103
OP-P1/MF1 Training
Slide 103
Temperature Control (1)
The thermistors (center and right end) [3] touch the surface of the
hot roller [1].
They measure the temperature of the hot roller surface every 50
ms.
The center thermistor detects temperature where paper passes
between the rollers, while the right end thermistor detects
temperature where paper does not pass between the rollers
One thermostat [4] is mounted above (but does not touch) the
surface of the hot roller.
It constantly monitors temperature inside the fusing unit.
The thermostat switches the machine off when the temperature
rises above 185
°
C (365
°
F).
The thermistor is a contact NTC type. This means that it has a negative
temperature coefficient (NTC) so its resistance decreases as the temperature
increases.
