Olivetti FAX System M-New Service Manual page 84

2-2-2 NCU PWB
FCPWB
LINE1
Noise
fileter
circuit
LINE2
C038, C039
EARTH
TELOFHKn
TEL SEL
DCCONT
Q47
Q48
Y108810-2
Accounting
pulse
elimination
circuit
C041, C042
C043
Ground start
circuit
DB20, PC20
External telephone
off-hook detection
circuit
U11
DC/DC converter on/off
circuit Q48, Q49
DC/DC converter circuit
Q47
Off-hook detection circuit
photo coupler PC40
Figure 2-2-3 NCU PWB block diagram
PC20
DB20
PC40
Figure 2-2-4NCU PWB silk-screen diagram
Service Manual
Noise
fileter
circuit
Relay
circuit
Q10
TEL_DET1
TEL_DET2
V10
U11
YC1
3KH
Surge
absorption Line
section
(modular
V10, V12
connector)
V11
Tel
(modular
connector)
V11
V12
2-2-5