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UNC/WN5/FN5/DN5
OF5750/5950 Series January 2001
A3 - 49
4.3
FN5 circuit diagram
1
Lightning arresters (AR1, 2)
The nominal operating voltage is 500 V.
When connecting the ground of the arrestor to the chassis, tighten ARG on the PCB with
a screw. At this time, the PCB is grounded through the power cable.
The TB1 arrestor ground terminal can also be used to connect to the earth directly.
3
Diode bridge (DB1)
This circuit rectifies the loop current so that the DC circuit characteristics are not affected
by a polarity change over the line.
4
DC circuits (Q3, R540, R541, C13, R9, R209)
These circuits provide DC characteristics according to the line requirements.
5
Impedance matching network (R523, R536, C503, R623, R636, C603)
This circuit matches the impedance between the line and equipment to reduce reflection
of transmitted signals.
It provides impedance (return loss) characteristics to meet the line requirement using the
S5-1 and 5-2.
6
Receiving sensitivity (R537, R539, R637, R639)
The receiving sensitivity at line hunting is determined by R539 or R639 and the MF tone
receiving sensitivity at parallel pickup is determined by R537 or R639.
The receiving sensitivity set using DIP switch S5-3 to S5-6.
7
CML (RL1)
This circuit selectively switches the line between the telephone or facsimile.
8
SR (RL2)
This circuit connects the line with the telephone. During facsimile transmission, it discon-
nects the telephone.
9
DP (IC5)
This circuit generates pulse dial signals.
0
MUTE (IC7)
During pulse dialing, this circuit closes to reduce the DC loop resistance.
A
PP (RL6)
When it detects MF or CNG tones without seizuring a line, it disconnects NT (5) to
increase the input impedance and also sets the receiving sensitivity.
B
MUTE (RL3)
During pulse dialing, this circuit opens to prevent pulse distortion caused by capacitor
C11. When it detects MF or CNG tones without seizuring a line, it opens to increase the
impedance.
C
Pickup RC (R590, C31)
These circuits insert a high-impedance resistor and capacitor serially to prevent the line
impedance from dropping by the line transformer T1.
D
Ring detectors (IC1)
These circuits detect a ring signal arriving to the line. If the input ring signal exceeds a
specific voltage, the circuits output a signal of RI having the same frequency as the
incoming RI.
Summary of Contents for OKIFAX 5950
Page 9: ...CHAPTER 1 GENERAL INFORMATION ...
Page 101: ...OF5750 5950 Series January 2001 1 92 1 6 21 NIC Information ...
Page 107: ...CHAPTER 2 INSTALLATION PROCEDURE ...
Page 264: ...CHAPTER 3 BRIEF TECHNICAL DESCRIPTION ...
Page 272: ...CHAPTER 4 MECHANICAL DISASSEMBLY AND REASSEMBLY ...
Page 277: ...OF5750 5950 Series January 2001 4 5 Appearance of the OKIFAX 5750 5950 ...
Page 302: ...CHAPTER 5 ADJUSTMENTS ...
Page 306: ...CHAPTER 6 CLEANING AND MAINTENANCE ...
Page 341: ...CHAPTER 7 TROUBLESHOOTING AND REPAIR FOR OKIFAX 5750 5950 ...
Page 400: ...Appendix A PC Board Descriptions and Operation ...
Page 491: ...Appendix B DescriptionsofPrintOperation ...
Page 513: ...Appendix C Not used at this time ...
Page 516: ...OF5750 5950 Series January 2001 D 1 Section 1 CABINET ASSEMBLY 27 28 29 ...
Page 518: ...OF5750 5950 Series January 2001 D 3 Section 2 CONTROL PANEL ASSEMBLY 11 ...
Page 520: ...OF5750 5950 Series January 2001 D 5 Section 3 PRINTER ASSEMBLY 53 54 31 10 55 52 34 56 ...
Page 523: ...OF5750 5950 Series January 2001 D 8 Section 4 BASE ASSEMBLY ...
Page 525: ...OF5750 5950 Series January 2001 D 10 Section 5 FRAME ASSEMBLY SCANNER L 31 30 33 32 ...
Page 527: ...OF5750 5950 Series January 2001 D 12 Section 6 FRAME ASSEMBLY SCANNER U ...
Page 529: ...OF5750 5950 Series January 2001 D 14 Section 7 CABLES OPTION BOARDS ...
Page 530: ...OF5750 5950 Series January 2001 D 15 28 29 Section 7 CABLES OPTION BOARDS ...
Page 532: ...Appendix E Not used at this time ...