XW-HTP550
40
1
2
3
4
1
2
3
4
C
D
F
A
B
E
7.1.5 PROTECTION CIRCUIT
DC detection circuit
SP PROTECT is set to "H"
Q3453 turns on, next Q3454 turns off.
In connection with it, the power supply (+VP) to IC3302 POWER IC
is lost in RY3301 relay turning off.
Therefore, an unusual state (DC output state) is canceled.
In addition, if an unusual state is canceled, since RY3301 relay turns on,
DC detection of it will be carried out again, SP PROTECT will be set to "H",
and RY3301 will repeat ON/OFF.
Cautions: Since RY3301 relay repeats ON/OFF, a check on a feeling of hearing
can be taken at the time of abnormalities.
Since a relay repeats ON/OFF, be careful of +VP voltage at the time of diagnosis.
PROTECT Operation Description
A
MAIN ASSY
(AWU8261)
E
C
B
B
4
3
E
C
B
E
B
C
E E
C C
B
1
2
3
1
2
5
4
13
11
14
12
5
7
8
9
2
6
10
3
4
1
Q3454
R3463
C3464
C3463
D3452
D
3451
RY3301
R3464
R3456
Q3455
Q3451
D3453
C3462
R3459
R3465
Q3453
R3461
R3460
R3462
R3458
C3451
R3455
R3457
Q3452
R3451
R3452
R3453
R3454
C3311
C3310
CN3401
RY3301
C3312
C3313
IC3302
220/6.3
2SC2412K(QR)
56k
-TS
47/25
STBY
ASR7019
10k
2SD1858X(QR)
VPRE9
2SA1576A
GNDD
UDZS9R1(B)
10k
10k
220/6.3
220
2SC4081
220
220
3.9k
STBY
VREF5
VD+9
NP
100/10
4.7k
10k
2SA1576A
0.01
100/25
GNDP
GNDP
B5P-VH
4.7k
4.7k
4.7k
4.7k
ASR7019
VP
+B
+B
-TS
10/50
-TS
47/25
LA4663
(1/2)
(QR)
SP PROTECT
(QR)
(QR)
(2/2)
AL-TS
L in
SR+ (L+)
SL- (R-)
SR- (L-)
SL+ (R+)
NC
SL+ (R+)
SL- (R-)
SR- (L-)
SR+ (L+)
GNDP
R- OUT
R+ OUT
L- OUT
STANDBY
MUTE
MUTE
GNDP
VCC2
VCC1
GNDA
R IN
L IN
L+ OUT
RF
IC3302
LA4663
TO SPEAKER
