Abstract: A microwave oven includes a heating chamber, a plurality of cooking utensils detachably disposed in the heating chamber selectively in accordance with the cooking contents, a plurality of heat sources heating food placed on or contained in the cooking utensil and including a magnetron, an oven heater and a grill heater, optical sensors determining the cooking utensil disposed in the heating chamber, and a microcomputer. The cooking utensils include a glass dish, thawing gridiron, pot, upper and lower top plates, one-legged top plate, and gridiron. A microwave cooking mode is selected when the determination of the optical sensors indicates that neither upper nor lower top plate is present in the heating chamber. A heater cooking mode is selected when either upper or top plate is present. When the heater cooking mode is selected on the basis of presence of the upper top plate, either an oven mode or a grill mode is selected depending upon presence or absence of the gridiron.

Abstract: In a magnetron drive apparatus a high frequency voltage converted and outputted by a frequency converter is inputted to a primary winding of a transformer and a high voltage power outputted from a secondary winding of the transformer is rectified and supplied to an anode of the magnetron and a power outputted from a heater winding of the transformer is supplied to a heater of the magnetron. The magnetron drive apparatus comprises a magnetic flux leakage device disposed in a magnetic path formed by the primary and secondary windings of the transformer and increasing a leakage magnetic flux in the magnetic path; and a device for winding the secondary winding and the heater winding therearound in a position opposite the primary winding with the magnetic flux leakage device arranged therebetween.

Abstract: An electric apparatus involves a temperature sensor and a controlled circuit connected to an A.C. source to be sequentially controlled in accordance with the output from the temperature sensor. The control device comprises an auxiliary power source, a first control circuit for controlling the controlled circuit, and a second control circuit for supplying first control signals to the first control circuit, each being connected between control lines. The second control circuit involves an oscillator for producing clock pulses, a generator for generating reset pulses synchronized with the frequency of the A.C. source, a counter which counts the clock pulses and is reset upon receipt of the reset pulses, a control signal generator which processes an output signal from the temperature sensor to produce the first control signals, and circuit arrangements which, when a momentary power failure takes place in the A.C.

Abstract: A microwave heating apparatus comprises a solid state oscillating circuit, a pre-amplifier module for amplifying the output of the oscillating circuit, a plurality of amplifier modules for amplifying the output of the pre-amplifier module, a first power supply source for energizing the solid state oscillating circuit and a second power supply source for energizing all of the amplifier modules. Such an apparatus further comprises a delay circuit for activating the first power supply source after the second power supply source has been activated and the amplifier modules have been in a stable state.

Abstract: An electric rice cooker is disclosed which has a cooking pot or kettle for containing rice and water, an electrical cooking heater provided adjacent to the outside surface of the kettle for heating the kettle and its contents, a thermal insulating frame structure including a removable lid member, and a kettle temperature measuring device including a thermally sensitive resistor. A connection failure of the thermally sensitive resistor is detected after a specified time interval has lapsed after starting the cooking operation. The detection is carried out in accordance with a decrease in level of the output from the kettle temperature measuring device, thereby stopping the supply of power to the heater and at the same time informing the operator of the connection failure.

Abstract: An electric rice cooker is disclosed which performs auxiliary cooking such as "twice cooking" by changing the operating time of auxiliary cooking in accordance with the actual cooking amount, immediately after the main cooking is completed. The actual temperature of a kettle which contains rice and water and which is detachably mounted in a thermal insulating frame is measured by a thermistor. Upon deenergization of an electric heater after main cooking is completed, the actual kettle temperature decreases. A time interval for the kettle temperature to go from a first temperature at the completion of main cooking to a second temperature is closely related to the actual cooking amount. The auxiliary cooking time interval is determined by a control circuit arranged in a case in accordance with the time interval described above.

Abstract: An electric rice cooker is disclosed which has a cooking pot or kettle for containing rice and water, a removable lid member covering the top of the kettle, an electrical heater provided adjacent to the outside surface of the kettle for heating the kettle and the contents thereof, a thermal insulating frame structure, and a control section which includes a kettle temperature detector and a control circuit for controlling the heater so as to allow the rice to automatically and properly absorb water in accordance with the actual kettle temperature immediately after the cooking operation is started, but before the rice is substantially changed to alpha-starch.

Abstract: An electric rice cooker is disclosed which includes a cooking kettle for containing rice and water, a removable lid member covering the top of the kettle, a heater provided adjacent to the outer bottom surface of the kettle to heat the kettle, and a thermistor for measuring the actual kettle temperature. A cooking amount measuring circuit for detecting the actual amount of kettle contents every time a cooking operation is performed, and a control circuit for controlling the operation of the heater by determining the proper time at which the heater should be turned OFF in accordance with actually measured data obtained during the cooking operation which is being performed, are arranged in a case.

Abstract: An electric rice cooker is disclosed which has a cooking kettle containing rice and water, a thermal insulating frame and an electric heater provided adjacent to the outside surface of the kettle. The electric rice cooker performs auxiliary cooking, such as "twice cooking", for effectively converting beta-starch to alpha-starch after main cooking is completed. The auxiliary cooking operating time is properly determined in accordance with the actual amount to be cooked when every cooking operation is performed. The actual amount to be cooked is detected by a control circuit arranged in a case in accordance with a change in actual kettle temperature measured by a thermistor after a heater is deenergized, that is, in accordance with a peak temperature obtained by "after heat".

Abstract: The operation of an object to be controlled, operation hour data, operation day-of-week data etc. are keyed in from a keyboard randomly and are displayed by a display unit, while at the same time these are stored in an input buffer. Upon depression of a transfer key, the correctness of the key-in items stored in the input buffer is checked by a microprocessor controlled by a program stored in a read only memory. When the item is incorrect, the display of the incorrect item is flashed in the display unit to request an operator to make a key-in again. When all the items are correctly keyed in, those are transferred to the memory portion to execute a given operation.