Dual CS 731 Q User manual

Dual
CS
7310
Service
Manual

Fig. 1 TA-Anschlußschema / Audio Connection Diagram / Schema de branchement / Esquema de conexion del fono captor
а)
mit
DIN-Stecker
5-polig
/
with
DIN-plug
5
pin
b)
mit
Cynchstecker
/
with
phono
plug
avec
fiche
DIN
5
pöles
/
con
enchufe
DIN
de
5
poles
avec
fiche
cynch
/
con
enchufe
Cynch
rechter Kanal
right channel
canal droit
сапа! дегесћо
rot / гей / rouge / rojo
rechter Kanal / right channel
Canal droit / Canal derecho
rot (schwarz) /red (black)
rouge (noir) / rojo (negro)
linker Kanal / left channel
|
Canal
droit
/
Canal
izquierdo
1 gelb (weiß) / yellow (white)
| jeune (blanc) / amarillo (blanco)
|
= 4
f
у
Tonabnehmerkabel
гд
PS
Ns «| Tonearm audio cable E) |
Cable
de
BF
M
Ee
Сава ве чопекаркег ! Г. Cynch-Tonabnehmerkabel
l
|.
Pick-up
lead
with
Cynch
plug
linker Kanal 1 1 Cable de BF avec fiche Cynch
left
channel
|
|
Cable
del
fonocaptor
con
canal gauche Ї | enchufe Cynch
canal izquierdo Masse draht / Mass lead !
мей / white / blanc / blanco Mass cable / Masa cable | |
|
| |
Masse rechter Kanal H— Masse linker Kanal
Mass
right
channel
|
I
`
Mass
left
channel
Masse canal droit d | — Masse canal gauche
Stummschaltrelais
тава
canal
derecho!
|
тава
canal
izauierdo
Silent
switch
relay
|
!
Relais — conmutateur Stummschaltrelais ! |
silencieux Silent switch relay ! |
Relé de conmutacion Relais — conmutateur silencieux | |
silenciosa \ Relé de conmutacion silenciosa t. d
scis Р! RN ас ——
roter See =|
rechter Kanal
right channel
canal droit
canal derecho
rot / red / rouge / rojo
1 ] | | | ! 1
| linker Kanal
|
left
channel
| canal gauche
| canal izquierdo
weiß / white / blanc / blanco
Kurzschließer
Muting switch
Court-circuiteur
Ї Dispositivo cortocircuitador
!
1 Masse linker Капа!
1 Mass left channel
|
Masse
canal
gauche
| masa canal izquierdo
blau / blue / bleu / azul
Masse rechter Kanal
Mass
right
channel
Masse
canal
droit
masa canal derecho
grün / green / vert / verde
Masse schwarz
|
Ц
!
Mass black
ol | Masse noir
1----
Masa
negro
1 Masseblech
4) Mass sheet E ZEZA
Prise де masse
chapa de masa
Tonarmkopf
Tonearm head
Téte magnétique
Cabezal
fonocaptor
Kontaktplatte
Contact plate
Plaque de contacts
Placa de contacto
Zb

Contents
т
Ф ‹ ‹ю © ‹© ф® с оо со © оо оо єз 4 4 4 © ®› Ф› Ф Ф Ф Ф лл D WN È
Ф
Technical data
Current type
Line voltages
Drive
Power consumption
Run-up time
Platter
Platter speeds
Pitch control
Speed check
Sensitivity of light stroboscope
for 0.3 % speed deviation
Wow and flutter
Signal-to-noise ratio
Tonearm
Effective tonearm length
Offset angle
Tangential track error angle
Tonearm bearing friction
(related to stylus point)
Tracking force
Pick-up head
Cartridge
Weight
Tonearm connection diagram
Technical data
Block diagram
Direct drive system EDS 920
Wiring diagram
General
Fascia
Motor and drive
Replacing motor electronic system
Replacing motor mechanical system
Pitch control
Stroboscope
Tonearm and tonearm suspension
Fitting a 1/2“ cartridge
Removal of tonearm from bearing frame
Removal of complete tonearm
Replacement of spring housing
Adjustment of tonearm suspension
Anti-skating control
Tonearm cue control
Adjustment point
Replacement of cue control plate
Tonearm control
Continuous play
Starting
Manual start
Muting
Shut-off
End of play shut-off
Adjustment points
Power fuse
Tonearm set down point
Shut-off point
Tonearm lift off height
Pull magnet “start/stop”
Pull magnet “сиеїпд”
Tonearm does not set down
Vertical tonearm movement is inhibited
Platter does not rotate
Tonearm does not set down on edge
Motor does not shut-off
Spare parts list with exploded views
Lubrication instructions
AC 50 or 60 Hz
110 — 125 V and 220 — 240 V
Quartz stabilized electronic direct drive system Dual EDS 920, PLL control
Approx. 4 УУ, motor during play < 50 mW
{until
nominal
speed
is
reached)
approx.
1.8
sat
33
rpm
Non-magnetic dynamically balanced, complete rotary mass detachable approx. 1.5 kg
33 and 45 rpm, electronically switchable, quartz stabilized
In PLL technology, quartz accurate for both speeds, separately adjustable,
range of adjustment + 5.5 96
Quartz accurate, illuminated stroboscope with automatic frequency switch-over
for 33 and 45 rpm
20 graduations per minute
DIN < t0.025 96
WRMS < +0.015%
Rumble unweighted signal-to-noise ratio > 52 dB
Rumble weighted signal-to-noise ratio > 7598
Torsion-resistant “ultra-low-mass” aluminum tonearm, in gimbal 4-point
suspension, tonearm balance weight with tuning anti-resonator
221mm
2604!
0.169 /ст
Vertical < 0.07 mN (0.007 g)
Horizontal <0.15mN (0.015 g)
From 0 — 20 mN (0 - 2 g) infinitely variable with 1 mN (0.1 а)
Calibration in range from 2 — 15 mN (0.2 - 1.5 g)
Detachable, suitable for ultra-low-mass cartridges, with long carrier plate (accessory),
also suitable for cartridges with Dual shap-in mounting and for cartridges with 1/2"
mounting
and
a
weight
of
2
to
9
g
(including
mounting
hardware)
Adjustable overhang: 5 mm
See separate data sheet
Approx. 8 kg

