Table of Contents
Advertisement
.0
U
3D
U
2. VOlT
CURRENT
2D
IAMPSI
1.5
1.0
•
2
START
CURRENT
lOAMI'S TYPICAL
INOTE 11
\tv
\A
4.0 AMPS
MOTOR AT SPEED
PLUS SEEKING WITH PEAKS
OF DURATION LESS THAN
300 us(NOTE 3)
2DAMPSMOTOR
' - -_....J____
100 rnA for on track
•
•
AT SPHD HEADS
IN LANDING ZONE
INOTE
2)
•
10
IZ
ToME
ISECI
FIGURE 1-3
'-'--------
MOTOR O"'lY - - . /
II
II
DC DRIVE MOTOR CURRENT PROFILE
The start sequence for the Q2080 with the DC motor option has four steps. Each step uses a different amount of
24 volt current.
1. During start up, the motor takes 3.0 amps and the actuator is disabled so that the entire 24 volt current is used
in the motor. This state lasts until the microprocessor senses that the motor is
9ODJo
of full speed, typically twelve to
sixteen seconds.
2. After the motor reaches 90% of full speed the microprocessor limits the motor to 2.0 amps. There is a period
of one to two seconds when the motor is in the lower current limit and actuation is disabled.
3. When the drive reaches 92% of regulated speed, the actuator begins its recalibration sequence. The motor
continues to draw 2.0 amps and the actuator draws 2.0 amps. At the end of each buffered seek, this 4.0 amp level is
topped by a spike of less than 4.0 amps and less than 300 us duration. The recalibration current level is repeated dur-
ing normal seeking.
4. After recalibration and the motor has reached full speed, the actuator remains on track using 100 rnA of 24
volt current and motor current drops to 1.75 amps. The total motor and actuator current is then 1.85 amps. This is
the nominal drive current during the read/write and quiescent states.
1.2.9 AIR FILTRATION
The Model Q2080 is a Winchester type drive, and as such, the heads fly very close to the media surface. The
nominal flying height is eighteen micro inches or roughly 1,600 times smaller than the period at the end of this
sentence.
REV A (01/84)
1-4
Advertisement
Table of Contents
