McIntosh MC303 - Page 8

9
10
2
BACKUP POWER SUPPLY
750975 SCH
1
1
1
GRY
BLK/GRY
BLK
J15
J1
J2
3
1
4
2
K2
1
1
1
WHT
WHT/VIO
VIO
J12
J14
J13
1
1
J10
J11
AC N
AC FUSE
100V
20V
100V
20V
1
J3
1
1
J4
J5
1
1
J9
J8
D1
POWER TRANSFORMER PRIMARY
240V220V120V
2
6
8
4
1
3
5
7
PRIMARY
T1
3
1
4
2
K1
100V
t
RT1
t
RT2
J7
1
3300pF
C1
J6
1
J16:1
J16:2
[+] RLY TP [-]
TEST ONLY
NO CONNECTION
2
13
IN OUT
U1
.47uF
C3
.3A
t
R1
3300uF
C2
PGND
1
ORN
J21
9
PWR RLY
1
ORN
J22
1.82k
R2
31
2
Q1
PWR TRANSFORMER
THERMAL SWITCH
J23:11
9
+5VBU
GND
9
J23:1
J23:2
TO DISPLAY
FROM DISPLAY
J23:12
J23:3
J23:4
J23:5
J23:6
J23:7
J23:8
J23:9
J23:10
D4
D5
D2
D3
F1
0V
J4
12V