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© 2003 - 2008 TOSHIBA TEC CORPORATION All rights reserved GD-1150/1151/1200/1201/1160/1260
ELECTRICAL CIRCUITS
4 - 9
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4.2.3 Dial pulse generation circuit
NA/TW models
Fig. 4-9
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-1151/1201 in case that the descriptions vary between GD-1150/1200 and
GD-1151/1201.
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
08/03