The so-called Fuser thermistor is also a resistor. Using temperature to adjust the size of the resistance can determine whether the fixing temperature is normal.

The application of Fuser thermistor is multi-layered, which means that it exists in many parts. The central thermistor is the main thermistor, which detects the temperature of the central part of the fuser roller, and controls the on and off of the fuser lamp; the Fuser thermistor on the side is a secondary thermistor, because the paper does not pass through the heat roller and the paper is not absorbed With heat, both sides of the fuser roller may overheat. The sub-temperature thermistor can detect abnormal heat generation in this area caused by the overheating of the fixing roller. Therefore, the sub thermistor is not used for temperature control of the fixing roller, only monitoring the temperature of the fixing roller is abnormal.
The main function of Fuser thermistor is to adjust the fixing temperature. The Fuser thermistor is tightly attached to the upper fixing roller or ceramic heater. When its temperature changes, its resistance changes. The logic circuit controls the switch of the heating lamp to realize the adjustment and constant temperature of the fixing temperature. The thermistor used in laser printers basically has a negative temperature coefficient. That is, the higher the external temperature, the lower the resistance of the Fuser thermistor. When the lamp tube starts to heat up. The temperature of the heating roller gradually increases, and the resistance of the thermistor decreases. When the surface temperature of the heater reaches the rated temperature, the resistance of the thermistor also reaches the lowest value, and then the heater is controlled to stop heating through the logic control circuit. This is repeated to control the surface temperature of the heater to keep within the designed temperature range.
The role of Fuser thermistor should not be underestimated. Without the existence of this electronic component, the performance of the fuser cannot be guaranteed. And relatively speaking, the quality of electronic components determines the effect and service life of the fuser. Therefore, attention to quality selection is a crucial detail.