NDA-24296 CHAPTER 2
Pag e 51
Revision 1.0
PA-PW54-A
Dual Power

PA-PW54-A

Dual Power

1. General Function
The PA-PW54-A (DPWR) circuit card supplies operating power to circuit cards located i n the PIM. The -
48 V input power source, which is converted to +5 V, -5 V, and +12 V, is distributed to each circuit card in
the PIM. This card a lso has a Ringing Generator Unit (RGU), whose output frequency and voltage can be
selected from 20 Hz , 25 Hz, 75 Vrms, 90 Vrms by switch setting on this card. In addition, a Howler Tone
circuit resides on this card.
Figure 2-16 Location of PA-PW54-A (DPWR) Card in the System
Note: The +80V input is required for activating Message Waiting Lamps (MWLs) .
HOW (For LC)
CR (For LC)
+5V, +12V, -5V
DC-DC
RGU
HOW
SUB
PWR
REL
NFB
PA-PW55-A (PWR) PA-PW54-A (DPWR)
-4 8 V (For LC, TRK )
DC-DC
RGU
HOW
SUB
PWR
REL
NFB
-48 V
+80V (Option) Note
+80 V (For MWL)