Side Feeder Main Pwb - Olivetti PF-650(B) Service Manual

2-3 Operation of the PWBs
2-3-1

Side feeder main PWB

EH SDI
EH SDO
EH CLK
EF SEL
SF READY
Machine
24 V DC
SFSETSW
UCOSW
5 V DC
SFFSW
ULPSW
RCOSW
UDSW
RDSW
PRDSW
LLPSW
The main component of the side feeder main PWB (SFMPWB) is the CPU U1. It controls the overall operation of the side
feeder by receiving detection signals from switches as inputs and outputting drive signals to motors and clutches.
Communication of control signals with the machine is performed by 3-line type serial communication method.
With the control signal received from the CPU U1, the SFLM driver circuit U6 drives the side feeder lift motor (SFLM). A
safety circuit consisting of the side feeder set switch (SFSETSW), upper cover safety switch (UCSSW) and right cover
safety switch (RCSSW) ensures the security by cutting 24 V DC supply for the SFLM driver circuit U6 and drive output for
the side feeder lift motor (SFLM) when the side feeder is detached from the machine or when the upper or right cover is
opened.
The reset IC U2 monitors the 5 V DC power supply. When the power is turned on and when the supply voltage becomes
low, the reset IC U2 outputs a RESET signal to the CPU U1 to reset the system for the prevention of malfunctions.
Y110900-9
SFMPCB
Serial communication
CPU
(U1)
24 V DC
24 V DC
24 V DC
R
24 V DC
5 V DC
S
5 V DC
5 V DC
S
Reset IC
(U2)
Figure 2-3-1 Side feeder main PWB block diagram
SDA
EEPROM
SCL
(U4)
24 V DC
R
24 V DC 5 V DC
S
SFLM
driver
circuit
(U6)
Service Manual
SPFM
IFM
SFDH
SFCCL
SFPFCL
ULSSW
UCSSW
LLSSW
RCSSW
3MV
SFM
SFLM
2-3-1