Microwave oven adopting non-contact type electromagnetic induction temperature measurement and temperature measuring method

Abstract

The invention discloses a microwave oven adopting non-contact type electromagnetic induction temperature measurement and a temperature measuring method. The microwave oven comprises a casing, a heating chamber arranged inside the casing, a magnetron for heating the heating chamber, a turntable positioned in the heating chamber, a motor for driving the turntable to rotate and a control circuit, wherein a utensil which is used for accommodating foods and allows microwaves to penetrate through for heating is arranged on the turntable; a temperature measuring element is arranged below the turntable and comprises a temperature measuring inductive coil and a magnet exciting coil; a magnetic temperature sensing element which corresponds to the magnet exciting coil and allows the magnetic induction density to change along with the change of the temperature is arranged at the bottom of the utensil; the magnet exciting coil is used for exciting the temperature measuring inductive coil; and a temperature sensing magnetic field is formed between the temperature measuring inductive coil and the magnet exciting coil and is used for converting a magnetic signal generated by the magnetic temperature sensing element at different temperatures into an electrical signal and outputting the electrical signal so as to detect the temperature of the utensil. According to the microwave oven and the temperature measuring method disclosed by the invention, automatic, flexible and accurate control of temperatures of multiple points of the microwave oven in the cooking process can be realized.

Description

technical field [0001] The invention relates to a microwave oven and a temperature measuring method of the microwave oven, in particular to a microwave oven and a temperature measuring method using non-contact electromagnetic induction temperature measurement using the magnetic permeability temperature characteristics of iron or ferrimagnets. Background technique [0002] A microwave oven is a modern cooking stove that uses microwaves to heat food. Microwave is a kind of electromagnetic wave. The energy of this electromagnetic wave is not only much greater than that of ordinary radio waves, it will reflect as soon as it touches metal, and there is no way for metal to absorb or conduct it; microwave can pass through insulating materials such as glass, ceramics, and plastics. Materials, but will not consume energy; and food containing water, not only can not pass through the microwave, but its energy will be absorbed. In the prior art, the temperature control of the food in t...

AI Technical Summary

Problems solved by technology

Its disadvantage is: due to the existence of strong electromagnetic field when the microwave oven is working, when the microwave oven is working, its strong magnetic field will interfere with the magnetic sensor's detection of the magnetic signal sent by the temperature-sensitive magnetic steel at the set temperature point. Therefore, let the magnetic sensor detect when the magnetron is powered off. After the detection work is completed, the magnetron is powered on again. This process continues until the magnetic sensor detects that the food is at a certain set temperature. until the signal

Therefore, this technical solution has the following defects: (1) in order to ensure the normal detection of the magnetic sensor, the power supply of the magnetron should be often disconnected, which is not conducive to the normal heating work of the microwave oven; The power supply time of the electric tube will vary according to the amount of food to be heated. Therefore, it is difficult to set a more suitable time point for all situations. If the power-off time point is set early, the number of power-off times will increase and If the detection time is too long, it will affect the heating efficiency; (3) The frequent switching action of the high-power magnetron or power module of the microwave oven will have an impact on the control system, which will affect the service life of the control system; (4) It is difficult to control multiple temperatures Point detection: Since different cooking procedures require the control of different temperature points, that is, not all cooking procedures require reaching the Curie point to work, and this detection method can only detect the Curie point temperature of the temperature-sensing magnetic steel, and the It cannot detect multi-point temperature, so it cannot flexibly and accurately control the multi-point temperature required in the microwave cooking process, and the temperature detection is still limited

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