Toshiba DP120F, Service Manual

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March 2000 © TOSHIBA TEC 7-43 DP120F/DP125F Circuit Description
3.10 TX Motor Drive Circuit
The TX motor drive circuit consists of the PTC GA (IC45), Motor driver (IC70), and other periph-
eral devices. It drives the stepping motor connected to CN8 on the Mother PBA in 1-2 phase
excitation/2 phase excitation mode to transport a document in facsimile transmission and copy
mode.
The PTC GA outputs the MT1A, B, AX and BX signals and the MT1C0 and 1 signals to the
Motor driver. The Moter driver generates the OTXA, B, AX and BX signals based on the input
signals and outputs them to the TX motor. The TX motor is driven in steps according to the
input drive phase signals.
Fig. 7-3-10
07-03-10
Signal Name Type Active Description Destination
MT1A, B, O - Tx Motor A/B/AX/ BX Phase Signal IC70
AX, BX
MT1C0, 1 O - Tx Motor Current Control 1/2 Signal Q2, 257
OTXA, B, O - Tx Motor Drive A/B/AX/ BX Phase Signal TX motor
AX, BX