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Board Descriptions
A - 54
OKIOFFICE 44 Serv. Man., P/N 59276801
A3.8
TELU Circuit Diagram (Option)
The TEL U Board is used for control of the telephone set when the optional telephone assembly is
installed on the facsimile transceiver,
1.
Block diagram
•
Figure A3.8.1 shows a block diagram of TELU circuit.
2.
General functions of this circuit are as follows:
•
Speech IC
•
Sending Level Adjustment
•
Receiving Level Adjustment
•
Sending Frequency Response Adjustment
•
Side Tone Adjustment
•
DC V-1 Characteristics Adjustment
•
Return Loss Adjustment
•
AGC (automatic gain control)
•
Manual Pad
•
Sending Frequency Response Adjustment
•
Receiving Frequency Response Adjustment
•
Handset Interface
3.
Explanation of TEL circuit diagram
This section describes functional blocks of individual TEL circuit diagram.
3-1
TELU circuit diagram
TELU circuit diagram is formed by Speech IC and interface of UNC, HOOK SW and HANDSET.
1)
Speech IC
The hybrid circuit is formed by Speech IC.
2)
Handset Interface
•
Transmitter signal route
Signal from the microphone of the handset is input to pin 15 and 16 of Speech IC. This
signal is determined by the amplification factor and output to the telephone line via
UNC, Hook switch and DB2 (rectifier).
•
Receive signal route
Receive signal from the telephone line enters Speech IC via UNC, Hook switch and
DB2 and is output to pin 2 & 3 of the speaker of the handset.
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...