- 12 -
- 15 -
6.3.4 Over-current short circuit protection: An over-current resistor sampling triode is
parallel connected to the output load resistor of the channels L&R respectively. The
channel L's sampling tube is V426 and its load resistor is R424 and R425. Another three
channel power amplification IC have over-current protection function. When over-current
fault occurs to the L or R channel, the potential between R424 and R425 will increase
sharply. When it supersedes 0.7V, V426 will get conducted. So will v430. Finally, the
relay is switched off and the protection circuit is getting started.
Over-current
Sampling triode
connected to
every channel
Channel
L s is
V426
Collector s
voltage
decreases
V430
Conducted
R424
¡¢
R425
over-current.
Potential
increases.
V426
conducted
Relay swit ched
off.
Protection
started up.
¢ò
.
IN
S
T
R
U
C
T
IO
N
S
T
O
T
H
E
C
IR
C
U
IT
S
1
.T
H
E
F
R
O
N
T
C
O
N
T
R
O
L
P
A
N
E
L
M
A
IN
P
A
R
T
S
L
IS
T
O
F
T
H
E
F
R
O
N
T
C
O
N
T
R
O
L
P
A
N
E
L
B
O
A
R
D
NO. DESCRIPTION SPECIFICATIONS/PART NUMBER
LOCATION SPECIFICATIONS
1
CARBON-FILM
RESISTOR
1/6W100
¦ ¸
±5% SHAPED 7.5
R905,R906,R910,R907
2
CARBON-FILM
RESISTOR
1/6W560
¦ ¸
±5% SHAPED 7.5
R959
3
CARBON-FILM
RESISTOR
1/6W1K±5% SHAPED 7.5
R919,R921,R924,R926,R967,R952,R923,R928
4
CARBON-FILM
RESISTOR
1/6W1.5K±5% SHAPED 7.5
R933,R951
5
CARBON-FILM
RESISTOR
1/6W4.7K±5% SHAPED 7.5
R916,R970,R971,R972,R938,R961
6
CARBON-FILM
RESISTOR
1/6W10K±5% SHAPED 7.5
R955,R956,R960,R965,R930,R931,R943,R947,R949,
R950,R953,R968,R901~R904,R911~R914,R980
7
CARBON-FILM
RESISTOR
1/6W12K ±5% SHAPED 7.5
R958,R957,R964
8
CARBON-FILM
RESISTOR
1/6W22K±5% SHAPED 7.5
R969,R941,R935
9
CARBON-FILM
RESISTOR
1/6W47K±5% SHAPED 7.5
R920,R922,R925,R927,R929
10
CARBON-FILM
RESISTOR
1/6W100K±5% SHAPED 7.5
R932,R963
11
CARBON-FILM
RESISTOR
1/6W15K±5% SHAPED 7.5
R954,R966,R946,R976,R977,R978,R940
12
CARBON-FILM
RESISTOR
1/6W3.3K±5% SHAPED 7.5
R948
13
CARBON-FILM
RESISTOR
1/6W220K±5% SHAPED 7.5
R962
14
CARBON-FILM
RESISTOR
1/6W30K±5% SHAPED 7.5
R936,R942
15
CARBON-FILM
RESISTOR
1/6W8.2K±5% SHAPED 7.5
R937,R939,R934
16
CARBON-FILM
RESISTOR
1/2W100
¦ ¸
±5% SHAPED 12.5
R915
CARBON-FILM
RESISTOR
1/6W56K±5% SHAPED 7.5
R908
17
CARBON-FILM
RESISTOR
1/6W47
¦ ¸
±5% SHAPED 7.5
R909
18
CARBON-FILM
RESISTOR
1/6W470K±5
£ ¥
SHAPED 7.5
R944
19
Rotating
Potentiometer
A115NOED-H1B503-007
