Toshiba GD-1160 用户手册
GD-1210/1250/1270/1160/1260
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ELECTRICAL CIRCUITS
4 - 10
EU/AU/AS/C models
Fig. 4-10
The line current detection circuit consists of the line current detection IC (IC2), ASIC (IC29 [IC26]) on
the FAX board, and the other peripheral devices. It detects a dial tone and the hook status of the exter-
nal telephone from the current flowing through the line.
the FAX board, and the other peripheral devices. It detects a dial tone and the hook status of the exter-
nal telephone from the current flowing through the line.
When a dial tone is input from the telephone line, current flows through the line. The line current detec-
tion IC sends REVA1 and REVB1 to the ASIC as pulse signals. This allows a dial tone to be detected.
tion IC sends REVA1 and REVB1 to the ASIC as pulse signals. This allows a dial tone to be detected.
* 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
REVA1
I
-
Line 1 Current Detection Signal
IC29 [IC26]
REVB1
I
-
Current Reverse Line 1 Current Detection
Signal
IC29 [IC26]
CN3
Lb
R26
Line
REVA1
REVB1
19
4
20
1
2
8
7
19
20
2
3
NCU board
FAX board
IC29
[IC26]
ASIC
CN4
CN501
IC2
Line current
detection
IC
08/04