Sharp GF-9090H User Manual

Accordingly, the potential of the C407 is permitted to be
stabilized from zero (0) volt to +12 volts. When the
potential exceeds VBE, the Q404 is turned “OFF”. Then
the Q404 is turned “ON”’, and +B is supplied to the base
of Q405 through the R414, turning “ON” the Q405.
Then, an end of the plunger is grounded and +12V is
applied to the plunger, which, in turn, is actuated. When
the Q404 is turned “OFF”, the Q405 is also turned “OFF”’,
cutting off the potential to the plunger. When the plunger
is put in action, the APSS lockplate is stretched out to
release the FWD-APSS key. Consequently, the FWD-APSS
switch (SW501) is turned “OFF” and the pinch roller is
pressed hard against the flywheel shaft. Moreover, the
fastforwarding gear is disengaged from the gear of the
takeup turntable, setting the unit in normal playback
mode again. As the FWD-APSS switch (SW501) is turned
“OFF”, the light emitting diodes of D513, D512 and
D511 stops flickering and the APSS limiter circuit is
made inactive. Further, the muting circuit of Q302 and
Q305 also stops its function.
In the meantime, when the REV-APSS key is depressed
the fast-forwarding gear meshes with the gear of supply
turntable and the REV-APSS switch (SW502) is turned
“ON” to set the tape in rewind mode, permitting the
light emitting diodes of D511, D512 and D513 to flicker.
The successive function is just as in the case of FWD-APSS
behavior.
This ends the explanation of the APSS performance.
However, that the APSS may malfunction when either
one of following recordings is played back, but, remember,
this is not a trouble.
1.
2:
a
A prolonged portion of pianissimo in music.
A blank portion in the midst of music (more than 3 seconds
when measured in playback).
* In cases 1 & 2 the FWD-APSS or REV-APSS key,
if depressed, resets itself and regular playback mode
is resumed.
. A too short interval between programs (about 1 second
when measured in playback).
. Anoisy hum or buzz recorded in a blank portion.
* In cases 3 & 4 the condition doesn’t allow the APSS
circuit to work easily, and the blank portion couldn’t
be detected.
. FWD-APSS key depressed within 10 seconds (as measured
in playback) from the end of a preceding selection.
. REV-APSS key depressed within 10 seconds (as meas-
ured in playback) from the beginning of a selection.
* In cases 5 & 6 the tape runs 10 or 30 times as fast as in
playback mode if the FWD-APSS or REV-APSS key is
depressed, therefore the tape skips a blank portion
while the key is being depressed.
APSS MIXER MUTING CIRCUIT
[—————~1 APSS IND. CIRCUIT
I+12V
f——> PLUNGER ({SOLSOI)
R401 sepa
15K
c4or
022(Z) \C -40]
RH-IXO408AFZZ
Po R40:
age | ex | Binh
2
47K
ve ©.
+
C406 04
3.3/50V(M
OMP
A
02
)
© GROUND
Q401 2SA495(Y) Q402,Q403 2SC372Y(Y) Q404 2SA495(Y)
SWITCHING Q405 2SD468(C)
PLUNGER DRIV.
Figure 14 APSS DETECTION CIRCUIT
[mee APSS SW
sw501 |FwD. APSS Sw
(REV aPSS SW)
ON
(Sw502)| (REV. APSS_ SW)
OFF.
Voss a _ BLANK <.
MUSIC A SECTION MUSK B
H
EQUALIZER AMP.
(Q201- 0204) | ]
APSS MIXER(Q208) | \ |
' !
!
| |
APSS PRE
AMP (IC 401)
=e | TIME CONSTANT
| pT (R408 ,c406)
TERMINAL os
| VeE
VOLTAGE | | we :
nee
9401 =
(282L econ} 1 Ve
| |
| rt
i
( 9402 ) I
COLLECTOR |
ON |
ne | |
Sees
OFF |
(2403 ) :
COLLECTOR |
= fete SS
fe
(sate Laon)
i i
! it
1 =a
! if
0403 (Vee)
! i
|
|
\ 404(0N)}
|
! OFF
T tot
i
I
!
t
]
| OFF
i '
I !
¥ i
TAPE Hi 1
! NORMAL SPEED
SPEED | | x 10~ 30 are
: I
Refer to Figures 10,1!
( 0404 )
COLL ECTOR
PLUNGER
KE
APSS IND.
LAMP (LEO)
Figure 715 APSS MOVEMENT PRINCIPLE

Sharp GF-9090H Specifications

General

Brand	Sharp
Model	GF-9090H
Category	Stereo System
Language	English