Motor Drivers - Philips DVDR985 Technical Training Manual

Motor Drivers

The motor drivers each receive an error or con-
trol voltage. There are 6 motor drivers in this
unit: the Focus Motor Driver, the Radial Motor
drivers, the Turn table Motor Driver, the Tilt
Motor driver, the Sled motor Driver and the Tray
motor Driver.
Focus Motor Driver
The Focus motor is located on the OPU. It con-
trols the up and down motion of the laser's lens.
An error signal is produced by the MACE3
Microcomputer. The FO signal comes into Pin 3
of 7302. The Driver circuit amplifies the signal
and converts it to a balanced output at Pins 1
and 2 of IC7302. The Output goes to the OPU.
Radial Motor Driver
The Radial motor is located on the OPU. It con-
trols the side to side motion of the laser's lens.
this is used in conjuction with the Sled Motor for
tracking. An error signal is produced by the
MACE3 Microcomputor. The RA signal comes
into Pin 25 of 7302. The Driver circuit amplifies
the signal and converts it to a balanced output at
Pins 26 and 27 of IC7302. The Output goes to
the OPU.
Turn Table Motor Driver
The Turn table Motor is a standard three phase
motor simular to what is found in VCR capstan
motor circuits.The driver IC,7301, receives two
control voltages. The Motor Error signal comes
into Pin 22. There is a Motor Enable switching
voltage coming into Pin 23. A three phase drive
signal is provided to the motor. Three hall ele-
ments feed speed and phase data back to the
motor driver IC. These signals are amplified.
Three FG signals are output to the
Encoder/Decoder from Pins 16, 17, and 18.
Tilt Motor Driver
The Tilt Motor driver contains two signal paths.
The motor has two field windings. The Tilt Motor
has two error voltages supplied by the MACE3.
The Tilt Output Cosine and Tilt Output Sine sig-
nals go to Pins 17 and 18 of 7306. The Signals
are amplified and provided to the motor on Pins
12-5 of IC7306.
Sled Motor Driver
THe MACE3 produces the SL control voltage for
the driver circuit. The Sled motor drive signal is
provided to the Sled Motor by 7302. The SL sig-
nal comes into IC7302 on Pin 20. A control volt-
age is developed and amplifiers produce the
drive voltages on Pins 17 and 18. These are
connected to 1302 on Pins 7 and 8.
Tray motor Driver.
Trayin, and Trayout logic control lines are
received from the MACE3 and a motor drive sig-
nal is provided to the Tray Motor. The logic con-
trol signal comes into IC7302 on Pins 15 and 16.
A control voltage is developed and amplifiers
produce the drive voltages on Pins 12 and 13.
These are connected to 1301 on Pins 3 and 4.
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