Power Management Unit Circuit Description - Tait TB8100 Service Manual

12 Power Management Unit Circuit
Description
TB8100 Service Manual
© Tait Electronics Limited September 2006
The TB8100 power management unit (PMU) provides stable, low-noise
28VDC outputs to power the TB8100 base station. The PMU is made up
of a number of individual boards and cards which comprise two main
modules, the AC module and the DC module. The auxiliary power supply
board is optional.
The AC module accepts an input of 115/230VAC 50/60Hz nominal, and
the DC module accepts an input of 12VDC, 24VDC or 48VDC
(depending on the model). Both modules provide the following outputs:
28VDC high current (PA)
28VDC low current (reciter)
13.65VDC, 27.3VDC or 54.6VDC low current (with the optional
auxiliary power supply board).
The PMU is available in three main configurations:
AC PMU (AC input only)
DC PMU (DC input only)
AC and DC PMU (both the AC and DC modules are fitted to allow both
AC and DC inputs).
If both the AC and DC modules are fitted, the PMU uses the AC input by
default, and provides battery back-up by operating from the DC input if the
AC input is interrupted. The changeover from AC to DC input, and from
DC back to AC input, is breakless. This allows the base station to operate
without interruption.
The power supply card allows efficient use of the DC input at low power
requirements. The optional auxiliary power supply board provides output
voltages which are different from the 28VDC required by the TB8100 base
station.
Figure 12.1 on page 202
along with the main inputs and outputs for power and control signals. The
table which follows shows which boards and cards are fitted in each module.
The locations of the main circuit blocks on the boards are shown in
Figure 12.5 on page 211
1. Because the DC module is designed to run from a battery, there will be a
minimum start-up voltage when operating on DC only (refer to the
TB8100 Specifications Manual (MBA-00001-xx) for more details).
shows the configuration for an AC and DC PMU,
and Figure 12.6 on page

Power Management Unit Circuit Description

1
nominal
213.
201