Toshiba GD-1260, GD-1250, GD-1270, GD-1160, GD-1210 Line 1 CI Detection Signal IC29 IC26

EU/AU/AS/C models

NCU board

	+12V	RLY3
		CML relay
	1	12
4 Lb	4	1

Q4

3

FAX board

3 CML1 21

Line

	0	3
CN3		C8	R4	ZD2 ZD3
	1
3 La	9	10
	0

D2

AG

5VPS

1 4 R34

PC1		17
2	3

Q5

R35

SG

CN4

CN501

17 CI1 4

IC29

[IC26]

ASIC

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.

Signal Name	Type	Active	Description	Destination
CI1	I	-	Line 1 CI Detection Signal	IC29 [IC26]

*Values in [ ] are for GD-1250/1270 in case that the descriptions vary between GD-1210 and GD- 1250/1270.

GD-1210/1250/1270/1160/1260	© 2006 - 2011 TOSHIBA TEC CORPORATION All rights reserved
ELECTRICAL CIRCUITS

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