1.15.3
Sp in d l e D r ive System
The spindle drive system consists of a spindle assembly driven through a drive belt by a brushless
D.C. motor/tachometer.
The servo electronics required for speed control are located on the printed circuit board.
The control circuitry contains an interface control line. When the drive motor control interface line is
false (high), the drive motor is allowed to come up to speed.
READY
INDEX SENSOR
L.E.D.'S ~
CONTROL
LOGIC
INDEX
DISK CHANGE
TWO SIDED
D.C.
STEPPER
MOTOR
WRITE PROTECT
TRACK 00
WRITE PROTECT
SENSOR
+
L.E.D.
IN USE
INDEX DETECTORS
SIDE SELECT
HEAD CARRIAGE
AND STEPPER
BAND
ASSEMBLY
WR ITE
PROTECT
DETECTOR
DRIVE SELECT
SPINDLE
MOTOR
CONTROL
M OTOR CONTRO L
D.C. DRIVE
MOTOR
WRITE GATE
WRITE DATA
WRITE
LOGIC
CURRENT SWITCH
READ
LOGIC
READ DATA
DIRECTION
STEPPER
MOTOR
CONTROL
STEP
Figure 1-2
TM848 Disk Drive Functional Block Diagram
1.15 4
Po s i t i o ne r Control
The head positioning system uses a bipolar-driven motor drive, which changes one phase for each
track advancement of the read/write carriage. In addition to the logic necessary for motor control, a
gate is provided that inhibits positioner motion during a write operation.
1.15.5
Data E l e c t r o n ics
Information can be recorded on the diskette by using a double-frequency code. Figure 1-3 illustrates
the magnetization profiles in each bit cell for the number sequence shown for FM recording.
1-9
Содержание TM848-1
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Страница 81: ...APPENDIX I PRINTED CIRCUIT BOARD S CHEM A T ICS AND ASSEM B LY DRAW IN G S ...
Страница 88: ...APPENDIX II RECOM M E N D E D SPARE PARTS LIST ...
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