Battery
| ID |
Type |
+ |
- |
Function |
| B1 |
BR-2/3A 3V |
R9(B) |
Digital Ground |
Configuration Memory Backup |
Capacitors
| ID |
Type |
+ |
- |
Function |
| C1 |
22000uF Electrolytic |
+8V Unregulated |
Digital Ground |
Smooth Input to +5V Regulator |
| C2 |
F104Z 25V Ceramic parallel with C1 |
+8V Unregulated |
Digital Ground |
Smooth Input to +5V Regulator |
| C3 |
10uF 16V |
+5V Rail |
Digital Ground |
Smooth Output from +5V Regulator |
| C4 |
F104Z 25V Ceramic parallel with C3 |
+5V Rail |
Digital Ground |
Smooth Output from +5V Regulator |
| C5 |
2200uF 25V |
+15V Unregulated |
Analog Ground |
Smooth Input to +12V Regulator |
| C6 |
F104Z 25V Ceramic parallel with C5 |
+15V Unregulated |
Analog Ground |
Smooth Input to +12V Regulator |
| C7 |
10uF 16V |
+12V Rail |
Analog Ground |
Smooth Output from +12V Regulator |
| C8 |
F104Z 25V Ceramic parallel with C7 |
+12V Rail |
Analog Ground |
Smooth Output from +12V Regulator |
| C9 |
2200uF 25V |
Analog Ground |
-15V Unregulated |
Smooth Input to -12V Regulator |
| C10 |
F104Z 25V Ceramic parallel with C9 |
Analog Ground |
-15V Unregulated |
Smooth Input to -12V Regulator |
| C11 |
10uF 16V |
Analog Ground |
-12V Rail |
Smooth Output from -12V Regulator |
| C12 |
F104Z 25V Ceramic parallel with C11 |
Analog Ground |
-12V Rail |
Smooth Output from -12V Regulator |
| C13 |
10uF 16V |
R11(A) |
Digital Ground |
Smooth R11 Input to Buffer Network |
| C14 |
F104Z 25V Ceramic |
+5V Rail at U1(14) |
Digital Ground |
Smooth +5V Input to Buffer Network |
Diodes
| ID |
Type |
K |
A |
Function |
|
| D1 |
C4P03Q |
K1:J1(1), K2:J1(3) |
+8V Unregulated |
+5V Rectifier |
|
| D2 |
Black, T85 8-B |
+15V Unregulated |
J1(4) |
+12V Rectifier |
|
| D3 |
Black, T85 8-B |
+15V Unregulated |
J1(6) |
+12V Rectifier |
|
| D4 |
Black, T85 8-B |
J1(6) |
-15V Unregulated |
-12V Rectifier |
|
| D5 |
Black, T85 8-B |
J1(4) |
-15V Unregulated |
-12V Rectifier |
|
| D6 |
Orange Glass, Yellow Stripe |
R1(B), R2(B), R7(B) |
D7(A) |
|
|
| D7 |
Red Glass, Black Stripe, 6B |
+8V Unregulated |
D6(A) |
|
|
| D8 |
Orange Glass, Yellow Stripe |
D9(K), Q4(C) |
+5V Rail |
|
|
| D9 |
Clear Glass, Red Stripe |
D8(K), Q4(C) |
R9(A) |
|
|
Fuses
| ID |
Type |
Function |
| F1 |
5A 125V Fuse |
Protect +5V Rail |
| F2 |
500mA 125V Fuse |
Protect +12V Rail |
| F3 |
500mA 125V Fuse |
Protect -12V Rail |
| ID |
Type |
Function |
| J1 |
6-Pin Molex KK-396 |
AC Input from Transformer |
| J2 |
10-Pin Molex KK-396 |
Connection to CPU Board |
| J4 |
13-Pin Molex KK-254 |
Connection to Audio Board |
| J1 Pin |
Function |
| 1 |
8 Vac (0-deg) |
| 2 |
Digital Ground |
| 3 |
8 Vac (180-deg) |
| 4 |
15 Vac (0-deg) |
| 5 |
Analog Ground |
| 6 |
15 Vac (180-deg) |
| J2 Pin(s) |
J4 Pin(s) |
Function |
| 1 |
1 |
Backup Battery |
| 2 |
2 |
Power OK |
| 3 |
3 |
Reset |
| 4,5 |
4,5 |
Digital Ground |
| 6,7 |
6,7 |
+5V |
| 8 |
8,9 |
+12V |
| 9 |
10,11 |
Analog Ground |
| 10 |
12,13 |
-12V |
Integrated Circuits
| ID |
Type |
Function |
| U1 |
74HCU04 |
Hex Inverter used as buffer array |
| U2 |
3052V |
+5V Regulator |
| U3 |
7812 |
+12V Regulator |
| U4 |
7912 |
-12V Regulator |
+5V Regulator (3052V)
| Pin |
Connection |
| Input |
+8V Unregulated |
| Output |
+5V Rail |
| Ground |
Digital Ground |
+12V Regulator (7812)
| Pin |
Connection |
| Input |
+15V Unregulated |
| Output |
+12V Rail |
| Ground |
Analog Ground |
-12V Regulator (7912)
| Pin |
Connection |
| Input |
-15V Unregulated |
| Output |
-12V Rail |
| Ground |
Analog Ground |
Hex Inverter / Buffer Array (74HCU04)
The hex inverter is used as a buffer array with a voltage divider (R5 & R6) providing hysteresis to avoid flapping the reset signal as the analog voltage input comes online.
