KR980007852A - No-load judgment device and method of microwave - Google Patents

Abstract

The present invention relates to a non-load determination apparatus and method of a microwave oven, which affects the life of the magnetron when operating the magnetron in the state without a food in a conventional microwave oven, the risk of fire due to overheating of the heating chamber In addition, there is a problem that the turntable can melt when the turntable is a material that can not withstand high temperatures.

Therefore, in the present invention, when the temperature is measured using a thermopile sensor, the expected measurement according to the type of key selected by the user compares the value with the actual measured temperature value, or when the surface temperature of the food is changed and the no-load when the magnetron is operated. It is possible to use a weak but inexpensive turntable by using magnets or turntables to terminate the magnetron operation before the heating chamber is overheated by judging whether there is no load by using different patterns of turntable surface temperature. Even in case of the test, no-load can be judged.

Description

No-load judgment device and method of microwave

As this is a public information case, the full text was not included.

3 is a flowchart illustrating a conventional method for determining a no-load of a microwave oven.

4 is a configuration diagram of a microwave oven for determining the no-load of the present invention.

5 is a temperature change characteristic when the food is located in the center of the turntable in FIG.

6 is a temperature change characteristic diagram when food is eccentric in the center of the turntable in FIG.

Claims (6)

A sensor module for measuring a surface temperature of food and converting the measured temperature into a voltage value and outputting the measured voltage; A microcomputer including an analog / digital converter for converting the output voltage of the sensor module, which is an analog signal, into a digital signal, and including a built-in algorithm to control the heating means; A magnetron for heating the load according to the control output of the microcomputer; A turntable on which a load is placed; And a turntable driving motor for rotating the turntable. 2. The apparatus of claim 1, wherein the sensor module comprises a thermopile sensor and an amplifier. A first step of terminating the operation of the heating means by determining no load if the minimum value of the temperature measured during the initial turntable rotation when the user selects the thawing dish is higher than an arbitrary temperature value TO; A second step of measuring a temperature of a heating chamber when selecting dishes other than thawing in the first step; Calculating a temperature increase rate per unit time (SI) when the temperature (T) measured in the second step is in the range between 50 ° C and 70 ° C and a temperature increase rate per unit time when in the range between 70 ° C and 90 ° C. Step 3; In the third step, if the temperature increase rate SI and S2 are similar values, it is determined as no load to terminate the operation of the heating means, and if it is not a similar value, a fourth step of performing a cooking algorithm is performed. . 4. The method of claim 3, wherein the predetermined temperature TO is 10 DEG C in the first step. The method according to claim 3, wherein if no load is determined in the fourth step, the temperature increase rate (S3) per unit time in the range of 90 ° C to 110 ° C is calculated, and if the temperature increase rates S2 and S3 are similar values, it is determined as no-load and heated. And a fifth step of terminating the operation of the means. 6. The method of claim 5, further comprising a sixth step of determining that there is no load or no fire in the heating chamber when the measurement temperature is higher than 120 ° C. in the fifth step. No load judgment method of microwave oven.