RP903,RP904
20
Rotating
Potentiometer
R1111NOA-V1C503FK00-01
RP901,RP902
21
Digital
Potentiometer
E1611A3A-V1FG05-01 WITH
SPACER
RP905
COMPONENTS LIST OF THE FRONT PANEL
3
2
1
8
4
N
9
0
3
A
N
J
M
4
5
5
8
5
6
7
N
9
0
3
B
N
J
M
4
5
5
8
3
2
1
8
4
N
9
0
4
A
N
J
M
4
5
5
8
R
9
2
1
1
k
R
9
2
6
1
k
R
9
2
2
4
7
k
R
9
3
4
8
.2
k
C
9
2
1
8
2
P
C
9
4
2
4
.7
u
/1
6
V
R
9
2
7
4
7
k
-1
2
V
R
P
9
0
4
B
5
0
k
C
9
3
2
4
.7
u
/1
6
V
-1
2
V
+
1
2
V
C
9
3
0
5
6
2
R
9
4
8
3
.3
k
R
9
7
6
1
5
K
C
9
2
8
4
.7
u
/1
6
V
5
6
7
N
9
0
4
B
N
J
M
4
5
5
8
R
9
3
9
8
.2
k
C
9
2
2
1
2
3
R
9
4
1
2
2
k
R
9
4
2
3
0
k
C
9
2
3
4
7
1
+
1
2
V
R
9
6
8
1
0
k
R
9
5
3
1
0
k
C
9
2
4
1
0
4
C
9
1
6
8
2
P
C
9
1
8 8
2
P
R
9
3
2
1
0
0
K
R
6
3
5
2
2
k
R
9
3
3
1
.5
K
R
9
6
0
1
0
K
R
9
4
3
1
0
k
R
9
4
0
1
5
k
R
9
4
4
4
7
0
k
C
9
2
5 8
2
P
R
9
3
6
3
0
k
R
9
3
8 4
.7
k
R
9
4
7
1
0
k
C
9
2
7
4
.7
u
/1
6
V
C
9
4
3
4
.7
u
/1
6
V
V
9
0
2
9
0
1
4
R
9
6
4
1
2
k
R
9
6
5
1
0
k
R
9
6
6
1
5
k
C
9
4
4
1
0
u
/1
6
V
R
9
6
2
2
2
0
k
R
9
6
3
1
0
0
k
C
9
4
6
4
.7
u
/1
6
V
+
1
2
V
R
9
3
7
8
.2
k
C
9
1
9
4
.7
u
/1
6
V
V
9
0
1
9
0
1
4
R
9
2
9
4
7
k
R
9
3
0
1
0
k
R
9
3
1
1
0
k
C
9
2
0
4
.7
u
/1
6
V
+
1
2
V
-1
2
V
C
9
4
5
4
7
0
u
/1
6
V
V
D
9
0
9
1
N
4
1
4
8
R
9
6
7
1
k
R
9
6
1
4
.7
k
R
9
4
9
1
0
k
C
9
3
3
8
2
3
R
9
5
4
1
5
K
C
9
3
5
5
6
2
C
9
3
7
1
0
4
C
9
3
1
1
0
3
C
9
2
9
5
6
1
R
9
5
5
1
0
K
R
P
9
0
3
B
5
0
k
R
9
5
1
1
k
R
9
5
6
1
0
K
C
9
3
9
4
7
u
/1
6
V
R
9
5
8
1
2
k
C
9
3
8
1
0
4
R
9
5
0
1
0
k
C
9
3
6
8
2
3
V
C
C
1
R
E
F
2
A
G
3
D
G
4
C
L
K
5
V
C
O
6
C
C
1
7
C
C
0
8
P
1
-O
9
P
1
-I
1
0
P
2
-I
1
1
P
2
-O
1
2
F
2
-I
1
3
F
2
-O
1
4
F
1
-O
1
5
F
1
-I
1
6
N
9
0
5
P
T
2
3
9
9
R
9
5
7
1
2
k
C
9
4
0
1
0
4
C
9
3
4
5
6
1
R
9
2
8
1
k
R
9
2
3
1
k
R
9
2
4
1
k
R
9
1
9
1
k
R
P
9
0
2
C
5
0
K
M
IC
1
M
IC
2
F
ro
m
M
I
B
o
a
rd
R
P
9
0
1
C
5
0
K
G
N
D
K
-M
C
9
1
5
1
0
u
/1
6
V
C
9
1
7
1
0
u
/1
6
V
R
9
2
0
4
7
k
R
9
2
5
4
7
k
C
9
4
1
4
7
u
/1
6
V
V
D
9
1
0
5
.6
V
R
9
5
9
5
6
0
+
1
2
V
R
9
5
2
1
k
R
9
4
6
1
5
k
C
9
2
6
4
.7
u
/1
6
V
R
9
6
9
2
2
k
+
1
2
V
-1
2
V
M
IC
T
o
A
M
P
B
o
a
rd
1
2
3
4
5
6
7
8
X
P
5
8
P
IN
D
+
5
V
C
9
4
7
4
7
u
/1
6
V
C
9
4
8
4
7
u
/1
6
V
1
2
3
4
X
P
6
4
P
IN
V
9
0
4
2
N
5
5
5
1
R
9
8
0
1
0
k
C
9
5
8
4
.7
u
/1
6
V
C
9
5
1
1
0
3
C
9
5
2
1
0
3
C
9
5
3
4
7
u
/1
6
V
C
9
5
4
4
7
u
/1
6
V
+
1
2
V
+
1
2
V
-1
2
V
-1
2
V
C
9
5
5
1
0
4
C
9
5
6
1
0
4
R
9
7
7
1
5
k
R
9
7
8
1
5
k