Olivetti d-Copia 300, Service Manual

Page: 326 / 351

2FD/2FF/2FG
2-3-22
2-3-4 Scanner drive PCB
SM
SM A
SM _A
SM B
SM _B
SM Vref
SM M1
SM M2
SM M3
SM M4
SM M5
SM CLK
SM CWB
SM RET
DT1
DT2
SM ENABLE
EL ON REM EL
EL
INPCB
ODSW
ODSW
SHPSW
SHPSW
SDPCB
MPCB
Stepping
motor
driver
IC1
Figure 2-3-8 Scanner drive PCB block diagram
The scanner drive PCB (SDPCB) consists of a stepping motor driver IC (IC1) as the center, digital transistors DT1 and DT2,
etc.
Drive of the scanner motor (SM) is controlled by the current setting voltage (SM Vref) that is output from the main PCB
(MPCB), the mode signals (SM M1 to M5, SM CWB), the phase switchover clock signal (SM CLK), and the drive/stop signal
(SM ENABLE).
Also the main PCB (MPCB) outputs a control signal (EL) through a digital transistor (DT2) to the inverter PCB (INPCB) to
turn on or off the exposure lamp (EL).
Also the scanner drive PCB (SDPCB) acts as an interchange circuit of signals for the original detection switch (ODSW) and
the scanner home position switch (SHPSW).