
User’s Manual
197
Use these guidelines to define the thresholds when each element needs to be considered.
Voltage type—AC only.
Voltage threshold—AC input voltages within 3 V of the minimum specified input volt-
age for Options 3 or 4, within 5 V of the minimum specified input voltage for Option 5.
Significant current
more than 1 A to user circuits for 2 A regulator
more than 250 mA to user circuits for 1 A regulator
High ambient temperatures—If all three of the above factors are present, then look at
Table D-1 to determine whether the operating temperature creates an issue. The capaci-
tor lifetimes are listed at the specified temperatures for the existing 1000 F capacitor
at position C34 on the PowerCore module by itself and with an additional user-supplied
1000 F capacitor installed between the DC+ line (from pin 4 of J4) and ground on the
motherboard:
Table D-1. Effects of Additional 1000 F Filtering Capacitor
Ambient
Temperature)
Lifetime with One 1000 F
Capacitor on PowerCore
Module
Lifetime with Additional
1000 F Capacitor
on Motherboard
25°C
Capacitor lifetime not a factor
40°C
Capacitor lifetime not a factor
50°C
18 years
36 years
60°C
9 years
18 years
70°C
4.5 years
9 years