Abstract: A device of detecting an abnormal state of a microwave oven having relays, a high voltage transformer, and a magnetron, including a voltage sensing part connected between the high voltage transformer and the magnetron to sense a voltage applied to the magnetron's both terminals; and a control part receiving the voltage between the magnetron's terminals from the voltage sensing part to determine an unloaded state where nothing is in a cooking chamber or an overheated state of the magnetron or the cooking chamber, and when determining that the oven is in the abnormal state, turning off the relays to stop the operation of the magnetron; and a method of detecting an abnormal state of a microwave oven including the steps of driving a magnetron to perform a user-selected cooking operation; detecting a voltage between the magnetron's both terminals; computing an average voltage by averaging the voltage between the magnetron's terminals; detecting an abnormal state by comparing the average voltage to a reference volt

Abstract: A wall-mounted microwave oven and a control method for controlling a hood motor are provided. Here, the wall-mounted microwave oven having a main body forming a cavity for accommodating foods to cook, a casing enclosing the main body and forming a hood duct having an inlet located on a bottom area and an outlet located on an upper area, a hood fan installed in the hood duct, and a hood motor driving the hood fan, includes an inverter part for controlling the frequency of a supply current supplied from an external electrical power source to the hood motor, and a microcomputer for controlling the speed of the hood motor by transmitting a control signal to the inverter part, based on an external control signal. Thus, the size of the hood motor can be reduced, thus reducing a cost. Also, since the speed of the hood fan can be varied, ventilation and exhaust are performed within an optimal time to thereby seek conveniences of users.

Abstract: Disclosed is a wall mounted microwave oven including a body forming a cavity for accommodating the food to be cooked, a casing enclosing said body and having an inlet port and an outlet port respectively at the bottom part and on the top part thereof, to form a hood duct, and a hood fan being installed within said hood duct, comprising: a first switching part disposed on a main power source line interconnecting said hood fan and a power source, for switching on or off power transmission to said hood fan, a sensing switching part disposed on a sub power source line connected in parallel to said main power source line, and being turned automatically on or off depending on ambient temperature to switch on said hood fan when ambient temperature is over a predetermined temperature, and a second switching part disposed on said sub power source line, and being turned manually on or off to allow said hood fan to be switched of during said sensing switching part is on.

Abstract: The magnetron driving control apparatus of a microwave oven and a method thereof by which voltage at output side of a high voltage transformer and voltage of a magnetron are detected by a first and second voltage detecting units and a cooking process status is discriminated according to changes of the voltage at the output side of the high voltage transformer and the voltage of the magnetron to control the driving of the magnetron, such that foodstuff is optimally cooked and an automatic cooking is performed without installment of high priced sensors to thereby reduce the manufacturing cost.

Abstract: A magnetron driving control apparatus of a microwave oven and a method thereof by which a magnetron is continuously driven when an output level selectively input by a user belongs to a continuous driving output range, and when the output level exceeds an established time, the magnetron is intermittently driven according to a predetermined period to allow a high voltage transformer to cool by itself during the period the driving of the magnetron is stopped, thereby preventing the high voltage transformer from becoming over-heated and avoiding the high voltage transformer from becoming larger in size to decrease a heat generated by an electric resistance.

Abstract: A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

Abstract: A metallic supplementary pot having superior heat conductivity is newly provided which is attached in the conventional nonmetallic specialized pot which is placed on a turn table mechanism of the microwave oven. When bread is made in the microwave oven, the supplementary pot containing material is attached in the specialized pot before cooking, and the specialized pot is attached to the drive shaft of the turn table mechanism in the oven cavity. Since the tip of the drive shaft is fit into the supplementary pot in this case, a vane member is attached to the drive shaft in the supplementary pot. When cooking is started, the vane member is turned with the rotation of the drive shaft and the material is kneaded into dough. Thereafter, the dough is heated uniformly and in a short time in the supplementary pot, and bread is completed.

Abstract: Method and microwave oven for controlled boiling of a foodpiece. The foodpiece is heated rapidly into reliable boiling by a supply of maximum microwave power, thereafter a desirable degree of boiling (H.sub.eb) is carried out during a predetermined boiling time (T.sub.b) while controlling the supplied microwave power level dependent on feed-back information (HUM) from a sensor. The boiling procedure is carried out fully automatically with consequently increased user security, decreased energy consumption and improved boiling quality.

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 an electric power supply shut-off mechanism for cutting off the supply of electric power when the housing is disassembled for repair while an electric power cord remains plugged into an electric outlet. A sensor in the form of a light sensitive semiconductor and/or a piezoelectric crystal senses when panels of the oven housing are removed and thereupon causes a controller to actuate a solenoid which deactivates a safety switch for cutting off the supply of electric current.

