Toshiba GD-1210 Manuale Utente

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GD-1210/1250/1270/1160/1260
ELECTRICAL CIRCUITS
4 - 7
4
4.2.3
Dial pulse generation circuit
NA/TW models
 Fig. 4-7
The dial pulse generation circuit consists of the diode bridge (DB1), photocoupler (PC1), the ASIC 
(IC29 [IC26]) on the FAX board and the other peripheral devices. It generates the dial pulses in the FAX 
transmission and dialing to the outside.
The ASIC makes the CML1 signal become HIGH to connect the line to the MODEM side. To generate 
the dial pulse, the ASIC makes the LD1 signal become HIGH to turn ON Q53. This allows the photo-
coupler to come on and the current flows through the DB1 to send the dial pulses to the line.
* Values in [ ] are for GD-1250/1270 in case that the descriptions vary between GD-1210 and GD-
1250/1270.
Signal Name
Type
Active
Description
Destination
LD1
O
H
Line 1 Dial Pulse Generation Signal
Q53
CML1
LD1
3
4
4
3
1
2
AG
Q51
CN10
CN11
Lb
La
Line
0
1
0
1
3
10
8
12
4
9
1
+12V
RLY2
CML relay
4
3
3
4
21
20
FAX board
NCU board
IC29
[IC26]
ASIC
Ring signal
detection
circuit
CN9
CN501
-
PC1
DB1
+
~
~
Q53
SG
+5V
a2
b2
External
telephone
3
4
C5
R4
08/04