Oki OKIFAX 5400 Maintenance Manual page 329

TEL-U (option)
CN1
Connected to
HOOK Circuit
CN3
Connected to
UNC Circuit
DB1
~
+
+
~
-
Rectifier
Figure A3.5.1 Block Diagram of TEL-U (option)
Speech Network Circuit
Speech IC (IC1)
VL T12
CL T11
+
R02
R01
CN2
Microphone
Handset
Receiver