Board Descriptions
A - 26
OKIOFFICE 44 Serv. Man., P/N 59276801
A3.1.4
R44 Circuit Diagram
1.
Block diagram
The audio monitor circuit consists of IC11 (analog switch IC) and IC5 (amplifier) generates the
following audio monitor.
•
Line monitoring
•
Buzzer signals
Figure A3.1.4 shows the block diagram of audio monitor circuit.
2.
Function
1)
Line monitoring
Send and receive signals are input from the transformer on the NCU board to this circuit as
a
R signal and the signal power is input to the IC11. The IC11 adjusts the monitor
volume by MONC0, MONC1 and MONC2 signal under the control of IOGA3. Output
(high and low) from IC11 passes through the amplifier and is fed to the speaker as a SP
signal.
* MONC0/MONC1/MONC2 signal: Volume control signal.
Note: In case of transmission mode, the monitor will be available during dialing, but the
monitor will be switched off automatically after the elapse of specified time (about 5
sec).
2)
Buzzer control
Alarm and other signals are input from CPU to this circuit as BZ signals. The various
buzzer signals are sounded under the control of CPU.
Figure A3.1.4 Block Diagram of Audio Monitor Circuit
IC11
IC2
IOGA3
CPU
RM
Analog
switch
IC5
Amplifier
CN9
1
2
Speaker
BZ
MONC1
MONC2
MONC0
0 V
0 VA
+5 V
0 VA
TR1
Summary of Contents for OKIOFFICE 44
Page 2: ...All specifications are subject to change without notice Service Manual OKIOFFICE 44 59276801...
Page 135: ...Disassembly 4 6 OKIOFFICE 44 Service Manual P N 59276801 Whole Unit Picture FX048 CP4 1 Fig 01...
Page 329: ...Illustrated Parts List D 6 OKIOFFICE 44 Service Manual P N 59276801 Section 2 Printer Unit...
Page 331: ...Illustrated Parts List D 8 OKIOFFICE 44 Service Manual P N 59276801 Section 3 Operator Panel...
Page 351: ...Illustrated Parts List D 28 OKIOFFICE 44 Service Manual P N 59276801 Section 12 Cables...
Page 357: ...Board Layout E 2 OKIOFFICE 44 Service Manual P N 59276801 MEM eps E 2 MEM PCB...
Page 358: ...Board Layout E 3 OKIOFFICE 44 Service Manual P N 59276801 TEL U eps E 3 TEL U PCB...
Page 359: ...Board Layout E 4 OKIOFFICE 44 Service Manual P N 59276801 Hook eps E 4 Hook PCB...
Page 388: ...OKIOFFICE 44 Service Manual Part Number 59276801 Printed in the USA...