March 2000 © TOSHIBA TEC
7-81
DP120F/DP125F Circuit Description
4.2 Dial Pulse Generation Circuit
US/CA/TW models
The dial pulse generation circuit consists of the diode bridge (DB1), photo-coupler (PC1), the I/
OP-1 GA (IC7) on the Main PBA, and other peripheral devices. It generates dial pulses in
facsimile transmission and dialing outside.
The I/OP-1 GA causes the CML1 signal to be HIGH to connect the line to the MODEM side. To
achieve a dial make, the I/OP-1 GA causes the LD1 signal to be HIGH to turn on Q53. This
allows the photo-coupler to turn on and allow current to flow through the diode bridge for send-
ing dial pulses to the line.
Fig. 7-4-5
07-04-02
Signal Name
Type
Active
Description
Destination
LD1
O
H
Line 1 Dial Pulse Generate Signal
Q53
Summary of Contents for DP120F
Page 1: ...PLAINPAPERFACSIMILE File No 31200001 R0112216901 TTEC ...
Page 401: ...DP120F DP125F Circuit Description 7 92 March 2000 TOSHIBA TEC 07 05 00 Fig 7 5 1 ...
Page 656: ...DP120F DP125F Troubleshooting 11 44 March 2000 TOSHIBA TEC ...
Page 700: ...DP120F DP125F Appendix 12 2 March 2000 TOSHIBA TEC 1 2 Error Count List ...
Page 701: ...March 2000 TOSHIBA TEC 12 3 DP120F DP125F Appendix 1 3 Function List for Maintenance ...
Page 702: ...DP120F DP125F Appendix 12 4 March 2000 TOSHIBA TEC 1 4 Drum Unit ...
Page 703: ...March 2000 TOSHIBA TEC 12 5 DP120F DP125F Appendix 1 5 Memory Dump List ...
Page 706: ...SHUWA SHIBA PARK BLDG A 2 4 1 SHIBA KOEN MINATO KU TOKYO 105 8524 JAPAN ...