NEC Univerge sv8500 Manual page 2828

8.5.7 PA-PW55-B (PWR)
General Function
The PA-PW55-B (PWR) circuit card supplies operating power to circuit cards accommodated in the PIM. The
-48V input power source, which is converted to +5V, -5V, and +12V, is distributed to each circuit card in the
associated PIM. This card is also equipped with a Ringing Generator Unit (RGU), whose output frequency and
voltage can be selected among 20Hz, 25Hz, 75Vrms, 90Vrms by key setting on this card. In addition, a Howler
Tone circuit resides on this card.
PA-PW55-B (PWR)
REL
Note: The +80V input is required for activating Message Waiting Lamps (MWLs).
Location of PA-PW55-B (PWR) card within the System
DC-DC
+5V, +12V, -5V
RGU
CR (For LC)
HOW
HOW (For LC)
SUB
PWR
NFB
-48 V (For LC, TRK)
-48V
VOL.3-341
CHAPTER 2
PA-PW54-B (DPWR)
NFB
+80 V (For MWL)
+80V (Option) Note
TERMINAL-RELATED DEVICES
DC-DC
RGU
HOW
REL
SUB
PWR