Abstract: In a relay driving apparatus and method for a microwave oven, a high relay driving voltage is applied at an initial relay driving time to reduce the operating time deviation between relay parts and the high relay driving voltage is lowered to a normal relay driving voltage through a damp resistance if contact points of a relay switch are coupled, thereby implementing a fix crossing. Therefore, rush current is minimized during relay operation, thereby preventing the fixation of the contact points of a relay switch and the generation of noises due to vibration.

Abstract: In a microwave generator apparatus including a magnetron having a filament and an anode and generating a microwave, a filament power source supplies a filament power to the filament of the magnetron, and an anode power source applies an anode voltage between the filament and the anode of the magnetron. Then a parasitic oscillation detecting circuit detects a parasitic oscillation voltage superimposed on the microwave generated by the magnetron, and a filament power controller, in response to the parasitic oscillation voltage detected by the parasitic oscillation detecting circuit, controls the filament power source to control the filament power so that the parasitic oscillation voltage is made smaller.

Abstract: In an automatic cooking controlling apparatus and method for a cooker, the apparatus includes a turntable installed within a chamber of the cooker for placing a to-be-cooked object thereon, an infrared filter for filtering only the infrared wavelength bands reflected from the to-be-cooked object, an infrared adjusting lens means for adjusting the wavelength filtered by the infrared filter, a magnetron for heating the to-be-cooked object, a driving motor for rotating the turntable, a thermopile sensor for detecting an infrared signal generated from the to-be-cooked object, a signal processor for processing the signal detected from the infrared sensor, and a controller for controlling the oscillation mode of the magnetron.

Abstract: A control system for a microwave oven having a magnetron unit, a microwave oven using such a control system and methods of making the same are provided, the system being adapted to interconnect a power source to a transformer unit of the magnetron unit to operate the same, the system comprising a unit for determining the actual voltage level of said power source to be utilized at that time and being adapted to interconnect the power source to a particular tap of the transformer unit if the determined power level is above a certain value and to interconnect the power source to another tap of the transformer unit if the determined power level is below the certain value.

Abstract: A microwave sterilization system including a microwave oven having a microwave source that produces microwave radiation. The oven encloses a first chamber and a second chamber. Each chamber has a pouch containing an object and is positioned therein so as to be exposed to the microwave radiation, wherein each pouch has an interior which contains the object corresponding to that pouch. The system further includes a sensor system for detecting the temperatures of said both interiors and produces signals representative of those temperatures. Those signals are sent to the microwave source so as to control the emission of microwave radiation from the microwave source.

Abstract: A microwave heating apparatus is disclosed. The microwave heating apparatus includes: a rectifying section for rectifying an AC current; an inverting section for being turned on/off by the driving signals of a driving section to generate high frequency voltages corresponding to the output signals of the rectifying section; a microwave generating section for receiving the output signals of the inverting section to generate microwaves; a synchronization detecting section for detecting synchronizing signals from the output signals of the inverting section; and a flip flop for being set and reset by the output signals of the synchronization detecting section to control the driving section.

Abstract: A process for extracting extractable material from a base material in which it is present, while protecting against explosion of any solvent vapor in air includes heating by microwave radiation in a closed pressure-resistant and heat-resistant container, such base material, extractable material and organic extraction solvent, passing air near or into contact with the extraction container so that it will carry away from the container any escaping solvent vapor, and passing said air with the solvent vapor, if present, into contact with solvent detector which turns off a source of microwave radiation when the solvent vapor is present. Preferably the invented process will include passing the air, with any solvent vapor which may be present in it, to a flow detector, which will turn off the source of microwave radiation if flow ceases.

Abstract: A power supply for a magnetron varies a power output level and prevents moding of the magnetron. To provide a variable power output, a microprocessor senses an anode current and voltage of the magnetron. Based on the sensed signals, the microprocessor adjusts the conduction angle of a thyristor to obtain the desired power level. The microprocessor also monitors the anode voltage for detecting moding of the magnetron. If moding is detected, the microprocessor adjusts the conduction angle of another thyristor to change the current supplied to the filament. By changing the filament current, the microprocessor effectively prevents the moding of the magnetron.

Abstract: A device for detecting the malfunctioning of a magnetron which operates at start-up with a high power setting P.sub.0, and which is connected to the terminals (21, 22) of the secondary winding (19) of a high-voltage transformer (8). This device includes a device for measuring (28) the peak voltage value sampled in the supply circuit, a device for storing (29) the voltage value measured at successive instants, a device for comparing (30) two successive voltage values giving, in the event of a difference in value, an excess signal (a-b), and a device for detecting (31) the excess signal suitable for sending a malfunction signal to a counting device in order to determine the frequency of the malfunction.

Abstract: A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a furnace cavity (34) for testing or other selected applications. The variable frequency heating apparatus (10) is used in the method of the present invention to monitor the resonant processing frequency within the furnace cavity (34) depending upon the material, including the state thereof, from which the workpiece (36) is fabricated. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a microwave voltage-controlled oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34).

