket to hold a fuse. Plastic coupling members are integrally mounted onto the fuse housing bracket, into which a fuse is inserted. Each coupling member includes a guide projecting integrally upwardly from the bracket. Both sides of the fuse housing contact respective ones of the guides. A protruding portion on the top of each guide forms a cam surface for spreading the guides apart, and a stop surface for preventing upward dislodgement of the fuse housing.

Abstract: A microwave oven includes a power cord for supplying electrical power to electrical components of the oven. Wires of the cord are connected to a first set of terminals of a switch mounted on a main body of the oven. Electrical power is conducted from the first set of terminals to a second set of terminals of the switch by means of conductors carried by an outer panel of the oven that can be removed from the main body. The second set of terminals are connected to electrical components of the oven. When the outer panel is removed from the main body, the first set of terminals is disconnected from the second set of terminals, and an electrically insulative cover is spring biased to a position covering the sets of terminals.

Abstract: A power supply for a microwave oven comprises a high-voltage transducer for receiving an AC voltage from a first coil and generating a high-voltage in a second coil; a high-voltage fuse having a first end connected to the second coil, and a grounded second end; a high-voltage diode for absorbing a surge-voltage grounded in parallel to the high-voltage condenser; and a magnetron connected to an output port of the high-voltage condenser, for radiating microwaves. The high-voltage fuse comprises an insulating member; a first fuse holder disposed in the insulating member; a second fuse holder having an annular ground ring opposed to the first fuse holder; a fuse body located between the first and second fuse holders; a lead wire electrically connected to the first fuse holder at one end thereof; and a fuse connection element joined to the other end of the lead wire.

Abstract: An improved method for controlling a power relay of a microwave oven which is capable of reducing the generation of sparking which occurs when the contact points of the power relay are separated, by turning off the power relay at a time (2n-1) .pi.+3/4.pi.during the "+" cycle and at a time 2n.pi.+3/4.pi. during the "-" cycle in the voltage phase or the current phase, for separating the contact points when the flow of the current is decreased, thus extending the life span of the relay. The method includes judging whether the power relay was previously turned off during the "+" cycle of the power voltage or during the "-" cycle of the power voltage when a clock signal of 50 Hz/60 Hz is inputted, and turning off the power relay after an apex of the "+" or "-" cycle of the power voltage after delaying the output time of a relay driving signal for a predetermined time in accordance with the judgement.

Abstract: A microwave oven includes a safety mechanism which automatically cuts off a supply of electric power to the oven when a panel of the oven housing has been removed, even if the power supply cord is still plugged in. The safety mechanism includes a switch disposed on the housing for cutting off the power. A cover for the switch is movable between a first position covering the switch, and a second position exposing the switch. The switch is biased to a power-cut-off position and the cover is biased to the first position. A structure of the panel is arranged to automatically move the cover to its second position, as well as to move the switch to a power-supply position, in response to the panel being in an assembled state. When the panel is removed, the switch automatically cuts off the electric power, and the cover moves to the first position covering the switch.

Abstract: A microwave oven includes a power cut-off safety switch which automatically cuts-off the supply of electric power to the oven if a housing panel is removed while the electric power supply cord is still plugged in. The switch is engaged by an extension of the housing panel which extends through a guide hole formed by another housing panel. The guide hole can have a non-planar shape to resist efforts to insert objects through the guide hole.

Abstract: A microwave oven includes a housing formed by relatively separable first and second panels. Electric switches are mounted on the first panel and are connected to respective wires of the power cord by the oven. Each switch includes a movable contact which moves away from a respective fixed contact when the panels are separated from one another, in order to automatically cut off the supply of electric power to the oven in the event that the worker forgets to unplug the power cord. When the panels are reconnected, the switches are automatically closed. Such automatic closing can be caused by magnetic force produced by magnets carried by the second panel. Alternatively, the automatic closing can be caused by screws carried by the second housing and which physically push respective movable contacts against their associated fixed contacts.

Abstract: A microwave oven includes a case forming a cooking chamber, and an outer panel mounted to the case. The outer panel is to be separated from the case when performing certain maintenance or repairs. Electrical terminals are mounted on the case and outer panel to perform the function of automatically disconnecting power to the oven in response to removal of the outer panel. A first arrangement of terminals can be provided for performing that function in the event of a removal of the outer panel in an upward direction. A second arrangement of terminals can be provided for performing that function in the event of a removal of the outer panel in a rearward direction.

