User's Manual

Doc. No.
Rev.
Date
1.00
2011-12-08
Damm Cellular Systems A/S, Denmark
TETRAFLEX
®
V7.5 MANUAL - Power Supply for BS41x
TetraFlex® 7.5 Manual 4-26
4.6 POWER SUPPLY FOR BS41X
4.6.1 Introduction
The BS41x Base Stations are provided with a flexible Power Supply scheme allowing it to run
in a variety of different configurations. It can run from either mains AC directly, run from a DC
battery source or a combination hereof with battery charging.
The different BS versions have space for from 2 to 4 PS411 Power Supply units running in
parallel with full power share on all sections. Redundant n+1 operation is provided as all
Base Stations can run with full specification with one PS411 out of operation.
All the variants can be connected with an external –48V lead-acid battery and has all the
needed circuitry to charge the battery
The PS411 Power Supply contains 4 major parts:
 AC Rectifier providing –48V DC
 DC/DC converter providing +26VDC (for the TX PA)
 DC/DC converter providing +14V DC (for all other BS parts)
 Microprocessor (for charging control, monitoring and alarm generation)
The following number of PS411 is needed depending on the number of carriers installed in
the Base Station:
Carriers
No redundancy
N+1 redundancy
1 carrier
1 x PS411
2 x PS411
2 carriers
1 x PS411
2 x PS411
3 carriers
2 x PS411
3 x PS411
4 carriers
2 x PS411
3 x PS411
5 carriers
2 x PS411
3 x PS411
6 carriers
3 x PS411
4 x PS411
7 carriers
3 x PS411
4 x PS411
8 carriers
3 x PS411
4 x PS411
4.6.2 Rectifier
The Rectifier section converts the mains AC input to –48VDC, which can charge the battery
and feed the two DC/DC converters. The connection of the battery is optional.
The Rectifier accepts a wide voltage input range, supporting the 3 different standards used
worldwide, namely 100V, 115V and 230V. It also accepts both 47Hz and 63Hz. No jumper or
setting changes are needed to switch between the variants. However a change of the size of
the fuse mounted from the front of the PS411 is needed when changing from 230V to
100/115V. The values are marked on the front plate.
The –48V DC output is fed to a common –48V power rail on the back plane of the cassette. A
power sharing circuit ensures close to equal load on all inserted PS411.