Panasonic KX-FT901CX-B, Service Manual

Page: 118 / 183

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 IC1 pin 124 becomes a high level, and Q4 and Q1 go ON as a result. +24 V is supplied to the
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.
Stepping Motor Phase Pattern
Function Mode Phase Pattern Speed
Copy Fine/Half Tone 1-2 432 pps
Super Fine 1-2 216 pps
FAX STD 2 432 pps
Fine/Half Tone 1-2 432 pps
Super Fine 1-2 216 pps
——— Paper Feed 2 432 pps
When the motor is OFF, gate array IC1 pin 124 becomes a low level and Q4 and Q1 also turns OFF. Instead of +24V, +5V is
supplied through D1 so that the motor is held in place.
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KX-FT901CX-B / KX-FT903CX-B / KX-FT901CX-W / KX-FT903CX-W / KX-FT901CX-S / KX-FT903CX-S