Abstract: Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

Abstract: A microwave oven includes a cooking chamber, a tray disposed in the cooking chamber upon which food can be placed, and a magnetron for supplying high frequency waves to the cooking chamber. The microwave oven has a food-thawing mode and a food-cooking mode. In the thawing mode, the oven is capable of bringing food to different states of thawing in response to the selection of a specific food-thawing key. In the food-cooking mode, various cooking levels can be selected.

Abstract: A microwave oven has a food-receiving cavity and a magnetron for delivering microwave power to the cavity. The magnetron is supplied with a high voltage through a transformer, and a variable impedance is connected in series with the primary winding of the transformer. The resistive heating effect produced by primary current is utilized to heat the air in the oven cavity, and the magnitude of the impedance is variable to vary the output of the magnetron.

Abstract: An apparatus for controlling power of a microwave oven is disclosed in which the control thereof is easy and stable, and long-term durability is improved. The apparatus includes a control knob having a knob shaft to be inserted through a hole on a control panel, a coupler fixedly secured to the control knob shaft through the hole to be rotatably installed on the control panel together with the control knob, an annular projection integrally formed on one side of the coupler having several V-grooves formed along the peripheral surface of the annular projection, a resilient member, for instance, a wire or leaf spring, having a protrusion at a mid-position thereof, and a pair of pins for mounting the resilient member on the control panel. While controlling the power of the oven, the protrusion of the wire or leaf spring slides on the peripheral surface of the annular projection with resilient contact thereon, or remains resiliently fitted to any one of the V-grooves of the annular projection.

Abstract: Disclosed is an operational switch for a microwave oven using a pair of gears and a pair of micro switches in order for a magnetron and a heater of a microwave oven to operate. At the rear surface of a control panel, a first switch for turning on/off the magnetron and a first gear having a pair of pushing pieces for controlling the first switch are installed. At an edge of the first gear a second switch for controlling the heater is provided. A second gear for controlling the second switch is provided while meshing together with a power controlling gear of a timer body. A pair of pushing pieces are protrudingly formed on the surface of second gear. The first gear further includes a stopper and a pair of impeding pieces for limiting the rotation range and a pair of elastic pieces and a ring type guiding member for guiding the rotation.

Abstract: A high-illumination lighting system for microwave ovens which employs a small, low-voltage microwave-immune incandescent lamp located within the oven cavity, thereby utilizing up to the full 4.pi. steradians of emitted light. The lamp, which may be integrated into the oven cavity during manufacture or may be included in aftermarket ovens as a complete lamp module, preferably is located at the upper front of the oven in order to front-light the over contents. The lamp may be electrically connected to one of several existing oven power supplies, or alternatively, may be an aftermarket module powered by microwave energy within the oven cavity. In the latter case, a microwave antenna is connected to the lamp to supply operating power.

Abstract: There is provided a magnetron comprising a cold cathode having an electron emitting member which is formed linearly or as a plane on a substrate to emit electrons a subdivided anode disposed oppositely in parallel with the electron emitting member, the subdivided anode having cavity resonators formed therein at the side of the cold cathode, and a magnet which producing a magnetic field lying at right angles to an electric field applied between the cold cathode and the subdivided anode. There is also provided a microwave oven for dielectric-heating a substance to be heated by using the magnetron as a microwave supply source.

Abstract: An improved controller for a microwave oven capable of preventing it from an undesired heating caused by an erroneous operation thereof, which includes a heating member for generating heating energy; a power switch for controlling electric power supply to the heating member; a switch module including a plurality of switches for selecting a desired function; a microcomputer for outputting scanning signals having predetermined time differences to the switch module and for outputting a predetermined control signal in accordance with a key input signal outputted from the switch module; and a controller for controlling the power switch in accordance with control signals outputted from the microcomputer and a signal applied from the switch module, wherein the control signals includes a latch signal maintaining a predetermined state after the output signal of a switch is detected, while having the same level as a scanning signal outputted from a switch which is selected by an operation mode corresponding to scanning

Abstract: A microwave oven has a cooking time selecting unit and a cooking power selecting unit. The cooking time selecting unit has a first shaft which extends through a control panel and a first knob is mounted on the first shaft. The cooking power selecting unit has a second shaft which is disposed parallel to the first shaft and extends through the control panel. A second knob is mounted on the first shaft and has an outwardly open recess in which the first knob is freely rotatably disposed. A rotary power transmitter such as an idler gear or a timing belt interconnects the second knob and second shaft.

