A method for initializing and controlling the absolute humidity sensor of a microwave oven

Abstract

The invention discloses an initial control method for a microwave oven absolute humidity sensor. The method involves a Wheatstone bridge circuit arranged on the humidity sensor and five shunt resistors are arranged inside the Wheatstone bridge circuit. The method includes the steps that in view of the characteristics of the absolute humidity sensor and change of the humidity sensor value, an optimal standard value is set; in order to complete initialization at the highest speed, the current voltage value of the humidity sensor is compared with the standard value, and initialization is conducted again; in the course of initialization, the current voltage value of the humidity sensor is compared with a previous voltage value of the humidity sensor, and then whether the current voltage valueof the humidity sensor is in an increasing state or in a progressive degreasing state is judged; the shunt resistors are adjusted in the increasing state, the voltage value of the humidity sensor is turned down, the shunt resistors are adjusted in the decreasing state, the voltage value of the humidity sensor is turned up, and finally the optimal initial value is found out; and when initializationfails or cooking errors happen along with change of the ambient environment and the like, false alarms are raised by an alarming apparatus so as to remind users to conduct initialization again.

Description

technical field [0001] The invention relates to an initialization control method of an absolute humidity sensor of a microwave oven. Background technique [0002] Generally speaking, in a microwave oven using an absolute humidity sensor for the humidity sensor cooking function, at the starting point of absolute humidity induction cooking, or when the high-frequency heating device is not activated at all, in order to make the voltage at the connection point of the Wheatstone bridge circuit To be consistent, the resistor has been set, such as figure 1 As shown, when cooking with the humidity sensor in this state, +5V voltage will be applied to the absolute humidity sensor. [0003] At this time, MCU (Microcontroller Unit, microcontroller, which is used for calculation / input and output, integrated circuit with storage function) will according to the built-in circuit structure, such as figure 2 As shown in , connect the parallel resistors connected to the output terminals to ...

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Problems solved by technology

[0004] However, the initialization method of the microwave oven has always connected about 3 parallel resistors. When the humidity sensor is cooking, with the increase of the parallel resistance, the initialization can be carried out more carefully, but the initialization time is too long, and electromagnetic wave noise (external generation) Abnormal signals, such as high-frequency noise, high voltage or short-term high voltage and current, etc.), due to initialization failure, or wrong initial standard value to sense humidity, cooking performance errors will occur

[0005] At the same time, due to the error of the humidity sensor and the failure of the humidity sensor, due to the wrong initial standard value, the wrong alarm (buzzer sound, warning display) to stop the cooking work, and the method of cooking again is currently not available.

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