You can find a good explanation of the concept on StackExchange.
Only five of the six inverters are used. Pins 12 & 13 are not part of the buffer array.
| Pin |
Connection |
Function |
Hypothetical Value |
| U1(1) |
C13(+), R11(A) |
Input for Pin 2 (1A) |
1 (System Input) |
| U1(2) |
R5(B) |
Invert Pin 1 (1Y) |
0 (Invert P1) |
| U1(3) |
R6(B), R5(T) |
Input for Pin 4 (2A) |
0 (Same as P2 through R5) |
| U1(4) |
Pin 5 |
Invert Pin 3 (2Y) |
1 (Invert P3) |
| U1(5) |
Pin 4 |
Input for Pin 6 (3A) |
1 (Same as P4) |
| U1(6) |
Pin 11, R6(T) |
Invert Pin 5 (3Y) |
0 (Invert P5, Same as P3 through R6) |
| U1(7) |
Digital Ground |
GND |
|
| U1(8) |
Reset Signal Output |
Invert Pin 9 (4Y) |
0 (Invert P9, System Output) |
| U1(9) |
Pin 10 |
Input for Pin 8 (4A) |
1 (Same as P10) |
| U1(10) |
Pin 9 |
Invert Pin 11 (5Y) |
1 (Invert P11) |
| U1(11) |
Pin 6, R6(T) |
Input for Pin 10 (5A) |
0 (Same as P6, Same as P3 through R6) |
| U1(12) |
[None] |
Invert Pin 13 (6Y) |
|
| U1(13) |
+5V Rail |
Input for Pin 12 (6A) |
|
| U1(14) |
+5V Rail |
Vcc |
|
Resistors
| ID |
A |
B |
Function |
| R1 |
Digital Ground |
R2(B), R7(B), D6(K) |
|
| R2 |
Q1(B) |
R1(B), R7(B), D6(K) |
|
| R3 |
Q1(C), Q2(B) |
+8V Unregulated, D7(K) |
|
| R4 |
R11(B), Q2(C) |
+5V Rail |
|
| R5 |
|
|
Voltage Divider to add hysteresis to buffer network |
| R6 |
|
|
Voltage Divider to add hysteresis to buffer network |
| R7 |
Q3(B) |
R1(B), R2(B), D6(K) |
|
| R8 |
Q3(C) |
Q4(B) |
|
| R9 |
D9(A) |
B1(+) |
|
| R10 |
Analog Ground |
Digital Ground |
|
| R11 |
C13(+), U1(1) |
R4(A), Q2(C) |
|
Transistors
| ID |
Type |
B |
C |
E |
| Q1 |
C1815 NPN |
R2(A) |
R3(A),Q2(B) |
Digital Ground |
| Q2 |
C1815 NPN |
R3(A),Q1(C) |
R4(A),R11(B) |
Digital Ground |
| Q3 |
C1815 NPN |
R7(A) |
R8(A), Power OK Signal |
Digital Ground |
| Q4 |
A1015 PNP |
R8(B) |
D8(K), D9(K) |
+5V Rail |
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