UX-A1000U
[3] Circuit description of TEL/LIU PWB
(1) TEL/LIU block operational description
1) Block diagram
2) Circuit description
The TEL/LIU PWB is composed of the following 7 blocks.
1. Speech circuit section
2. Dial transmission section
3. Speaker amplifier section
4. Ringer circuit section
5. CI detection circuit
6. Signal/DTMF transmission level & receiving level
7. External phone off-hook detection (HS) section
3) Block description
1. Speech circuit section
•
The receiver volume is an electronic volume type, this model is
switched in 3 steps.
2. Dial transmission section
•
D.P. transmission: The CML relay is turned on and off for control in
the DP calling system. (Refer to the attached sheet.)
•
DTMF transmission: It is formed in the modem, and is output.
3. Speaker amplifier section
•
Ringer volume
:It is controlled by the combination of the
attenuator value of the LINE DRIVER in the
modem and the ringer sending level sent from
the modem.
•
Speaker volume
:It is controlled by the attenuator value of the
IC3 and IC16 (VOL-A.B.C).
4. Ringer circuit section
•
The ringer sound is formed in the tone of modem when CI signal is
detected. The amplifier circuit drives the speaker of the main body.
5. CI detection circuit
•
CI is detected by the photo coupler which is integrated in series in
the primary side TEL circuit well proven in the existing unit.
6. Signal/DTMF transmission level & receiving level
•
Signal transmission level setting: ATT -8 dB Circuit output: -11.5 dBm.
• DTMF transmission level setting: HF -2.5 dBm LF -4.0 dBm
Thus, set the level.
Fig. 6
5 – 13
DAC
LPF
DAC
H
L
CI DETECTOR
HS
DETECTOR
SPEAKER
LINE
EXIT
+24VL
DG
CONTROL PWB
TEL/LIU PWB
RX
TX
TEL MUTE
(H:MUTE)
Q102
IC101B
Q103
IC101D
IC101C
IC101A
IC8
IC3
0,1
0,0
1,0
1,1
RTLOOP
ADC
SIN
MIC
/LINE
SELECT
SP OUT
ENABLE
MIC ENABLE
(20438 I/A)
LINE IN ENABLE
LINE OUT ENABLE
0,20,25,30dB
LINE
SELECT
1,1
0,0
1,0
0,+4dB
SOUT
HS
SPKRP
MICP
LINEIN
LINE
OUT
MUTE,0,-6,-12dB
IC16 SCE214V
FAX CONTROLLER
DTMFMUTE
RCVOL
SP MUTE
TEL MUTE
CI
CML
MIC MUTE
VOL-A
VOL-B
VOL-C
SPOUT
BZOUT1
SP MUTE
TEL IN
RXIN
TXOUT
MIC MUTE
(H:MUTE)
CML
SIGTX
SIGRX
TELOUT
0,6dB
HANDASET
7. External phone off-hook detection (HS) section
Line current detection will be switched to ON (LOW) when the main
unit or the external phone is off the hook. When the HS signal is turned
on at CML OFF, the external phone is considered to be off the hook
and, at CML ON, the HS signal is constantly turned on (if connected).
4) Signal selection
The following signals are used to control the transmission line of TEL/
FAX signal. For details, refer to the signal selector matrix table.
[Control signals from output port]
Signal Name
Description
CML
Line connecting relay and DP generating relay
(The circuit is located
H: Line make
in the TEL/LIU PWB.)
L: Line break
SP MUTE
Speaker tone mute control signal
(The circuit is located
H: Muting (Power down mode)
in the control PWB.)
L: Muting cancel (Normal operation)
Handset reception mute control signal
TELMUTE
H: Muting
L: Muting cancel
Handset receiver volume control signal
RCVOL
DTMFMUTE
(The circuit is located
in the control PWB.)
Note: The DTMF sending listed above is DTMF signal
sending in the handset OFF-HOOK mode.
Volume
High
Middle
Low DTMF sending
RCVOL
L
H
H
H
DTMFMUTE
L
L
H
H
Summary of Contents for UX-A1000
Page 51: ...UX A1000U 3 13 M E M O ...
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Page 82: ...UX A1000U Control PWB parts layout Bottom side 6 9 FU101 FU100 ...
Page 86: ...UX A1000U TEL LIU PWB parts layout Top side 6 13 TEL LIU PWB parts layout Bottom side ...
Page 91: ...UX A1000U P IN YELLOW FU1 GREEN 3 3V Printer PWB parts layout Top side 6 18 ...
Page 92: ...UX A1000U Printer PWB parts layout Bottom side 6 19 ...
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