GD-1060 CIRCUIT DESCRIPTION
5 - 18
January 2001 © TOSHIBA TEC
Fig. 5-4-10
The CI detect circuit consists of the photo-coupler (PC1), I/O port GA-2 (IC6) on the Main PWA, and other
peripheral devices to detect a ring signal input from the telephone line.
The I/O port GA-2 causes the CML1 signal to be LOW to connect the CI detection circuit to the line. When
a ring signal is input from the telephone line, the photo-coupler repeats turning on and off. This allows Q5
to turn on and off and the OCI1 signal to be a pulse signal and input to the I/O port GA-2 on the Main PWA,
thereby detecting the ring signal.
CN3
Lb
La
Line
0
1
0
1
+12V
RLY3
CML relay
CML1
Q4
3
4
3
3
73
19
17
NCU PWA
Main PWA
IC6
I/O port GA-2
OCI1
17
AG
Q5
SG
5VPS
R34
R35
CN4
CN3
PC1
ZD3
ZD2
C8
R4
D2
05-04-05-E
ASD/AUD/CND/MJD models
Signal Name
I/O
Active
Description
Destination
OCI1
I
-
CI Detect Signal
I/O port GA-2