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EDS
920
direct
drive
system
The
newly
developed
direct
drive
system
of
the
CS
731
О
turn-
table
is
a
successful
synthesis
of
our
well-known
motor
principle
and
a
highly
sensitive
electronic
system
which
receives
its
accu-
racy
from
a
quartz
crystal.
The
drive
motor
is
a
DC
motor
with
по
commutator
in
which
commutation
is
carried
out
by
two
Hall
generators
which
detect
the
position
of
the
rotor
equipped
with
an
8-pole
ring
magnet
and
which
also
actuate
the
corresponding
windings
of
the
rigid
flat
coils.
The
synchronously
rotating
mag-
netic
return
circuit
plate
and
the
ring
magnet
enclose
with
a
small
air
gap
the
non-ferrous
coil
arrangement
so
that,
on
the
one
hand,
the
drive
system
displays
an
extremely
uniform
running
characteristic
without
pole
sensitivity
and
which
displays,
on
the
other
hand,
a
high
torque
in
spite
of
the
economical
energy
supply.
After
the
nominal
speed
has
been
attained,
the
energy
supply
required
for
maintenance
of
rotation
is
less
than
50
mW.
Fig.3
Description of function
At
a
motor
speed
of
33
1/3
rpm,
the
200-pole
frequency
genera-
tor
rigidly
coupled
to
the
motor
delivers
a
frequency
of
111
Hz
which
is
amplified
in
the
input
amplifier
and
prepared
in
the
cam
form.
This
signal
is
applied
as
an
actual
value
to
the
PLL
circuit.
An
oscillation
frequency
of
4.608
MHz,
which
is
controlled
by
a
highly precise quartz crystal,
is generated
in the quartz oscillator.
The
actual
reference
frequency
—
that
is
to
say,
the
set
value
—
is
derived from the oscillator
frequency
by a multi-stage
divider.
In
the
PLL
circuit,
the
actual
value
and
set
value
are
compared
with
one
another
as
regards
amount
and
phase.
In
the
case
of
the
slightest
deviation,
a
control
pulse
is
applied
to
the
digital/analog
converter
which
obtains
from
this
an
analog
control
signal
which
is
converted
into
a
current
alteration
in
the
subsequently
connec-
ted
motor
control
circuit.
In
the
drive
motor,
this
current
altera-
tion
causes
spontaneous
stabilization
of
the
minimal
speed
devia-
tion.

The
set
value
necessary
for
the
45
rpm
speed
is
generated
in
the
voltage
divider
by
alteration
of
the
divider
ratio.
For
pitch
control,
а
continuously
variable
control
signal,
with
which
the
control
loop
is
fed,
is
obtained
by
means
of
a
complicated
division
pro-
cess.
Thus the complete control range, like the nominal speeds, is
coupled in a locked-phase relation to the quartz oscillator. The
speed accuracy in the pitch range is practically the same as in the
case of nominal speed. The speed deviation preselected with both
pitch controls is maintained even if the pitch switch is operated
or if the unit is seitched off.
In the speed logic, the display unit of the CS 731 Q obtains from
the actual speed the basic information as to whether the actual
speed of the nominal speed is faster or slower. A further logic sy-
stem activates the plus or minus sign of the display unit. Both
signals are dark at rated speed.
From the digital information on the actual speed, a further
digital /analog converter receives relative and analog information
which is transformed in the cascade switch to an activation voltage
for the 13 digital displays. In the display itself the information is
still completely analog as the individual digits are activated with
differentiated voltages and light up accordingly.
This display is as accurate as it is practical. The power section
supplies the various partial circuits with carefully filtered and
stable operating voltages.
General
The listed item numbers refer to the following spare parts lists
and exploded views.
The cover can be easily withdrawn from the hinged splice pieces.
To
remove
the
turntable,
remove
both
fillister
head
screws
(98)
and the discs (86) with which the mounting plate (197) is screwed
down.
The
turntable
can
be
lifted
out
of
the
bracket
(12)
after
disengaging the three transport locking screws.
Now detach the following plug connections:
1)
Both
single-pole
plugs
(722)
on
power
switch
(106).
2)
The
4-pole
plug
(160)
on
the
solenoid
protective
circuit
(185).
3
The 5-pole female multi-point connector (158) at the display
unit
(35).
4
The 5-pole female multi-point connector (185) at the distri-
butor board (24).
Fascia
To dismantle the fascia, remove both attachment screws (21)
with which the display unit is mounted on the bracket base.
bracket base.
The top of the plate (17) is attached with 3 fillister head screws
(98) and three washers (86) and the bottom is attached with
three cheesehead screws (50).
Fig. 4
Motor and drive
Special
tools
and
measuring
instruments
are
necessary
for
repair
of the Dual EDS 920. Therefore,
work on the motor or the motor
electronic
system should only be carried out by an authorized
Dual service station.
Replacement of the motor electronic system, complete
The
individual
modules
(151/152/153)
are
plugged
into
the
main
board. In addition, they are held by means of supports (154).
Moreover, module 1 is also secured with the fixing screw (159).
When replacing the complete motor electronic system, proceed
as follows:
1) Remove the fillister head screws (97) and the four supports
(154).
2) Remove fixing screw (159) (module 1).
3) Detach the plug connections fo the connection cable — refer
to wiring diagram Fig. 3.
4
Detach the motor electronic system completely from the
mechanical system of the motor and replace it.
Replacement of the mechanical system of the motor
1) Release both threaded pins (19) and withdraw plate cone (22).
2) Remove the complete motor electronic system — see above.
The plug connections of the connecting cable need not be
removed.
3) Remove both fillister head screws (99) and the cog (105).
4) Withdraw the mechanical system of the motor and replace it.
Fig.5
97
14
14
Pitch control
With the pitch control, each of the two rated speeds, 33 1/3 and
45 rpm, can be varied by + 5.5 96. With the seesaw switch (16) at
"ОМ" position, each nominal speed can be altered by means of a
separate potentiometer (14). At the same time, the optoelectronic
display scale (35) indicates the percentage deviation from the
nominal speed.
Independently of the potentiometer setting (14), the speed cor-
responds
with
quartz
precision
to
the
respectively
switched
no-
minal speed, if the seesaw switch (16) is in “OFF” position.
Stroboscope
The
stroboscope
markings
on
the
turntable
edge
are
flashed
from
the diode plate (148) by means of quartz accurate
frequency.
The display
is independent
of power frequency
and does not re-
quire additional
stroboscope
markings
for different
speeds and
line frequencies.

When
the
stroboscope
markings
seem
to
be
stationary
both
по-
minal
speeds
(33 1/3
and
45
rpm)
are
accurately
adjusted.
If
the
markings
seem
to
run
ahead
the
speed
is
higher.
If
the
markings
seem
to
run
back
the
speed
is
lower
than
the
nominal
speed.
By
means
of
the
speed
of
the
apparently
“wandering”
markings
the
speed
selected
with
potentiometer
(14)
can
be
determined
at
high
speeds:
1
graduation/sec.
=
0.9
96
deviation.
After
releasing
the
fixing
screw
(159)
and
removing
both
fillister
head
cap
screws
(96)
the
stroboscope
housing
can
be
removed
(149).
After
re-
moving
the
retainer
piece
(147)
the
three
LED's
(148)
can
be
re-
placed.
Tonearm
and
tonearm
suspension
The
light,
torsion-resistant
all-metal
tonearm
is
twingimbal
mounted.
Suspension
is
by
means
of
four
hardened
and
precision
polished
steel
points
which
rest
in
precision
ball
bearings.
The
tonearm
bearing
friction
is
thus
reduced
to
a
minimum.
Bearing
friction
vertical
0.07
mN
(0.007
g)
Bearing
friction
horizontal
0.15
mN
(0.0159)
as related to stylus point.
This
ensures
extremely
favorable
pick-up
conditions.
Before
setting
the
tracking
force
corresponding
to
the
built-in
pick-up
cartridge
the
tonearm
is
balanced
at
O
position
of
the
tracking
force
scale.
Coarse
adjustment
is
carried
out
by
moving
the
weight
with
stem
(60)
subsequent
fine
adjustment
by
turning
the front knurled
ring on the weight.
The
balance
weight
is
designed
so
that
pick-up
cartridges
having
a
dead
weight
(including
fitting
material)
of
2
—
9
g
can
be
balanced.
The
tracking
force
is
produced
by
tensioning
the
coil
spring
fitted
in
the
spring
housing
(74).
The
rotary
knob
(69)
is
provided
with
a
scale
which
permits
accurate
adjustment
of
the
tracking
force
in
the
range
from
0
—
20
mN
(0
-
2
p)
by
means
of the
marking
dots.
Fitting a 1/2" cartridge
The description of retrofitment for fitting а 1/2“ cartridge (ге-
placement of carrier plate etc.) should be taken from the opera-
ting instructions.
Fig.7
27
52
84
Fig.6
Й
147
146
149
96
Ветоуа! of tonearm from bearing frame
1) Secure unit in repair jig. Remove weight (60). Unscrew ten-
sioning screw (52). Set rotary knob (63) to 0.
Turn unit upside down.Remove hexagon nut (34) and screening
plate (119). Unsolder tonearm leads on muting switch (120).
Unscrew tensioning screw (70). Remove rotary knob (69),
disc (68) and indicator (67).
4) Loosen locking nut (61) and unscrew threaded pin (65).
5) Remove tonearm (30) with bearing (71).
Assembly takes place in reverse order.
2
3|
Removal of tonearm assembly with tonearm bearing
Proceed as follows:
1, Secure unit in repair jig. Set rotary knob (69) to 0. Lock
tonearm (30). Remove weight (60)
2. Turn unit upside down. Remove hexagon nut and screening
plate (119). Unsolder tonearm leads on muting switch (120).
3. Remove retainer disc (91). Remove main lever (167) and
bearing block (166). Remove securing disc (89). Lift off ad-
justing bar (168) and rotary bearing (170) and swivel to motor.
141
187
96
168
190
167 176
97

