User Guide

GD-1210/1250/1270/1160/1260 © 2006 - 2011 TOSHIBA TEC CORPORATION All rights reserved
ELECTRICAL CIRCUITS
4 - 12
EU/AU/AS/C models
Fig. 4-12
The CI detection circuit consists of the photocoupler (PC1), ASIC (IC29 [IC26]) on the FAX board and
other peripheral devices to detect a ring signal input from the telephone line.
The ASIC makes the CML1 signal become LOW to connect the CI detection circuit to the line. When a
ring signal is input from the telephone line, the photocoupler is repeatedly turned ON/OFF. This allows
Q5 to be turned ON/OFF and the CI1 signal to become a pulse signal and input to the ASIC on the FAX
board, thereby detecting the ring signal.
* 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
CI1 I - Line 1 CI Detection Signal IC29 [IC26]
CN3
Lb
La
Line
0
1
0
10
3
121
4
9
1
+12V
RLY3
CML relay
CML1
Q4
3
4
3
3
21
417
NCU board FAX board
IC29
[
IC26
]
ASIC
CI1
17
1
2
4
3
AG
Q5
SG
5VPS
R34
R35
CN4
CN501
PC1
ZD3ZD2C8 R4
D2
08/04