How big is the thermistor?Automatic machine mirror

　　There are many types of thermistors. As temperature measurement, there are generally glass seal type, epoxy resin type, small head diameter enameled wire type, etc. As a temperature measurement component of an induction cooker, a glass seal type plus other accessories are generally used to form a thermal sensor. The resistance component, the thermistor with negative temperature coefficient, that is, the NTC thermistor, has a resistance value of about 100K at room temperature, and there are also 10K, 50K and other specifications, but 100K is used more, and the error is mostly ±1% or ±2 %, the resistance of the NTC thermistor decreases as the temperature increases. The following picture is an accessory of an induction cooker thermistor temperature probe. In actual use, the thermistor is closely attached to the ceramic plate, and thermal grease is applied to the contact to improve the control sensitivity.

　　Induction cooker temperature measurement generally adopts A/D port detection. Now many chips have A/D detection function. As shown in the figure below, NTC thermistor is connected in series with another resistor, and the AD value is read by using the principle of resistance division. The value obtained from the partial pressure is compared to judge the current temperature. The thermistor of the induction cooker not only plays a role in temperature measurement, but also plays a role in ensuring safety. When the temperature reaches a certain value, the circuit will automatically disconnect the output. When the resistance is abnormal (such as short circuit or open circuit), the corresponding error code will be displayed, which is very convenient to find out the reason during maintenance and inspection.

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