HP laserjet 1018 Manuale Di Servizio

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Engine control system (engine control unit and power assembly)
The engine control system coordinates all print engine activities. The engine control system includes
both the engine control unit (ECU) PCA and the engine-power-assembly PCA.
NOTE
In other HP LaserJet products, the ECU and power functions are combined onto one
PCA known as the controller PCA or the DC controller PCA. In the HP LaserJet 1018 printer,
the control functions are primarily relegated to the ECU PCA, and the power functions are
relegated to the engine-power-assembly PCA.
The ECU controls the following systems and functions:
Printer-engine control
Paper-motion monitoring and control (printing)
Motor
Printer laser/scanner unit
The engine-power assembly provides the following features in the power system:
AC power distribution
DC power distribution
Overcurrent/overvoltage protection
High-voltage power distribution
Printer-engine-control system
Paper motion monitoring and control
The ECU controls paper motion in the printer by continuously monitoring the two paper sensors and
coordinating the timing with the other print processes.
For a detailed explanation of paper movement and the interaction of the sensors and pickup solenoid
with the paper-movement process, see 
.
Motor
The ECU controls the motor. The motor drives all of the paper movement in the printer.
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Chapter 4   Operational overview
ENWW