Tokyo Shibaura Denki Kabushiki Kaisha

Tokyo Shibaura Electric Co., Ltd.

Hidetoshi Semi

Masayuki Sasaki

Yoshio Oida

A zero-crossing signal is generated in response to the zero-crossing of the current of an AC power source of a magnetron oscillator, and in response to the zero-crossing signal a triac connected between the magnetron oscillator and the AC power source is turned on to generate a microwave. The triac is turned off when the voltage of the AC power source becomes lower than a holding voltage of the triac.

Power control circuit for a magnetron oscillator

A system for entering a temperature setting into a memory store and for displaying it, wherein the temperature setting includes a temperature level portion and a temperature scale portion. The temperature level portion corresponds to the temperature at which a microwave oven, for example, is to be set and the temperature scale portion indicates whether the temperature level portion is calibrated in degrees Fahrenheit or degrees Celsius. The temperature level is inputted through a decimal keyboard and a key signal encoder. Gating circuits transfer the temperature level from the key signal encoder and the temperature scale from a temperature unit code generator to a memory under control of a preprogrammed instruction data generator. A display circuit and display unit are coupled to the memory for displaying the temperature setting. A temperature level is supplied to a temperature setting register through another gating circuit to provide the temperature level to a temperature control circuit external to the temperature entering and displaying system.

System for entering temperature control data and displaying it with the

An output power control system includes an output power control circuit for producing first and second control signals to control a switch and a semiconductor control element which are inserted between a power source and an oscillating magnetron tube. The output power control circuit includes a main control section and an output control section. The main control section receives a door signal representing the open or closed state of an oven door and an initiating pulse for initiating the operation of the output power control circuit. The same section periodically detects the door signal to produce first and second set signals when the door is closed at the detection, and to produce first and second reset signals when the door is open. The output control section includes a first means and a second means. The first means produces the first and second signals to cause the magnetron tube to oscillate when receiving the first and second set signals while it stops the production of the first and second signals thereby to stop the oscillation of the magnetron tube when receiving the first and second reset signals. The second means immediately stops the oscillation of the magnetron tube by stopping the production of the first and second control signals as the door is opened during the oscillation period of the magnetron tube.

Output power control system for microwave ovens

Disclosed is a power level setting/display circuit for a microwave oven which comprises a logical gate circuit for feeding a maximum power level signal to a setting register by means of a function key for power level setting, a logical gate circuit for supplying the fed maximum power level signal to a display register, a logical gate circuit for storing a power level command signal in a temporary storage register, a logical gate circuit for clearing the contents of the display register simultaneously with such storage of the power level command signal, a logical gate circuit forming a series closed loop by means of the display register and temporary storage register, whereby the power level command signal stored in the temporary storage register will be shifted to the bottom digit of the display register, and a logical gate circuit for supplying the power level command signal stored in the display register to the setting register.

Growing community of inventors

Kamakura, Japan

Hidetoshi Semi