Panasonic KX-FC971CX-S Service Manual page 141

8.4.5. 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, gate array IC10 pin 124 becomes a high level, and Q13 and Q14 go ON as a result. +24 V is supplied to
the motor coil.
Stepping pulses are output from gate array IC10, causing driver IC11 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 IC10 pin 124 becomes a low level and Q13 and Q14 also turns OFF. Instead of +24V, +5V is
supplied through D13 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
141
KX-FC971CX-S / KX-FGA521CX-S
Speed