A SERVICE OF

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67
PRELIMINARY
2 Theory of Operation (continued)
2.21 Control Circuit for Power Module
Located on NH-SYS-R board (Circuit for RS232, Output Dry Contact, Parallel Port, Connector to connect with each Power Module,
Circuit for 2 Slots)
Located on NH-SYS-M board (System MCU and Control Circuit)
(a) VS is the voltage source for the parallel signal bus. CENTRAL_OK signal is controlled by the system MCU’s watchdog circuit.
(b) The BYPOK signal indicates that the system MCU is functioning properly.
VS
RR106
RR1 00
G1
QR11
+12VSF
1
2
4
3
UR42
5VS
QR12
RR1 11
RR1 08
G4
RR105
CENTRAL_OK
RR8 1
CR5 6
1
2
4
3
UR35
RR7 8
BYP _ OK
+12VS
DR13
+12VSF
G4
BYP OK
QR14
RR1 38
+12VSF
RR1 37
COM
9
1B
1
1C
16
2B
2
2C
15
3B
3
3C
14
4B
4
4C
13
5B
5
5C
12
6B
6
6C
11
7B
7
7C
10
GND
8
UM5
ULN2003A
G1
LED1
LED0
LED3
LED2
LED5
LED4
BYP _ OK
(70)
(73)
(74)
(75)
(76)
(77)
(78)
U-LED0
U-LED1
U-LED2
U-LED3
U-LED4
U-LED5
CENTRAL _OK