Bernina 1230 - Component Description; Power, Display, and Control Prints

Description
The electronics
of the model
1230
sewing
S-1230
control
print
machine
is essentially
located
on three
large
The complete
sewing
machine
control
is located
printed
circuit
boards;
the power
print
L-4200,
the
on the
S-1230
control
print. The
S-1 230
control
control
print S-1230
and
the display
print
A-1 230
print is located
on
the A-1
230 print
from the
rear.
(compare
to the
block schematic
diagram).
The
The most
important
control
elements
are
the
tasks
of the
3 units
correspond
to
the known
microcomputer,
and the
power
drive for
the step
functions
of
L-4200,
S-4200
and A-4200
prints
motors.
A
new feature
over
model
1130 is that
the
from the
model
1130.
bobbin
winder
motor is
also controlled
by
the
microprocessor.
The bobbin winder motor speed
1-4200
powerprint
can
now be
controlled
from
the foot
control.
The
L-4200
power
print is
mounted
above
the
The S220
service
switch
on print
S-1 230
is a
motor
on the
rear side
of sewing
machine.
The
service
aid. This
switch
has two
positions:
normal
circuit
components
on
the L-4200
have
the follow-
sewing
operation,
and
service
position.
In the
ing functions:
service
position,
several
buttons
and
diodes
on
-the
display
panel
are assigned
other
functions.
- Motor
control:
This
allows
the service
technician
to
execute
The
main
motor control
operates
with the
mains
necessary
adjustment
and
testing
functions
using
voltage.
The main
motor
is a
DC motor
with
the
display
panel (refer
to
the special
section
pulse-width
modulated
speed
control.
The
service
programme).
The service
switch
must
closed
loop control
circuit
on the
small
R-4200
always
be set into
the sewing
position
for
normal
print is
located
on the
power print.
sewing
operations.
All circuit
components
for the
motor control
The microcomputer
on print
S-1 230
receives
an
operate
at dangerous
voltage
levels,
analog
signal
from
the foot
control,
which it
then
The safety
regulations
must be
adhered
to.
converts
into a
digital
signal and
transmits
to print
R-4200 as setpoint
for the motor
speed. The
- Power
supply:
R-4200
print controls
the
motor
speed
to the
Generates
the
following
D.C.
voltages:
speed specified
by the S-print,
using
a setpoint
-
- 30V
for the
step motors
actual
value
comparison.
When
the foot
control
is
-
5V for
the logic
circuitry
on the
S-1 230
and
released,
the
setpoint
goes
to zero,
the brake
is
A-1230
prints
actuated
from the
microcomputer
on the
S-print
- 6V
for the sewing
light
via the R-4200
print,
and
the motor
is rapidly
- 30V
for the
bobbin
winder
motor
braked.
Components
are
protected
from
overload,
in
Signal
transfer
between
the
S-1230
and R-4200
the case
of faults,
by
three fuses
F 150,
F 151
print is
realised
using a
4-pole cable.
Signal
and F
152. If a
fuse blows
only
original
replace-
transfer
is
realised
through
an opto-coupler
ment fuses,
with
the correct
rating
may be
used.
providing
electrical
isolation
and thus
eliminating
dangerous
voltage
levels
from
the foot
control
A-1230
display
print
and the
S-1230
control
print.
The
display
section
is mounted
directly
behind
the
The
step motors
are
in random
positions
when
operating
control
panel.
The display
and
ope-
sewing
machine
is switched
on.
Random
values
rating control
elements
are soldered
onto
the L-
can also
be in the
microcomputer
control
shaped
printed
circuit.
memory.
In
order
to have a
defined
state, the
step
A time
multiplex
control
allows
the numerous
motors
are rotated
into
their calibrated
position
LEDs
and control
elements
to
be connected
to
the
by a
microcomputer
command,
and
the position
open loop
control
on the
S-1 230
control
print
value is
set to zero
in the
microcomputer
memory.
using
only
16 connection
lines.
This
starting
state
allows
the selection
and
sewing
of any stitch programme.
6 1230