RCA SelectaVision VideoDisc SFT 100 Service Data page 62

CED-1 Addendum-2
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 bet-
ween 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 аге isol-
ated from the power line, t.e. cold ground. Referring to Figure 1-3,
the AC input is applied to the PW АС IN circuit board. Intitial pro-
tection is provided by a 1-Amp fuse (F1). The AC power switch, S2,
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, a 1/4-
Amp fuse.
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. í
AC power from S2 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" and
"OFF" positions.
AC Play switch, 54, connects to the AC Spine Sense switch, S8, п
series with the turntable motor. The AC spine sense switch is acti-
vated only with a spine and disc in the player. The closing of AC
power switch (52), 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
function).
PW'7OO ADAPTIVE NLAC AND
NOISE CORING BOARD
PW 3000
SIGNAL PROCESSING
змо!
9 STYLUS LIFTER тыкка.
ады ут
эли STRETCHER
м n
ШЕ Ж
1 к
Май ыма isv
з! НИСКУ ву
Ж еле Tu шоо wur
ме. Ган зе
t
з
з.» U зо (конен).
тн о
UAM STRETCHER) (RADIUS SENSE)
hs "ыйы аю Hw эй мї
e м
Бад о ү
anu н
servo abo
peated ADIGE BENSE
TURNTASLE
MOTOR
33 CLOSED N 37 TERM 2 CLOSED
34 CLOSED IN PLAY за OPEN WHEN KO SPINE
53 NORMALLY OPEN 89 CLOSED N LOAD
Fig. 1-3. — Overall System Wiring Diagram
18A