High frequency heating apparatus with wireless temperature probe

A high frequency heating apparatus with a wireless temperature probe, comprising:

• a. a heating chamber for containing an object to be heated;
• b. high frequency power supply means for supplying high frequency power into said heating chamber thereby to heat said object housed in said heating chamber;
• c. a power supply circuit section for receiving the high frequency power suppled into said heating chamber from said high frequency power supply means at an appropriate position in said heating chamber and rectifying said high frequency power thereby to provide a DC power supply, a temperature-measuring section including a thermistor for sensing the temperature of the inside of said object to be heated, an oscillator circuit section for oscillating at a frequency determined by a time-constant capacitor and the resistance value of said thermistor of said temperature-measuring section, an ultrasonic wave transmitter section driven by said oscillator circuit section for transmitting an ultrasonic wave, and casing means for protecting said power supply circuit section, said temperature measuring section, said oscillator circuit section and said ultrasonic wave transmitter section from the strong electric field of high frequency in said heating chamber, said power supply circuit including a rectifying diode and strip lines, said strip lines including a main line for conducting the high frequency in said high frequency heating chamber, shorting lines for forming an electric wave shorting plane at the position of a rectifying diode, and a DC feedback line for passing the rectified DC power, the main line being about .lambda.g/2 long, the shorting lines and the DC feedback line being .lambda.g/4 long where .lambda.g is the wavelength of the high frequency on said strip lines, an end of said DC feedback line being shorted to the ground side of the strip line base plate by a conductor by way of a through hole formed in said strip line base plate, said ground side being provided on the back of said strip line base plate and making up part of a metal plate for shielding said power supply circuit;
• d. an ultrasonic wave receiving section mounted on the wall of said heating chamber and protected from the strong electric field of high frequency in said heating chamber for receiving the ultrasonic wave transmitted from said ultrasonic wave transmitter section contained in said casing means;
• e. signal processing means for deciding the temperature of said object on the basis of the ultrasonic wave signal received at said ultrasonic wave receiving section;
• and
• f. control means for controlling the operation of said high frequency power supply means on the basis of the signal from said signal processing means.