Stepping Motor Drive Section - Panasonic KX-F900 Service Manual

I KX-F900 1
4-4. STEPPING MOTOR DRIVE CIRCUIT
(1) Function
Two individual stepping motors are used for transmission and reception. They feed document or recording paper
synchronized for reading or printing.
(2| Circuit Operation
During motor drive, gate array IC1 pin 77/pin 71 becomes high level, Q2/Q4 are turned ON, and QI/Q3 go ON as a result,
+24 V issuppliedto the motorcoil.
Steppingpulsesare outputform gate array IC1, causingdriver IC7/IC8 to go ON. The motorcoil isenergized sequentially in
2 phaseincrements, w hichcausesa 1-step rotation.Rotationof 1-step 0.13mm of recordingpaperor documentpaper.
Timingchart isbelow.
TM0(RM0)
TMI(RM1)
TM2(RM2)
TM3(RM3)
Timing Chart
Function
Copy
FAX
Stepping Motor Phase Pattern
Mode
STD
Fine/Half Tone
Super Fine
STD
Fine/Half Tone
Super Fine
Paper Feed
Drive Phase
Pattern
1-2
1-2
1-2
1-2
1-2
1-2
1-2
Speed
434 pps
434 pps
217 pps
434 pps
434 pps
217 pps
217 pps
1-2. Phase (Asic TM0-TM3, RM0-RM3 output)
GATE ARRAY
(let)
TXE
(RXE) '
TM0
(RMO)
TM1
(RM1)
TM2
(RM2)
TM3
(RM3)
Circuit Diagram
(71) (_
( )
IC7(IC8)
73 4
(67) (4)
74 5
(68) (5)
75 6
(69) (6)
7(_ 7
(70) (7)
Q
Q
Q
Q
ittt
1
I!
+5V
R43 +24v ,,_
(R_5)' 1
(Q3)
(R46)
D3
( )
CN9
4
5
o-
3
'(Igl o-
11 2
(11) o-
10 1
o-
) (10)
Phase 0 - -
Phase 1
m
Phase 2
Phase 3
Ol
(02)
max. _/434 (sec)
(ON 10)
_ RECEPTION)
TRANSMISSION
MOTOR
m
m m m
m mm
m
n
m m m
mm m
um
mm
I
I
m
mm
mm
When the motor is OFF, gate array IC1 pin 77/pin 71 becomes low level and Q2/Q4 are turn OFF. This causes Q1/Q3 to
also go OFF and inserted of +24V, +5V is supplied through DI/D2 so that the motor is held in place.
- 142-