4.
Disengage
tension
spring
(136).
Release
securing
disc
(90)
and
remove
skating
lever
(134).
5.
Remove
hexagon
nuts
(94).
Remove
countersunk
screw
(138).
Remove
counterbearing
(135)
and
segment
(124).
6.
Retain
tonearm
(30)
and
frame
(63).
Remove
filister
head
cap
screw (88). Remove
tonearm
complete
with tonearm
bearing.
When
fitting
the
tonearm
proceed
in
reverse
order
but
ensure
that
the
threaded
pin
(62)
seats
correctly
on
ball
bearing.
Replacing spring housing
Remove tonearm (30) from bearing frame (66) as described
above.
When
installing
notice
that
the
helical
spring
engages
in
the
cut-
outs of the bearing
(71). Mount tonearm
(30) again. Set bearing
play
as
described
below
using
threaded
pin
(65)
and
lock
nut
(61).
Adjusting the tonearm bearing
First
balance
tonearm
accurately.
Both
bearings
must
have
slight,
just
perceptable
play.
The
horizontal
tonearm
bearing
is
correctly
adjusted
when
at
anti-skating
setting
0.5
and
being
touched
it
slides
in
without
resistance.
The
vertical
tonearm
bearing
is
cor-
rectly
adjusted
when
it
swings
in
after
being
touched.
The
play
of
the
horizontal
tonearm
bearing
should
be
adjusted
with
thre-
aded
pin
(62),
the
play
of
the
vertical
tonearm
bearing
with
threaded
pin (65).
Anti-skating device
Adjustment of anti-skating force is carried out by means of
turning the knurled ring on the cover. According to adjustment
the asymmetrical cam disc guides the skating lever (134) from
the tonearm pivot point. The anti-skating force is transmitted to
the segment (124) by means of tension spring (136) and to the
tonearm.
Optimum adjustment is carried out at the works for styli with a
tip radius of 15 um (conical), 5/6 x 18/22 ит (elliptical) and CD
4 cartridges.
Any alteration can only be carried out with the aid of a Dual
skate-O-meter
and
a
test
record
and
should
only
be
done
by
an
authorized Dual service station.
Cue control
By moving lever (187) forward (Y.) lift cam (188) rotates. The
slide bar (168) connected to it transmits this movement to the
lift
pin
which
then
raises
the
tonearm.
As
a
result
the
cue
control
permits set down and lift off of the tonearm at any desired point
outside the shut-off range.
The slide bar (168) is released again by moving the cue control
lever (187) to the rear (X). As a result of the action of compres-
sion spring the lift pin is returned to neutral position and thus
lowers the tonearm. Lowering of the tonearm is damped by
silicone oil in the lift tube.
The set down speed can be varied by adjusting the pretension
of compression spring (lift plate 176). According to operation of
the
adjusting
ring
(82)
in
position
"4"
the
lowering
speed
is
slower, in position "444" it is faster.
Adjustment point
The lift height can be varied by turning adjusting screw (51). The
distance between record and stylus should be approximately 5 mm.
63
|—
62
74
66—
a
69
70
65-
e
=
тз
т
72
8t
82
83
ын
485
124-
94
138
Replacement of cue control plate
Replace cue control plate as follows:
1. Fix unit on repair jig and lock tonearm. Turn unit upside
down.
2. Remove securing disc (89). Detach main lever (167) and
bearing block (166).
3. Remove securing disc (89). Remove adjusting bar (168) and
rotary bearing (170) and swivel to motor.
4. Remove both filister head cap screws (97), remove cue control
plate complete (176).
Fitment takes place in reverse order. It should, however, be noted
that the pressure piece in the cue control plate (176) engages
correctly in adjusting ring (82) (varying the lowering speed.
Fig.9
е 9
Tonearm control
Automatic movement of the tonearm is indicated by the control
cams
on
the
inside
of
the
cam
wheel
(16)
on
rotating
through
3600.
The
control
elements
for
raising
and
lowering
are
the
control
lever
(167)
and
the
lift
pin,
for
horizontal
movement
of
the
tonearm
control
lever (167) with segment
(124).

The
automatic
set
down
point
is
designed
for
30
ст
and
17
ст
records
and
is
coupled
to
the
platter
speed
changeover.
Set
down
points
of
the
tonearm
are
determined
by
means
of
stop
of
spring
bolt of segment
(124) at the adjusting
bar (168). Limitation
of
the
horizontal
movement
of
the
tonearm
is
produced
by
stop
of
segment
on
adjusting
bar
(168)
which
is
lifted
off
only
during
set
down
by
the
main
lever
(167)
and
reaches
the
swivel
range
of
the
spring
bolt
on
the
segment.
On
completion
of
set
down
(lowe-
ring
of
the
tonearm
onto
the
record)
slide
bar
(168)
is
released
again
and
returns
to
its
neutral
position.
As
a
result,
this
is
out-
side
the
range
of
the
spring
bolt
so
that
unimpeded
horizontal
movement
of
the
tonearm
is
possible
for
playing.
Continuous automatic play
The
continuous
automatic
play
is
operated
by
turning
knob
(84)
to "00".
Switch
bracket
(179)
is actuated
by knob
(84).
Switch
rod
(180)
keeps
change
lever
(165)
in start
position.
After playing the record the tonearm returns automatically to
the
lead
in
groove
of
the
record.
This
process
will
be
repeated
until knob (84) is in position “17.
Adjustment point
Withdraw power plug. Remove turntable (3). Bring knob (84) to
position “оо”, Turn cam wheel to center position. The change-
over lever deflects the cam follower lever (U). By this means the
cam follower lever tip must be brought at least to the cam track
center. Adjustment by bending the switch rod (189).
Starting
Operation of push-button (59) “start” results in the following
functions:
a) The right hand pull magnet (142) operates cam followerlever
(165). At the same time the power switch (106) is operated
by the contact arm (127) coupled to the switching arm (78)
and the motor and turntable start to rotate.
b) This operation also releases start slide (39) which is drawn in
the direction of the cam wheel by means of the tension spring
(38). By this means the shut-off lever (8) on the cam wheel
(25) is brought into the range of the follower (M) (plate cone
22) and the cam wheel driven by this means.
Manual start
The detent (126) coupled to control arm (78) engages in the
square plate (125) when the tonearm is moved inward by hand
and retains the tonearm in this position. The power switch is
operated by the control arm and thus the motor and platter
start to rotate. After reaching the run-out groove of the played
record return of the tonearm and shut-off of the unit take place
automatically. If, on the other hand the tonearm is lifted off the
record
before playing
is
completed
and
moved
onto
the
rest
by
hand, the pin of segment (124) disengages the detent (126) so
that
the
control
arm
is
returned
to
its
starting
position.
As
a
result, the power switch shuts off the power supply.
Muting switch
To prevent disturbing noises during automatic operation of the
tonearm the unit is fitted with a muting switch. Control of the
switch springs for both channels is effected by the cam wheel.
With the unit in neutral state the short-circuit of the pick-up
leads is eliminated.
Adjustment point
In neutral position of the cam wheel a contact distance of ap-
proximately 0.5 mm should be present between contact springs
(F) and short-circuit strips (L). If necessary bend short-circuit
strips.
Spray contact springs with suitable means.
167 91 124 134
Fig. 11
22M 25 A 37 128 36
Stopping
When
push-button
(59)
"зор"
is
operated
the
changeover.lever
(165)
is
brought
into
stop
position
by
means
of
the
left
hand
pull
magnets
(142).
As
a
result
the
start
slide
is
released
which
is
drawn in the direction
of the cam wheel by means of tension
spring (38). By this means the shut-off
lever is brought
into the
range
of
the
follower
on
the
platter
pinion
(PR)
and
the
cam
wheel (25) is thus driven.

