Commodore 8250LP - VII. DRIVE; Electrical Characteristics

C.
Electrical
-
Readings
at
21°C
and
nominal
volta~e
unless
othen.ise
specified.
1.
Dri
ve
~Iotor
H3-'C.
stall
current
~t3-'C.
running
current
Typical
current
Start
time
2.
Stepping
:'1otor
Stepper
Motor/2
Phase
(12
V)
3.
Read/Write
Channel
Head
Resistance/1NDUCTANCE
Resistance
R\'i1
or
R\y-2
to
CT
Inductance
R\i
at
full
coil
Resistance
Erase
to
C.T.
Inductance
Erase
Performance
900
MA
400
HA
280
K.\.
1
sec
m3-'C.
1-35
320
-30
~1A
37
±
30%
ohms
2
±
3aYo
mH
8.0
_ 30%
ohms
3.3
_
30%
1J.H
Test
criteria:
Head
and
Carriage
Rotational
speed
300
rpm
Track
radius
at
track
77
Fre~uency
125
kHz
Load
pad
pressure
17
±
3
grams
',rri
te
current
6.3
::
0.2
M.A
p-p
Average
read
amplitude
after
writing
1.3
mv
p-p
min.
Resolu~ion
60%
min.
VIII.
I~T£RFACS
A.
Introduction
This
specification
describes
the
requirements
of
the
physical
and
electrical
interface
with
the
JU-570
Diskette
Drive
unit.
The
physical
interface
section
specifies
the
mechanical
requirements
as
well
as
lis~s
recommended
parts.
The
electri-
cal
interface
defines
the
functional
as
well
as
timing
relationships
required
of
each
I/O
pin.
(Fig.
1)
(5)