2 Theory of Operation (continued)

2.2 DC Auxiliary Power Circuit (continued)

Located at NH-SYS-M board (System MCU and Control Circuit)

RM42

RM43

 

5VS

 

K-ON

 

KEY_ON

 

CM24

(21)

 

G1

 

(a)The input of DC auxiliary power circuit is from positive battery.

(b)MCU detects the “on” key (on LCD board) status through KEY-ON(21)

AUXON

RM22

AUX-ON

(64)

RM26

AUXOFF

AUX-OFF

(44)

 

(c)When AC auxiliary power circuit is activated and battery is present, AUXON (64) is high and DC auxiliary power circuit will be on.

(d)If AUXOFF (44) is high during backup mode, DC auxiliary power will be off.

2.3Auxiliary Power Failure Detection

Located at NH-SYS-P board (Auxiliary Power for System, Detect Circuit for Voltage and Current)

RP20

DP11

+12VS

 

RP18

 

+12VB

QP8

ZDP5

 

RP19

 

G1

DP12

RP23

 

+12VS

 

RP21

 

+12VP

QP9

ZDP6

 

RP22

 

AUX-FAIL

QP10

RP24

G1G1

Located at NH-SYS-M board (System MCU and Control Circuit)

5VS

RM34

RM35

AUX-FAIL

 

AUXFAIL

CM23

(71)

G1

+12VP is from AC auxiliary power and +12VB is from DC auxiliary power. During AC mode, +12VP and +12VB should both be live. If one or both of them fails, MCU can detect auxiliary power failure through AUXFAIL (71) (low active).

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Tripp Lite SU60KX manual Theory of Operation, DC Auxiliary Power Circuit, Auxiliary Power Failure Detection