Shut-off operation
The
functions
of
end
switch-off
and
stop
switching
are
determi-
ned by the position
of the deflection
lever (U). The deflection
lever (U) is broughtto
stop position
bythe main lever (167) after
every start operation
(longer end of deflection
lever to cam wheel
center).
‚After
playing
of
a
record
shut-off
is
initiated
by
the
follower
(M)
of
the
platter
(3)
and
the
shut-off
lever
(А).
The
shut-off
bar
(128)
is
only
moved
synchronously
by
the
bolts
of
the
segment
(126)
in
the
shut-off
range.
In
the
shut-off
range
(records
116
to
122
mm
0)
the
shut-off
lever
(A)
is
guided
onto
the
follower
(Fig.
13
a)
by
the
shut-off
bar
(128).
The
follower
(M)
engages
shut-off
lever
(A).
By
this
means
cam
wheel
(25)
is
brought
out
of
zero
position
in
engage-
ment
with
pinion
of
platter
(Fig.
13
b).
The
main
lever
(167)
guides
the
tonearm
back
and
effects
tonearm
lowering
onto
the
support.
During
run-in
of
the
cam
wheel
into
zero
position
the
roller
(76)
of
the
switching
arm
(78)
run-in
to
the
cut-out
provided
on
the
cam wheel and operate
the power switch (106).
Adjustment points
Power fuse
After
removing
both
fastening
screws
and
detaching
power
secti-
on cover the fuse (102) on the power plate (101) can be replaced.
Tonearm set down point
The set down point of the tonearm can be altered with the ec-
centric bolt (172). If the stylus sets down too far in or out on
the record turn the eccentric bolt (172) correspondingly right or
left.
Shut-off point
The shut-off point (shut-off range records 116 — 122 mm ф) can
be
altered
with
the
eccentric
(E)
on
the
segment
(124).
Tonearm lift-off height
The tonearm lift-off height (during automatic operation) can be
altered with adjusting sleeve (177). Withdraw power plug. Un-
lock tonearm. Rotate cam wheel (25) out of zero position until
tonearm has reached its highest point.
The tonearm should be approximately 5 mm above the tonearm
support stop (Fig. 16). If necessary, turn adjusting sleeve (177)
to left or right.
Fig. 13
Fig. 14
Fig. 15
Fig. 16

Fig. 17
Fig. 18
Defect
Tonearm does not
set down or sets
down too quickly
after operating
cue control lever
(187).
Vertical tonearm
movement is in-
hibited
Platter does not
rotate after con-
nection of unit
and moving in of
tonearm
Tonearm does not
set down on the
edge of the record
Motor does not
switch off when
tonearm sets down
on rest.
Cause
Damping excessive
or too low by con-
tamination of the
silicone oil.
a) Lift pin (205)
jammed in guide
tube
Defective power
fuse (102)
Tonearm set down
point incorrectly
adjusted
Suppression са-
pacitor (110) in
power switch is defec-
tive (short-circuit).
Pull magnet “start/stop”
The stroke of the pull magnets can be altered with eccentric (Е 1).
The stroke should be set so that during “start” operation a play
of minimum 0.1 mm is present between the lap of the deflection
lever
(165)
and
the
start
slide
(39).
See
Fig.
11.
Pull magnet “lift”
The stroke of the pull magnets can be altered with eccentric
(E2). During operation of the pull magnet up to stop the lever
(187) should still just evidence perceptable play (min. 0.1 mm).
Safety regulations
Service
operations
on
electronic
units
may
only
be
carried
out
by
specialized
personnel.
The
unit
should
then
be
driven
by
an
isolating
transformer.
The
safety
regulations
in
accordance
with
VDE
0860
H
should
always
be
observed
during
repair.
In
addition,
construction
features
of
the
unit
should
not
be
altered
in
any
way
which
reduces
their
safety
e.g.
covers,
mecha-
nically
secured
leads,
creepage
and
error
distances
and
compo-
nents
must
correspond
to
the
original
spare
parts
list
and
be
cor-
rectly
fitted
again
(production
condition).
After
repair
it
must
be
ensured
that
all
conductive
components
which
can
be
touched
from
the
outside
do
not
carry
mains
voltage.
Remedy
Dismantle
cue
control
plate
(176).
Detach
control
stud
(175).
Remove
securing
disc
(178).
Unscrew
setting
sleeve
(177).
Remove
second
securing
disc.
Remove
lift
pin.
Clean
lift tube
and
lift pin.
Grease
lift pin
uniformly
with
“Wacker
silicone
oil AK
300
000".
Assemble
components
again.
See
above,
if
necessary
renew
cue
control
plate
(176).
Renew power fuse (102).
The tonearm set down point can be adjusted with eccentric pins
(172).
Renew
suppression
capacitor
in
power
switch.

