Tektronix Phaser 340 Service Manual page 96

5
Theory of Operation
5-4 Phaser 340 Color Printer
The drum is driven by a closed-loop servo motor which, through a double
reduction belt drive, rotates the drum at 190 rpm for imaging and a constant low
speed for image transfer to paper.
Home sensor
Encoder
disk
Home
flag
Encoder
Drum heater
Servo motor
Warning: Closed-loop
servo drive
Figure 5-3 The drum/transfix assembly
Warning
Keep your fingers away from the drum drive system; it uses a
closed-loop drive system. A closed-loop servo drive system is
inherently dangerous. Since the motor speeds up if it senses the
drum drive system slowing down, fingers caught in the drum belts
and gears can be severely injured.
Temperature
sensor (~49°C)
Drum
Transfer roller
Fan
Belt drive
9100-13