Panasonic KX-FT937LA-B Service Manual page 25

6.4.5. Stepping Motor Drive Circuit
1. Function
One individual stepping motor is used for transmission and reception. It feeds the document or recording paper synchronized
for reading or printing.
2. Circuit Operation
During motor drive, ASIC IC1 pin 124 becomes a high level, and Q2 and Q1 go ON as a result. +24 V is supplied tothe motor
coil.
Stepping pulses are output from gate array IC1, causing driver IC7 to go ON. The motor coil is energized sequentially in 2
phase increments or 1-2 phase increments, which causes a 1-step rotation. A 1-step rotation is 0.13mm of recording paper or
document paper. The timing chart is below.
Copy
FAX
———
When the motor is OFF, gate array IC1 pin 124 becomes a low level and Q2 and Q1 also turns OFF. Instead of +24V, +5V is suplied
through D501 so that the motor is held in place.
Stepping Motor Phase Pattern
Function Mode
Fine/Photo
Super Fine
STD
Fine/Photo
Super Fine
Paper Feed
Phase Pattern
1-2 432 pps
1-2 216 pps
2 432 pps
1-2 432 pps
1-2 216 pps
2 432 pps
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KX-FT937LA-B
Speed