Replacement Parts
Description Pos. |Part.-No. |Qty.| Description
1 |220213| 1 | Centering piece 57 | 247021] 1 | Switching plate
2
|
249 308
|
1
|
Turntable
mat
cpl.
260
101
|
1
|
Switching
plate
(for
metallic
fascia)
3
|
249309]
1
|
Platter
cpl.
58
|
235
150|
3
|
Compression
spring
4 [|245 695 | 1 | Rotary knob 59 | 247033| 3 | Push-button
5 [249310 | 1 | Speed control lever 249 474 | 3 | Push-button (for metallic fascia)
6 | 234 432] 2 | Spring suspension cpl. 60 | 249 325 | 1 | Weight, cpl.
234 433
|
1
|
Spring
suspension
cpl.
(TA
side
front)
61
|
246
884
|
2
|
Lock
nut
237227| 1 | Spring suspension cpl. (TA side rear) 62 | 230063| 1 | Threaded pin
7 | 230529] 4 | Threaded piece 63 | 260 222 | 1 | Frame cpl.
8 | 232842] 2 | Compression spring 64 | 232 551 | 1 | Compression spring
232 843
|
1
|
Compression
spring
(TA
side
front)
65
|
217438
|
1
|
Threaded
pin
236 711 | 1 | Compression spring (TA side rear) 66 | 260 224 | 1 | Bearing frame
9
|
200
723}
4
|
Rubber
damper
67
|
246
874
|
1
|
Pointer
10
|
200722|
4
|
Steel
cup
68
|
247
325
|
1
|
Securing
disc,
threaded
5.2/10
11 |260215| 1 | Mounting cpl. 69 | 247 136 | 1 | Rotary knob
12
|249312|
1
|
Вазе
CK
70,
walnut
70
|
246
882
|
1
|
Tensioning
screw,
long
249
314
|
1
|
Вазе
CK
70,
agate
black
71
|
260 226
|
1
|
Bearing
cpl.
249
315
|
1
|
Cover
CH
16
72
|
244
103
|
1
|
Hexagon
self-tapping
screw
2.9
x
6.5
13
|244889
|
4
|
Microswitch
73
|
244244
|
1
|
Disc
3.05/6/1.5
14 |247042| 2 | Potentiometer 74 | 249655 | 1 | Spring housing
15 |237782| 2 | Potentiometer nut 75 | 246 883 | 1 | Tension screw
16 | 246871| 1 | Seesaw switch 76 | 242 785 | 1 | Roller
249 477 | 1 | Seesaw switch (for metallic fascia) 77 | 242 768 | 1 | Extension bush
17а | 260217| 1 | Fascia cpl., agate black 78 | 247 301 | 1 | Switching агт
b | 260 978 | 1 | Fascia carrier cpl. (for metallic fascia) 79 | 242 167 1 | Tension spring
с | 260975 | 1 | Bracket fascia, metallic silver 80 | 234 838 | 1 | Adjusting wheel
260976 | 1 | Bracket fascia, metallic brown 81 | 247024| 1 | Disc
d | 249476 | 2 | Ring (for metallic fascia) 82 | 247023| 1 | Adjusting ring
е | 260979 | 1 | Identification plate (for metallic fascia) 83 | 260227 | 1 | Cover cpl.
+ | 249 473 | 3 | Ring (for metallic fascia) 84 | 245 685 | 1 | Rotary knob
18
|247191|
2
|
Rotary
knob
85
|
210
155
|
2
|
Toothed
disc
A32
19
|
242
191]
4
|
Threaded
pin
M3x3
86
|
210
586
|
9
|
Disc
32
87
|
200 444
|12
|
Spring
disc
21 247 039 | 2 | Fillister head self-tapping screw BZ 29 x6.5 88 | 242 677 | 1 | Fillister head screw M4x8
22
|242
192
|
1
|
Platter
cone
89
|
210
145
|
5
|
Securing
disc
23
23
245
663
|
1
|
Rotary
switch
90
|
210
146
|
7
|
Securing
disc
3.2
24 |246237| 1 | Distributor plate cpl. 91 | 210 147 | 3 | Securing disc 4
25 |246035| 1 | Cam wheel 92 | 210539 | З | Fillister head self-tapping screw В 2.9 х 13
26 |249319| 1 | Carrier plate ср!. 93 | 210 353 | 1 | Hexagon nut M2
249
320
|
1
|
Carrier
plate
1/2“
94
|
210 362
|
7
|
Hexagon
nut
M3
27 |249318| 1 | Tonearm head 95 | 210 366 | 1 | Hexagon nut м4
28
|237223|
1
|
Contact
plate
96
|
210469
|
8
|
Fillister
head
screw
M3x
3
29 |247836| 2 | Fillister head self-tapping screw В 2.9 х 19 97 | 210472| 5 | Fillister head screw M3x 4
30 |249332| 1 | Tonearm cpl. 98 | 210 486 | 4 | Fillister head screw M3x 8
31 |249323| 1 | Fastening TK 26 99 | 210516 | 2 | Fillister head screw M4x 8
32 |260218| 1 | Display unit cpl. 100 | 210517 | 4 | Fillister head screw M3x 30
33 |235851114 | LED, green LD 37/1 101 | 246 133 | 1 | Power plate cpl.
246 869 | 1 | LED, red LD 30/1 102 | 209 719 | 1 | Fuse insert Т 0.125 A/250 V
34
|
246
869]
1
|
Carrier
103
|
249
657
|
1
|
Power
transformer
ср!.
35
|260220|1
|
Scale
cpl.
104
|
249 658
|
1
|
Motor
mechanical
system
cpl.
260 977 | 1 | Scale cpl. (for metallic fascia) 105 | 247062| 1 | Cog
36 |247307| 1 | Brakelever 106 | 260 228 | 1 | Power switch cpl.
37
|226351|
1
|
Tension
spring
108
|
233012
|
1
|
Switching
plate
cpl.
38
|
233
710
1
|
Tension
spring
109
|
236 335
|
1
|
Slide
39 |242786|1 | Start slide 110 | 241883 | 1 | Capacitor 10 ДЕ
40
|
236 843
|
1
|
Hinge
en,
111
|
242822
|
1
|
HF
choke
47
uH
41 |210286| 2 | Cheese head self-tapping screw B 2.9x 9.5 112 | 230 148 | 1 | Switching angle
42
|231767|
2
|
Retainer
plate
113
|
219
200|
1
|
Snap
action
spring
43 |210668| 1 | Disc 5.3/10/1 114 | 239 732 | 1 | Tension spring
44 |231654| 1 | Hinge pin 115 | 247547 | 1 | Cover cpl.
45 | 234 145| 2 | Compression spring 116 | 210 498 | 1 | Fillister head screw M3x 28
46 |231656| 2 | Hinge cam 117 | 249 685 | 1 | Muting circuit cpl.
47 |231657| 1 | Hinge tongue 118 | 247515 | 1 | Threaded pin
48 |236092| 1 | Disc 62/10/1 119 | 247516 | 1 | Screening plate
49 |234837| 1 | Adjusting nut 120 | 242612 | 1 | Muting switch cpl.
50 | 247353| З | Chese head self-tapping screw B 2.9 x 13 121 | 242 182 | 1 | Contact arm
51 |242770| 1 | Adjusting screw 122 | 233 423 | 2 | Single-pole plug
52 |249324| 1 | Rest cpl. 123 | 247 303 | 1 | Switching bar
53 |239414| 3 | Transport lock cpl. 124 | 260 229 | 1 | Segment
54
|
247836|
2
|
Fillister
head
self-tapping
screwB
2.9
x
19
125
|
239915
|
1
|
Square
plate
55
|247040|
1
|
Microswitch
126
|
247
764
|
1
|
Рам!
241 646 | 1 | Capacitor 10 МЕ 127 | 247 308 | 1 | Contact arm
242822| 1 | НЕспоке 47 uH 128 | 247300| 1 | Shut-off bar
56 | 260 221 | 1 | Housing cpl. 129 | 209 357 | 1 | Ball $3.2

RS
@Q@
90
®©®®®
УЧИГ
У
|
A б
Nc
и.
ы
RE
Re
Wer
22
ый
wer,
,
446
à
Ó
/
ae
|
|
бе
Fig. 20

