AM-900U
5 – 20
1.3.4 CML relay
The CML relay switches over connection to the matching transformer
T1 while the FAX is being used.
1.3.5 Matching transformer
The matching transformer performs electrical insulation from the tele-
phone line and impedance matching for transmitting the FAX signal.
1.3.6 Hybrid circuit
The hybrid circuit performs 2-wire-to-4-wire conversion using the IC of
operational amplifier, transmits the voice transmission signal to the
line, and feeds back the voice signal to the voice reception circuit as
the side tone.
1.3.7 Signal selection
The following signals are used to control the transmission line of FAX
signal. For details, refer to the signal selector matrix table.
[Control signals from output port]
[Signals for status recognition according to input signals]
[Other signals]
1.3.8 CI detection circuit
The CI detection circuit detects the CI signals of 15.3 Hz to 68 Hz. A CI
signal, which is provided to the photo-coupler PC1 through the C1
(0.82 uF), R6 (22K), and ZD3 and R5 (13K) when the ring signal is
inputted from the telephone line.
1.3.9 Power supply and bias circuits
The voltages of +5V and +24VA are supplied from the control PWB
unit.
(Example: Fax signal send)
Signal Name
Description
CML0
Line connecting relay and DP generating relay
H: Line make
L: Line break
SP MUTE
Speaker tone mute control signal
H: Muting (Power down mode)
L: Muting cancel (Normal operation)
VOL A
VOL B
VOL C
(the circuit is
located in the
control PWB.)
Speaker volume control signal
L
H
L
VOL A
L
L
L
VOL B
L
L
H
VOL C
VRSEL1 VRSEL2 matrix
-
High
Low
Buzzer DTMF
High
Middle
Low
High
Middle
Low
RING./
Receiving
Signal Name
Function
CI
Incoming call (CI) detection signal
EXHS
H: The handset or external telephone is in the
on-hook state.
L: The handset or external telephone in the off-
hook state.
Signal Name
Function
TXOUT
Transmission (DTMF) analog signal output
from modem
RXIN
Reception (DTMF, others) analog signal input
into modem
No.
Signal Name (CNLIU)
No.
Signal Name (CNLIU)
1
RXIN
6
CML
2
TXOUT
7
+5V
3
CI
8
DG
4
/EXHS
9
+24VA
5
DPON
SURGE
PROTECTION
CIRCUIT
HS
DETECTOR
DIODE
BRIDGE
ACTIVE
CHOKE
HI
LO
CI
DETECTOR
+5V
TXA2
MODEM
(FM336PLUS)
RIN
TXA1
VREF
RXIN
RXIN
TXOUT
CONTROL
LIU
HI
HI
CI
CI
EXHS
EXHS
CML
CML
CML
PB_DATA
BZOUT
OA-2000
SPMUTE
VOLC
VOLB
VOLA
LO
LO
TXOUT
+5V
+24VA
DG
LINE
EXT.TEL
SPEAKER
CI
IC10
LOGIC IC
Fig. 18
Содержание AM 900 - Digital Office Laser Copier
Страница 120: ...AM 900U 6 13 13 Control PWB parts layout Bottom side The CONTROL PWB of the model employs lead free solder F3 F5 F7 F4 ...
Страница 122: ...AM 900U 6 15 2 LIU PWB parts layout Top side The LIU PWB of the model employs lead free solder ...
Страница 123: ...AM 900U 6 16 3 LIU PWB parts layout Bottom side The LIU PWB of the model employs lead free solder ...