Drum Temperature Detection Circuit; General Description; Construction - Toshiba e-STUDIO200L Service Manual

11.4 Drum Temperature Detection Circuit

11.4.1

General description

If the temperature of the drum and its surrounding area becomes too high, the property of the toner
which is recovered by the drum cleaner easily changes. To prevent this, the drum thermistor detects the
surface temperature of the drum. Based on the result, it controls the exhaust fan and internal cooling
fan-1 to cool down the inside of the equipment.
11.4.2

Construction

The configuration of the drum surface temperature detection circuit is shown below. The input voltage
from the drum thermistor is converted by an A/D converter in the Engine-CPU on the LGC board. The
drum thermistor is a device whose resistance decreases as the temperature rises. Namely, the input
voltage to the Engine-CPU becomes smaller along with the rise of the temperature.
Drum
thermistor
e-STUDIO200L/202L/203L/230/232/233/280/282/283
DRUM RELATED SECTION
LGC board
+5V
DRTH
GND GND
Fig. 11-4
11 - 6
Engine-CPU
DRTHP-1
PC2/AN2
IC22
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