Fig. 21
ан
ва.
NS
Wa
мн
®®®
o

Pos.
|Part.-No.
(Оху.
Description
Pos.
|
Part.-No.
Or.
Description
130
|
232
104
|
1
Ball
seat
173
|
242
748
|
1
|
Adjusting
plate
131,
|
242
187
|
1
|
Switch
element
174
|
242
771
|
1
|
Rotary
plate
132
|
242
195
|
1
|
Switching
piece
175
|
216844
|
1
|
Control
stud
133
|
242298
|
1
|
Threaded
disc
176
|
260
231
|
1
|
Lift
plate
cpl.
134
|
244
331
|
1
|
Skating
lever
177
|
218 318
|
1
|
Adjusting
sleeve
135
|
239
903
|
1
|
Counter
bearing
178
|
210
143
|
1
|
Securing
disc
15
136
|
218
591
|
1
|
Tension
spring
179
|
247
288
|
1
|
Switching
angle
137 | 201 184 | 1 | Setting disc
180 | 247 287 | 1 | Switching bar
138 | 203475 | 1 | Countersunk screw
181 | 210549 | 1 | Disc
21
139 | 201 187 | 1 | Slide disc
182 | 237 381 | 1 | Leaf spring
141 | 260 230 | 1 | Magnet set-lift
183 | 260 323 | 1 | Magnet set start/stop
142 | 248 266 | 1 | Pull magnet
184 | 247 118 | 2 | Armature
143 | 247217| 1 | Агташге
185 | 260 233 | 1 | Solenoid protective circuit
146 | 245 661 | 1 | Stroboscope prism
186 | 237 543 | 1 | Rubber sleeve
147 | 245648 | 1 | Retainer piece
187 | 247509 | 1 | Lever
148 | 249 688 | 1 | Diode plate
188 | 247 289 | 1 | Stroke сат
245 235 | 3 | Luminescence
diode
1057 СА 190 | 214 602 | 2 | АМР соппестог
149 | 245699 | 1 | Stroboscope prism
191 | 209 436 | 3 | Flat connector sleeve
150 | 249689 | 1 | Motor electronic system-base plate
192 | 232996 | 1 | Power cable, Europe, cpl.
151 | 249690 | 1 | Motor electronic system-module
1
232995 | 1 | Power cable, America, cpl.
152 | 249691 | 1 | Motor electronic system-module
2
193 | 209424 | 1 | 5-pole plug
153 | 249 692 | 1 | Motor electronic system-module
3
194 | 207 303 | 1 | TA cable ср!.
154 | 245662| 4 | Rest
207 301 | 1 | TA cable cpl. with cynch plug
155 | 222038 | 6 | Plug
195 | 209 425 | 2 | Cynch plug, white
156 | 232 342 | 1 | Female multipoint connector ^ 2-pole
196 | 209 426 | 2 | Cynch plug, black
157 | 229 864 | 1 | Female multipoint connector
4-pole
197 | 246 079 | 1 | Mounting plate
158 | 226 514 | 1 | Female multipoint connector ^ Берое
198 | 237 548 | 2 | Cable conduit
159 | 210 283| 1 | Cheese head self-tapping screw 2.9 x 6.5 199 | 231079 | 1 | Cable clips, cpl.
160 | 260 213 | 1 Female multipoint connector
4-pole
201 | 247 313 | 1 | Compression spring
164 | 242 792 | 1 | Tension spring
202 | 209 353 | 1 | Ball
92
165
|
247 304
|
1
|
Changeover
lever
++»
|
248
166
|
1
|
Distance
roll
and
screws
for
TA-mounting
166 | 242 789 | 1 | Bearing block
+++ | 211 379 | 1 | Washer
2.1/5/0.5
167 | 246042 | 1 | Main lever
+++ | 245 646 | 1 | Filister head self-tapping screw B 2.2 x52
168 | 242 769 | 1 | Adjusting bar
(for TA-Removal prevention)
169 1544 8841 1 | Comprassion spring
эээ | 247471 | 1 | Operating instructions
170 | 237 498 | 1 | Rotary bearing
тйк 21305311
BERI ER
171 | 234 106 | 1 | Ball spring
9
172 | 242 751| 1 Eccentric pin

Lubricating instructions
All bearing and friction points of
the
unit
are
adequately
lubricated
at the factory. Replenishment of
oil
and
grease
is
only
necessary
after
approx.
2
years
of
normal
use as the most important bearing
points have sintered metal bushes.
The motor bearings have long-life
sintered metal bushings and thus
should not be lubricated. Bearing
points
and
friction
faces
should
be lubricated sparingly rather
than
generously.
When
using
dif-
ferent
lubricants,
chemical
de-
composition
can
often
take
place.
To
prevent
lubrication
failure,
we
recommend
using
the
original
lubricants
shown
below.
Wacker silicon oil
AK 300 000
BP super viscostatic
10 W/40
>>
Shell alvania No, 2
Fig. 22

CS Blockschaltbild EDS 920 Schéma bloc EDS 920 Block circuit diagram EDS 920
а Y Y
Generator
Digital/Analog
Wandler
Analog
аксар
200 pol. 4 Я i (Siebung)
en Verstärker u. Filt Impuls former Spannungsbegrenzer [Digital /analogue Koap o
Ein Amplifier + filter | вы Impuls shaper СЗ Voltage limiter convertor a ee i
Selten
Amplificateur
+
filtre
Formeur
d'impulsions
i
fn
Convertisseur
analogi-
CHE
da
inérateur Mémoire analogique
200 pol. а» (tamisagel
==! d ]
PLL у ES ї
||
Umschaltbarer Те Teiter Knackdámpfung
ille js! ғ e A
Quare оніое Changeover divider Я Volte comparitor Click damping
Diviseur commutable "n Amortissement des
Oscillateur à quartz
11:81
сет
Comerateur de tension
> crépitements
Impulsformer und
=
Überlaufrücksetzung
jen
Mono FF für Feinregler
Drabzahifainroglar
Mano
FF
for
fn
Dekoder
für
Vorimpuls
N
Гарні
кь
4,
кы,
rate
|
шы
оксочеиг
pour
Ен
|
vitessa
ПА
préimpulsion
Synchronisation
ge
démarrage
—
QPitch ein / aus
Q-Pitch on / off
Q-Pitch marche / arrêt
Netzteil (Trafo)
Power section
(transformer)
Bloc d'alimetation
(trafo)
Spannungs-Erzeugung
und Stabilisation
Voltage generation and
> | stabilization
Production де tension
et stabilisation
+25V
+15V
+ Бу
-5V
Hochlauf Synehroni- ||
Impedanz Wandier
prop.-diff.
Drehzahlumschali Teiler rücksetzlogik. Treiber ud Selbsthalt
tre D
Speed
changeover
Divider-reset
logic
=
Impuls
shaper
and
Sorokan
Sek
rarer,
euer
Commutatour
de
Logique
da
recul
driver
~
>
р
EA
hold
>»
g
ора.
3
vn
Sec?
аа
d'impulsion
||
|
хөвөнөрвио)
Le
Rot
ome
И
Leer
du
recul
écoulement
|
genres
timenda
Spannungs / Strom-
wandlung
Voltage-current
converter
Conversion de la
pps
Motor
Motor
Moteur
tension de courant
Komutierung und
| Motoransteuerung
Commutation and
motor actuation
Commutation ot dé-
marrage du moteur

