Sony Mavica MVC-FD85 Training Manual page 45

Spindle Motor Drive Signals
Signal Name Location
FPTS CN701/pin 18
HDS CN701/pin 17
FDD_Gnd CN701/pin 16
FDD_Gnd CN701/pin 15
Clock CN701/pin 14
MC CN701/pin 12
Index CN701/pin 11
FDD_5V CN701/pin 10
FDD_5V CN701/pin 9
Index
T
1
Clock
2
CH1!2.00 V=
CH2!5.00 V= MTB1.00 s- 1.02dv ch1-
Spindle Motor Signals
Name
Index CN701/pin 11
Clock CN701/pin 14
Time Base = 1 second/div.
Voltage - Disc Comments
not spinning
5Vdc
4.8Vdc
0Vdc
0Vdc
0Vdc Rotation signal
5Vdc
5Vdc From drive
5Vdc
5Vdc
Spindle Motor
Drive Signal
(clock)
PKD
Location Voltage
5Vp-p
4Vp-p
43
Stepper Motor Drive
The stepper motor is connected to the read/write heads and can move
the heads from the outside track 00 to the inside data area of the floppy
disc. After a disc is detected, the spindle motor turns and the stepper
motor is instructed to move the heads to track 00.
Two out-of-phase stepper motor drive signals, from the main FC-72 board
are applied to motor coils A and B at CN701/pins 1-4 for movement. Each
motor coil that receives the signal is 16 ohms. All four signals must be
present for the stepper motor to rotate.
Stepper motor Dive Signals
Signal Location
Name
PA CN701/pin 1 0Vdc
PB CN701/pin 2 0Vdc
PNA CN701/pin 3 0Vdc
PNB CN701/pin 4 0Vdc
The following waveforms show two of the four drive signals going to coils
A and coil B.
pkpk 8.33 V, freq
T
PA
1
PNB
2
CH1!5.00 V=
CH2!5.00 V=
Voltage no motor Description
movement
+ drive to coil A
+ drive to coil B
- drive to coil A
- drive to coil B
666 Hz
PKD
MTB20.0ms- 1.02dv ch1+