Toshiba GD-1250, GD-1260, GD-1270, GD-1160, GD-1210 service manual Line 1 Dial Pulse Generation Signal

EU/AU/AS/C models

NCU board

+12V RLY3

CML relay

112

+5V

Q4

3

FAX board

3 CML1 21

4 Lb 4

1 5

0 3

6 1

AG

IC29

[IC26]

Line

External telephone

	3	La	1	8
			9	10
CN3			0
	2	a2
	5	b2

IC1

42

Q6

SG

T1

AG

Ring signal

detection

circuit

4

Line path switching circuit

CN4

CN501

4 LD1 20

ASIC

Fig. 4-8

The dial pulse generation circuit consists of the photocoupler (IC1), 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 pulses, the ASIC makes the LD1 signal become HIGH to turn ON Q6. This allows the photocou- pler to come on and the current flows through the line for sending a dial attempt.

Signal Name	Type	Active	Description	Destination
LD1	O	H	Line 1 Dial Pulse Generation Signal	Q6

*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
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