Modul-Blockdiagram
l'asservissement
Module block diagram
Mutterplatte Base plate Platine de base
Schema
bloc
modulaire
Motoransteuerung
+ Vorverstärker
Motor actuation plus
pre-amplifier
Démarrage du moteur
+ preamplificateur
Spannungserzeugung
Stabilisation
Voltage generation
stabilization
Production de tension
vom Netztrafo
Ке
from
power
transformer
du transformateur de ri
| stabilisation
Stromver:
Current sı
Modut 1
Module 1
Module 1
Digital-Anatog-
Wandler
Digital-An:
convertor
Convertisseur analo-
aloque
gique-numérique
Control loop
Boucle d
Generator
Generator
Générateur
Blockschaltbild Anzeigeeinheit
von Drehzahlfeinregulierung
EDS 920
from speed fine regulation
EDS 920
du réglage de précision
EDS 920
>»
sorgung
upply
Alimentation en courant
Stroboskop LED
Stroboscope LED
Stroboscope LED
Modul
2
Modul
3
Module
2
Module
3
Module
2
Module
3
Referenzfrequenzar.
Eingangsverstärker
PLL
Pitch
Steueru
ng
nd
Input
ampl
Reference
frequency
generation
Solt-Wert
Pitch-control
te
Actual
value
Production
de
la fréquence
|]
Valeur
de
consigne
de
référence
Commande
Pitch
Ist
Wert
itch-Regler
Set
value
Valeur de consique
Block circuit diagram-Display unit
Logik zur Bestimmung
der Drehzahlabweichung
Logic for determination
of speed deviation
Logique pour la déter-
mination de l'écart de vitesse
T
Y
Bestimmung der Driftrichtung
déplacement
ation of drift direction
tion du sens de
indication
+ Affichage
Pitch-switch
Regulateur Pitch
Commutateur Pitch
Schéma bloc de l'unité d'affichage
Digital / Analog-Wandler
Digital-analogue converter
Convertisseur
analogique-
numérique
LED-Ansteuerschaltung
LED actuation switching
Montage de commande LED
Y
13-stufige LED-Skala
13-stage LED skale
Echelle graduée à 13 étages LED.

"^.
CS
714
Q
Service-Information
Service
Information
Instruction
de
service
Dual
EDS
920
Dual
Gebrüder
Steidinger
7742
St
Georgen/Schwarzwald