Abstract: A microwave oven includes a magnetron for performing a microwave cooking function, and a separate electric heater element for performing a grilling function. A single control knob on a control panel serves to activate the magnetron and heater element, as well as selecting an output power of the magnetron. By actuating that single knob a user can select cooking operations solely by microwaves only, or solely by the heating element, or by a combination of both. A separate knob on the control panel enables a cooking time to be selected.

Abstract: Disclosed is a microwave power controlling device having a reduced production cost and an improved assembling work efficiency by using a simple structure and the reduced number of components. A supporting stepped portion is formed on an inner surface portion of a control panel having a rotating through hole formed at a central portion thereof into which a knob axis for controlling the microwave power is inserted. An elastic piece and a pair of stoppers are formed on an upper surface of the supporting stepped portion. On an opposite surface of the supporting stepped portion, a microwave power controlling gear is mounted. The microwave power controlling gear has an engaging jaw for defining a rotating range thereof and a ring-shaped guide portion having plural notched grooves engaged with the elastic piece. The microwave power controlling gear is meshed with a coupling gear meshed with a microwave power controlling circuit gear of a timer body.

Abstract: The invention relates to a process for a uniform and fast heating of products by microwaves that are pulsed and introduced intermittently into the products, with the products to be treated, such as chemical or pharmaceutical products or foodstuffs, particularly ready-cooked meals, being conveyed by a continuously working endless conveyor belt through a treatment chamber in open or closed microwave-permeable trays and with the treatment chamber being equipped with microwave generator supply channels that are arranged in a vertical or inclined position relative to the conveyor belt. The line is operated at a microwave power profile that shortens the build-up time and breaking time of the microwave pulses, at a working frequency of 50 kHz that has an edge steepness of 2 microseconds, and with pulses the amplitudes of which have a rectangular form and the length of which is in the microseconds or milliseconds region.

Abstract: A power supply for a microwave range, which can control its own output voltage over a wide range of voltages by utilizing a voltage driving type switching element, and which includes a first transformer for driving a DC voltage, a switching element for driving the first transformer, a controller for supplying a switching signal which is pulse-width-modulated to the switching element, and a second transformer for transmitting the switching signal from the controller to the switching element. A buffer is coupled between the second transformer and the switching element for generating an amplified buffered switching signal, which maintains a constant DC voltage level and swing width so as to correctly drive the switching element.

Abstract: An automatic cooking appliance has a magnetron to cook the food. The cooking appliance has a dial, which is rotatable and capable of being pressed, on an operation panel thereof. A cooking mode in the menu is selected due to the rotation of the dial. The cooking mode is determined by pressing of the dial. The cooking appliance controls the magnetron in accordance with the determined cooking mode. This enables the dial to be used for multiple purposes to thereby save space on a control panel.

Abstract: A high-frequency heating device includes a power converter for converting an electric power from a commercial power source or the like into a high-frequency power, a step-up transformer having a high-voltage winding and a low-voltage winding, a magnetron receiving high-voltage and low-voltage outputs, a resonance circuit connected in series or parallel with the filament of the magnetron, and a control circuit. The control circuit controls the power converter so that the operation frequency of the power converter approximately coincides with the resonance frequency of the resonance circuit at the time of activating the power converter to thereby achieve a rapid start of the oscillation operation of the magnetron while suppressing a high voltage from taking place at the activation time to prevent the possible occurrence of the moding phenomenon.

Abstract: A high frequency heating apparatus such as microwave ovens includes an inverter circuit having a switching element and converting a commercial ac power supply to a high frequency power supply by controlling "on" and "off" periods of the switching element, a magnetron driven by the inverter circuit, a counter cumulatively counting an operating period of time and a deenergization period of time of the magnetron, and a compensator for compensating an "on" period of the switching element based on a count value of the counter so that an input power to the inverter circuit is rendered constant.