Abstract: A control apparatus and method for a microwave oven capable of fixing an optimum thawing time, coping with unexpected voltage variation of an input AC source. According to the aforesaid apparatus and method, a weight factor corresponding to an input source voltage variation is found, a thawing time proportional to weight of a food item to be thawed is determined, and as a result a final optimum thawing time is determined by multiplying the weight factor and the thawing time together.

Abstract: A microwave output stabilizing apparatus for a microwave oven comprises a rectifier circuit for rectifying power from an AC power supply into a constant DC voltage; an invertor circuit for generating a high frequency power supply by controlling the DC voltage at an intermittent output state; a high voltage transformer for stepping up the high frequency power supply; and magnetron drive circuit for rectifying the high frequency power supply and oscillating a magnetron. Also, an inverter control circuit detects the current flowing into the primary winding of the high voltage transformer, converts the detected current into a corresponding voltage, the corresponding voltage with a reference voltage, and controls the inverter circuit according to the results of the comparison.

Abstract: An explosion proof microwave heated solvent extraction apparatus or system for extracting organic materials includes a pressure resistant microwave transmissive extraction container, which is preferably of reinforced polyetherimide lined with fluoropolymer, in a microwave radiation heated chamber, with a device for controlling a microwave radiation generator, such as a magnetron, in response to the presence of any solvent vapor in a collection container for rupture diaphragm discharged material from an extraction container or in exhaust gas from the chamber. The presence of the solvent in the collection container or exhaust gas is preferably detected by a semiconductor gas sensor which decreases its electrical resistance in the presence of solvent vapors, thereby increasing its voltage and thus controlling operation of the magnetron, turning it off when solvent vapor (and a potentially explosive gas mixture) is present.

Abstract: The invention relates to a microwave oven which neither generates hot spots nor destroys a magnetron by shutting microwaves when there is no load to be heated. This microwave oven is constructed so that the impedances are matched when there is a load, and the impedances are unmatched when there is no load, by shifting the location of the opening of the cooking chamber from the center of the wave guide. When there is no load, as most of the microwaves are converted to standing waves and the pressing waves do not reach the cooking chamber, then it becomes possible to prevent dangers such as the abnormal irradiation of any part, the destruction of the chamber case owing to the occurrence of the heat spot, and the abnormal heat generation due to the leakage of the short waves.

Abstract: A microwave oven includes a heating chamber in which food to be cooked is contained, a magnetron for range-heating the food contained in the heating chamber, a temperature sensor for sensing the temperature of an atmosphere containing hot air emanating from the food being range-heated in the heating chamber, and a controller for controlling an operation of the magnetron based on fluctuations of the temperatures sensed by the temperature sensor.

Abstract: A method for controlling a power relay for actuating a magnetron of a microwave oven in which contacts thereof are closed at various points of time or phase of an AC sinusoidal waveform input thereto with an equal probability, thereby preventing a transfer of the contacts of the power relay. According to the present invention, a count number of a relay counter is incremented periodically upon application of power, until a start key signal is inputted. The count number of the relay counter is then incremented by 1 whenever the start key signal is inputted and the power relay is toggled from its off state to its on state. An interrupt number is incremented periodically as the count number of the relay counter whenever an internal or external interrupt routine is performed. When the count number of the relay counter and the interrupt number are the same, the contacts of the power relay are closed at a phase or a point of time corresponding to the same number, so as to actuate the magnetron.

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: A cooking appliance has a cooking compartment accessed by a door. After cooking is finished, a sensor detects the temperature within the cooking compartment. Then a cooling fan cools components in the cooking appliance for a period of time dependent on the detected temperature. A control circuit changes the period for cooling in accordance with the time that the door is open while the fan is on.

Abstract: A DC power source constituted by a power generator (20), a dynamo (22) and a rectification means (23), an inverter power source (24) which boosts an output of the DC power source so as to drive a magnetron (28) and an inverter controller for controlling the inverter power source (24) by an output of a generated electric power output detecting means (31) for detecting the output of the DC power source are provided, whereby a required dielectric heating function can be stably achieved by controlling an operational state of the inverter power source (24) by the output of the DC power source.

Abstract: A microwave oven having a pulsed magnetron comprises a timing circuit which determines a cooking time and the pulse duration when the magnetron is pulsed. By means of a time and power setting device, the cooking time and the pulse duration are adapted to a food introduced into the oven chamber. At least one operation parameter affecting the magnetron output is measured and compared with the nominal value of the parameter. In the event of a difference between the measured and the nominal parameter value, the cooking time and/or the pulse duration is/are corrected in relation to the set values in order to eliminate the effect of this difference on the total quantity of energy supplied during cooking.

Abstract: A microwave oven having microwave source and a power unit associated therewith which is supplied with mains voltage via a relay. A microprocessor device comprised in the oven is used for controlling switch-on and switch-off of the relay, eliminating thereby the influence by varying switch-on/switch-off times of the one and same relay and between different relays, and allowing for a connection and respectively disconnection of the mains voltage at a desirable phase thereof.