Funktionsbeschreibung
EDS
920
Bei der Motorelektronik des EDS 920 handelt es sich um eine
Drehzahlregelschaltung,
die
phasenstarr
(PLL)
die
Motordrehzahl
ао
die
heruntergeteilte
Frequenz
eines
Quarzoszillators
angleicht
“Ал Regelgröße dient dabei der Phasenwinkel der beiden zu ver
gleichenden
Freauenzen
(Generatorfrequenz,
Quarzieilerfre-
quenz). Zusätzlich beinhaltet die Schaltung eine Einrichtung zur
fenlosen
Änderung
der
Quarzirequenz
mittels
Potentiometer
Feinregulierung
+
8
%)
sowie
eine
Stroboskopschallung
mit
Leuchtdioden
als
Lichtemitter.
dia
ebenfalls
vom
Qu
өп wird.
Der
elektronische
Schaltungsaufbau
läßt
sich
in
folgende
Funk
tionsgruppen unterteilen:
1. Das Netzteil zur Erzeugung von vier Spannungen:
2.
Die
Quarzschaltung
zur
Erzeugung
der
Zeitreferenz,
sowie
"ie
Feinregulierung,
Drenzahlumschaltung,
Stroboskopeinrichti*
3
Eingangwerstärker zur Auf
Phasenvergleicher (PLL)
itung des Generatorsignals,
A.
Digital/Anatog
Wandler.
Potentiälspeicher
telektranischa
Siebung,
wird
auch
“Sample
an
Hold"
genannt)
5 Verstärker zur Motoransteuerung, Kommutierung
1. Netzteil
Der Netztransformator liefert seine Ausgangsspannung an den
Brückengleichrichter, der an dem Ladgelko C 9004 eine Spannung
von +24 V aufbaut
Diese unstabitisierte Spannung wird zur Speisung des Motors ba.
nutzt. Der integrierte Spannungsregier WA 78 M 15 IC 9001 leitet
aus ihr die stabilisierte 15 V Spannung ab. Eine einfache Parallel
Stabilisierung mit R 9002, D 9007 arzeugt davon die IC-Betriebs:
spannung von +5 V. Mit С 9003, C 9005. D 9005 und D 9006
wird eine negative Spannung erzeugt, die dann mit R 9001 und
©
9008
auf
—5
V
stabilisiert
wird.
Sie
dient
als
negative
OP-
Ver.
orgungsspannung (OP = Opsrationsverstärker). Die Spannungen
+18 V,45 М,-5 V sind kurzschlußfost
2. Quarzschaltung
Mit
dieser
Schaltung
wird
die
Referanztrequenz
erzeugt.
Der
mit
T
9301
aufgebaute
Quarzoszullator
schwingt
auf
4.508
MHz.
Er
steuert
die
erste
Teilerkette,
bestehend
aus
den
Zählern
IC
9301.
und
IC
9302,
an.
Diese
sind
für
die
Drehzahl
45
U/min
als"Teiler
durch
60"
geschaltet
(Drehzahtumschaltieitung
auf
707).
Die
Diodenmatrix
D
9301
bis
D
9304
ist
dabei
auder
Betrieb.
Durch
das
Umschalten
auf
die
Drehzahl
33
U/min
wird
über
Н
9306
die
Diodenmatrix
in
Betrieb
genommen
Die
Reset-Eingänge
der
IC
1
9301
und
IC
9302
sind
über
R
9308
negativ,
also
auf
logisch
L
vorgespannt.
Die
Anodenseiten
der
Dioden
sind
bei
45
U/min
ebenfalls
über
R
9306
und
В
9101
auf
LSignal.
Es
erfolgt
keine
Rücksetzung
und
die
Quarzfrequenz
wird
—
wie
bereits
erwähnt
—
durch
60
geteilt.
Beim
Umschalten
auf
33
U/min
wird
+5
V
über
В
9308
auf
die
Anoden
der
Dioden.
matrix
gegeben.
Solange
noch
einer
der
Bit-Ausgänge
(Pin
12.
Pin
11,
Pin
8)
auf
L-Signal
steht,
fließt
Strom
über
die
Diode
in
den
Ausgang
des
IC.
Es
kann
auf
der
Anodenseite
kein
H-Signal
entstehen.
H-Signal
liegt
an
allen
drei
Ausgängen
das
erste
Mal
gemeinsam
an,
wenn
der
Teiler
von
BO-fach
auf
Bl-fach
springt.
Dieses
bildet
ein
Н
Signal
an
den
Anoden
der
Dioden
und
es
erfolgt
“Reset”
über
den
Transistor
T
9302
des
Teilers
auf
0.
Es
ist
ein
Teilungs-
Vor.
haltnis
von
81
:
1
entstanden,
Mit
dam
Transistor
T
9302
kann
diese
Teilerkette
asynchron
auf
"0"
gesetzt
werden
(wird
zur
Feinregulierung
benötigt).
Die
Ausgangs
Frequenz
dieser
Stufe,
die jetzt
76 800
kHz
(bei
45 U/min]
bzw.
56.8
kH2
(bei
33 U/min)
beträgt,
wird
nun
in neun
Stufen
(1 durch
29)
mit
IC 9303
auf
111,1
Hz
heruntergestellt.
C 9310
und
В 9310
leiten
daraus
einen
Impuls
von
0,7
ms
Länge
ab,
der über
T 9303
die
Konstant-
stromquelle
T 9304
zur
Speisung
der
Leuchtdioden
ansteuert.
Parallel
dazu
ist der
Teiler
IC 9304
angeschlassen,
der
mit
ebenfalls
9 Bit
den
Drehzahlsoltwert
für den Phasenvergleich
erzeugt.
Ist die
Feinregulierung
ausgeschaltet
(Q Pitch
aus)
oder
der
Feinregler
in
Mittensteilung,
зо beträgt
die Ausgangsfrequenz
genau
111,1
Hz
Die
Stroboskopeinrichtung
erzeugt
dadurch
ein
stehendes
Bild.
Mit D 9205 bis D 9307 und Я 9309 wird aus dem Teiler IC 9304
ein Vorimpuls gewonnen, der 8 25 % vor dem zeitlichen Eintref
fen des Ausgangssignals einsetzt IsicheSkizze Vorimpulsdecoder)
Im
Ruhezustand
wird
die
Basis
des
T
9305
über
А
9314
positiv,
der Transistor leitet, Die Kollektor Spannung ist hierdurch klein.
was
einem
L.Signal
an
Pin
6
von
G
52
entspricht.
Der
Vorimpuls
bringt
ein
logisch
H
Signal
an
Pin
5,
was
ein
L
Signal
am
Ausgang
zur Folge hat. Differenziert über C 9311 sperrt dieser Impuls
T 9305, wodurch die Kollektor Spannung sprunghaft ansteigt
und als H.Signal an Pin 8 anliegt Beide Gatter-Eingänge sind so.
mit
H
(Highl
und
der
Ausgang
bleibt
als
Folge
L
(Low)
Der
Ausgangs-Impuls des Monoflops dauert je nach Stellung des Fein
reglers БО ps bis 1,1 ms. Die KollektorSpannung von T 9305
wird wieder klein und dieser L-Impuls, welcher die Rücktlanke
дез Monoimpulses darstellt. gelangt an Pin 6 von G 52 und außer
dem differenziert an Pin 8 des Nand Gatters б 62, Ein L-Signal
am Gatter-Eingang hat ein H-Signal am Ausgang zur Folge. Der
Teiler
IC
9304
und
über
T
9302
wird
IC
9301
und
IC
9302
rückgesetzt. Der Záhlvorgang startet erneut
Der Zeitpunkt des Rücksetzimpulses, also сіе Stellung dos Fein
reglers ist ausschlaggebend. ob die Taller Ausgangstrequenz größer
oder
kleiner
als
die
"Normatfrequenz”
ist,
(Siehe
Impui
Diagram!
Feinreguliorung aus
Bei
ausgeschalteter
Pitch-Control
wird
der
Pin
6
des
G
62
aut
logisch
H
gehalten.
Im
Spielbetrieb
ist
auch
der
Pin
5
auf
H-Signal,
das
am
Ausgang
des
Nand-Gatters
ein
L:Signal
bewirkt.
Eine
Rücksetzung
der
Teiler
ist nicht
möglich.
Mit den Gattern G 61, G 63, G 64 wird während des Hochlaufens
des Motors die Quarzteilerfrequenz zur Generator-Frequenz syn
chronisiert, um beim Erreichen der Nenndrehzahl ein sauberes
Einrasten des PLL sicherzustellen. Dieser Vorgang wird abschlie
Bend beschrieben.
3. Eingangsverstärker, PLL
Der
Frequenzgenerator
der
starr
mit
dem
Motor
gekoppelt
ist
liefert
pro
Umdrehung
200
Perioden
einer
Sinus
Wechselspannung
von
etwa
7
mV
effektiv.
Der
Elko
C
9201
schließt
höheı
frequen:
te
Anteile
(Störungen)
kurz,
IC
9201
a
verstärkt
das
Signal
auf
einige
Volt
und
steuert
den
als
Schmitt-Trigger
geschalteren
IC
9201
b
an.
Der
Hochpa®,
bestehend
aus
C
9202
und
R
9203
hält
dabei
Schwebungen
des
Genoratorsignals
von
IC
9201
b
fern.
Die
von
IC
9201
b
erzeugten
Rechteck
signale
werden
mit
9201
und
D
9202
auf
--0,7
V
und
+5,7
V
begrenzt
(Ausgangsspannung
des
OP
ist
wesentlich
größer).
Dieses
Logiksignal
liegt
an
einem
der
beiden
Eingänge
des
PLL
und
präsentiert
dort
den
Drehzahl
Istwert
zur
Phasenvergleichung.
Die
diskret
aufgebaute
PLL:
Schaltung
hat
zwei
Eingänge,
an
denen
die
zu
vergleichenden
Frequenzen
anstehen,
Es
werden
nun
digital
die
Impulse
derart
verarbeitet,
daß
bei
Frequenzgleichheit
je
nach
Phasenbeziehung
zueinander
an
einem
oder
anderem
Ausgang
ein
Signal
ansteht,
das
jeweils
den
Betrag
der
Phosenverschiebung
beinhaltet.
Der
Ausgang
an
Punkt
9
wird
weiter
zur
Motorsteuerung
herange-
zogen,
der
Ausgang
an
Punkt
8
dient
zur
Erkennung
eines
Übor.
schwingers.
um
die
Hochlaufsynchronisierung
auszuschalten
und
somit
den
PLL
exakt
bai
Nenndrehzahl
einrasten
zu
lassen.
Die
Arbeitsweise
der
PLL-Schaltung
ist
aus
dem
Impulsdiagran
sichtbar.
4. Digital-Analog Wandler
Die
aus
der
PLL
Schaltung
gewonnenen
Impulse
beinhalten
in
ihrem
Impuls
Pausenverhältnis
die
Phasenlage
der
Quarzfrequenz
zur
Generator-
also
zur
Istfrequenz.
Diese
Information
wird
auf
den
Digital-Analog
Wandler
gegeben.
Während
der
L
Phase
des
Signals
wird
der
Transistor'T
9101
leitend
und
lädt
C
9101
auf.
Zur
gleichen
Zeit
wird
der
Analog.
Schalter
G
23
über
R
9104
geöffnet,
Ein
H
Signal
sperrt
9101,
während
G
23
geschlossen
wird.
Hierdurch
gelangt
die
Ladung
von
С
9101
auf
den
Speicher-Kondensator
C
9102
(Sample
an
Hold)
Der
nachgeschaltete
sehr
hochohmiga
Impedanzwandler
belastet
diese
Signalquelle
nicht
Um
ständig
am
Kondensator
C9101
die
augenblickliche
Drehzahl.
abweichung
erkennen
zu
können,
wird
dieser
zu
Beginn
jedes
Ladevorganges
über
T
9102
entladen.
T
9102
wird
leitend
durch
einen
positiven
Impuls,
der
durch
C
9306
3
pis
verzögert
über
das
Nand.Gatter
G
53
erzeugt
wird,
Dieser
entsteht
wiederum
durch
die
negative
Flanke
der
heruntergsteilten
Quarzfrenuenz
an
Pin
12
von
I
9304,
welche
differenziert
über
C
9305
auf
Pin
8
von
G
53
anliegt
Beim Überschwingen des Motors ist der QAusgang Pin 1 der