XV-DV830
103
5
7
8
5
7
8
C
D
F
A
B
E
4
When DC is generated at the output because of
a failure in the AMP system, etc.
5
When abnormally high temperature is detected
by the thermistor
R3357
(R3625)
(R3457)
18k
R3358
(R3626)
(R3458)
10k
R3603
10k
Front L ch
(SW, SL)
+5V
C3632
100/10
Q3605
Q111
2SC4081
R113
220
IC81
NJM7805FA
R112
1k
TH111
NCP18WF104J03RB
R111
1k
Q3604
Q3606
Q3607
B
C
E
+
XPROTECT
to
XPROTECT
POWER Assy
[Sub Woofer side]
[Sub Woofer side]
[Sub Woofer side]
D
R108
27k
VD+5
VD+5
6CH AMP
Assy
C
6CH AMP
Assy
C
Front R ch
(C, SR)
• In Normal mode, both Q3605 and Q3604 are off.
(1) When positive (+) DC voltage is generated at the SP
terminal
When positive (+) DC voltage is generated at the L or R channel,
and VB of Q3605 becomes higher than that at the operation point,
Q3606 (E, C, B) is turned on, and the level of XPROTECT
becomes low.
→
The microcomputer detects the XPROTECT level and shuts
the power to the unit off.
(2) When negative (-) DC voltage was generated at the SP
terminal
Q3604 is turned on, and XPROTECT is activated.
5
-1 IC81 abnormal temperature detection circuit
A
The voltage at Point
A
becomes the divided voltage of TH111
and R111//R112 (combined resistance of parallel-connected
resistors R111 and R112.) In Normal mode, the resistance at
TH111 is much higher than R111//R112, and Q111 is off. (Note
that the resistance at TH111 becomes lower as the temperature
increases.) If the solder temperature at IC81 increases abnormally,
the temperature at TH111 (thermistor) mounted closest to the land
of IC81 increases accordingly, and the resistance at TH111
decreases.
When the temperature at TH111 reaches 90-110_C (varying
according to conditions,) the voltage at Point (A) becomes high
enough to turn Q111 on, and the level of the XPROTECT line
becomes low. The microcomputer detects the XPROTECT level
and shuts the power to the unit off.
www. xiaoyu163. com
QQ 376315150
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TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299
