RCA SelectaVision VideoDisc SFT 100 Service Data page 8

СЕО-1
ELECTRONIC/MECHANICAL SYSTEMS DESCRIPTION
(continued)
signals develops an error signal which is applied to the
armstretcher circuit. This circuit operates a solenoid (located on
the pickup arm assembly) moving the stylus (laterally with
respect to the disc) to maintain a constant disc to stylus velocity.
The armstretcher circuit output is also coupled to the converter
oscillator (5.11 MHz VCXO) in order to maintain phase lock be-
tween the upconverted 3.58 MHz color signal and the crystal con-
trolled 3.58-MHz reference oscillator.
AC and DC Power Supplies
All the electronic circuits in the SFT100 VideoDisc player are isol-
ated from the power line, i.e. cold ground. Referring to Figure 1-3.
the AC input is applied to the PW AC IN circuit board. Intitial pro-
tection is provided by a 1-Amp fuse (F1). The AC power switch,
52, is controlled by the function lever. AC power is applied to
power transformer, T1, when the function switch is in the "Load"
or "Play" position. Power transformer, T1, is protected by F2, а
1/4-Атр fuse.
m
ЕЯ READOUT
wDiCATORS
PW200
RESONATOR PW БОО
PW900
PREAMP
CONTROL PANEL
CONTROL BOARD
The secondary of T1 contains two windings — one developing
nine volts RMS utilized to generate a 5-volt regulated supply, the
other developing 18 volts RMS providing a 22-volt unregulated
DC supply.
AC power from 82 is also applied to AC Play Switch, S4. The AC
play switch is controlled by the function lever and is closed only
in the PLAY position. The AC play switch is open in the "load"
position.
AC Play switch, 54, connects to the AC Spine Sense switch, S8, in
series with the turntable motor. The AC spine sense switch is ac-
tivated only with a spine and disc in the player. The closing of AC
power switch (S2), AC play switch (S4), and AC spine sense
switch (S8) applies power to the turntable motor (i.e. all three
Switches must be activated before the turntable motor will func-
tion).
РУ/7ОО ADAPTIVE NLAC AND
NOISE CORING BOARD
FUNCTION
SWITCHES
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Н
П i
р
1
4 i
4
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E uc | ае |
нек om] моо |
Ee «un
| anu output
2
PW 3000
SIGNAL PROCESSING
за | интлван.
ы мн 1
ss
D
но Тон
тен Le о
set Ў шее
ак
М
тори ас
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ше 64022224
aso з мо!
[з сек сотвут
m VERTICAL GETAL
'OUTPUT
|
сой
MINT/ORN.
Іза (SoUELCH:
(ARM STRETCHER) (RADIUS SENSE)
ASG ASW ап аз?
TURNTABLE
MOTOR
Ag SPINE,
SENSE,
Fig. 1-3. — Overall System Wiring Diagram