Cambridge Audio Azur 540A V2.0 Amplifier
AP17649/5 Input PCB Schematic (Protection Circuitry)
+5Volts
R66
1k
For 1mA
R64
10k
R67
100R
R65
2R7
DGND
3
2
1
8
4
U8:A
LM393
D7
1N4148
+5V
Speaker short circuit tester
R69
4k7
(Open Collector Output)
Senses a DC resistance of 2 ohms or less
D6
1N4004
PIC VI/Short
C43
100N 50V X7R
Speaker Test
DGN
D
+5V
SW1:B
SW-DPDT
TAPE
SPEAKER B SWITCHING (for relay)
Speaker Test
Speaker A Relay
Unreg for Relays
1
2
3
4
5
6
CN11
2,5MM 6W ST HEADER
To Speaker PCB CN1
PIC Standby Relay
Unreg for Relays
DGND
1
2
3
CN7
2,5MM 3W ST HEADER
R57
220R 2W Carbon
R108
220R 2W Carbon
PIC VI/Short
PIC DC
PIC CLIP
PIC Temp
Speaker A Relay
PIC Standby Relay
1
2
3
4
5
6
7
8
CN6
2,5MM 8W ST HEADER
To PIC
GENERAL NOTES
1.
2.
3.
4.
5.
Mains PCB Control
Speaker PCB Control
PIC Protection signals
Speaker Cable Short Circuit Detector
LK103
LK10MM
LK14
LK10MM
LK15
LK10MM
5
6
7
U8:B
LM393
LK102
LK10
LINK15MM
LK46
LK11
LINK15MM
LK45
LK10MM
1
2
3
4
5
CN4
2,5MM 5W ST HEADER
DGN
D
PIC VI/Short
PIC DC
PIC CLIP
Temp Sense
R116
10k
R115
10k
DGND
+5
V
PIC Temp
R63
910R
910 / (910 + 10k) with ZP221A501E
voltage gives 100deg C cutout
+5Volts
Temp Sen
se
R71
4k7
R70
10k
R117
4k7
Open Collector Output
Q8
BC337
LK39
LK10MM
LK38
R68
100k
R62
no stuff
C108
100N 50V X7R
C107
100U 16V EL
DGND
+5
V
Rev3: R65 Changed from 10R to 8R2
Rev4: R65 Changed from 8R2 to 4R7
Rev5: R65 Changed from 4R7 to 2R7
86-756-8687998
To enhance viewing, please print to A3
8
Summary of Contents for Azur 540A V2
Page 37: ...7915 U2 7805 U3 7815 U4 LM393 U8 TC9163AF U11 37 ...
Page 40: ...Front Panel Mains PCB MPSA14 Q4 BC337 Q1 Q2 PIC16F72 I SP BA6218 U1 M74HC4094 U3 40 ...
Page 41: ...TSOP1836 U4 A BUS PCB BC337 Q1 Q2 Q3 Q5 BC327 Q4 4011 U1 TSOP1836 U2 41 ...
Page 42: ...TSOP1837 U3 OP4N25 U4 NJM5532 U5 U6 7812 U7 42 ...