Toshiba DP120F Service Manual page 391

EU/AU/ASIA/HK models
07-04-02E
Fig. 7-4-6
The dial pulse generation circuit consists of the photo-coupler (IC1), 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
generate dial pulses, the I/OP-1 GA causes the LD1 signal to be HIGH to turn on Q6. This
allows the photo-coupler to turn on and allow current to flow through the line for sending dial
make.
Signal Name Type Active Description Destination
LD1 O H Line 1 Dial Pulse Generate Signal Q6
DP120F/DP125F Circuit Description 7-82 March 2000 © TOSHIBA TEC