Brother DX-2000, Service Manual

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III-1
CHAPTER III ELECTRICAL SYSTEM
1. COMPOSITION
Regurator
I/F circuit
GND
+24V
+5V
Fan drive circuit
Motor drive circuit
CPU
M50927
I/F PCB
Printer
Main PCB
Figure 3.1
2. MAIN PCB FUNCTION
2.1 I/F Circuit
This interface circuit is used to transmit and receive data with the printer. Since the
Duplex unit responds only to commands from the printer, the Duplex unit transmits its
status upon request from the printer.
2.2 Regulator
The regulator pr5V logic power supply from the +24V supplied by the printer.
2.3 Fan Drive Circuit
This circuit drives the cooling DC fan.
The fan rotation speed is switched between two different levels according to the signal
from the CPU. It operates at high speed when the Duplex unit feeds paper, or it runs at
low speed while the unit is not in operation.
When the DC fan functions properly, it sends a /FLOCK signal to the CPU to confirm that
it is normal.
2.4 Motor Drive Circuit
According to the signal from the CPU, this circuit drives both the reversible motor and the
paper pressure motor.
2.5 Solenoid Actuator
According to the signal from the CPU, this actuator turns the solenoid on or off.
2.6 Sensor Input
Signals to each of the reverse sensor, cassette sensor and open cover sensor are
imported to the CPU port.