Tait TB8100, Service Manual

Page: 204 / 306

204 Power Management Unit Circuit Description TB8100 Service Manual
© Tait Electronics Limited September 2006
AC Converter
The microprocessor can enable or disable the AC converter if the user needs
to test the DC module and battery back-up by simulating a failure of the AC
mains input.
The microprocessor monitors the output voltage and current, the
temperature of the AC module heatsink, and whether the AC mains input
is within the specified range.
DC Converter
The microprocessor controls the on/off function of the DC converter. It
also controls the mode of operation of the DC converter: normal mode,
hysteresis mode
1
, or deep sleep mode. Refer to “Hysteresis Mode” on
page 209 for details on hysteresis mode, and to “Standby Power Supply”
below for details on deep sleep mode.
Figure 12.2 PMU microprocessor functional block diagram
R
5V Supply
Flash
Programming
Supply
AC
Converter
DC
Converter
Auxiliary
Power
Supply*
Micr
opr
ocessor
Temperature
28V
Data
Run
Voltage Sense
Current Sense
Fan
Current Sense
Microprocessor
Supply
Temperature
Mains
Input
PA
Output
Reciter
Output
Auxiliary
Output
Battery
Input
Battery
Supply
On/Off
Standby
Power
Supply
Hysteresis Mode
Shutdown
Standby Supply
Present
Low Battery
Alarm On
*optional
Summary
Alarm On
Vpp
Vpp Enable
Fan Supply On
I C
2
Signals
Fan
Output
Summary Alarm
Output
Low Battery
Alarm Output
I C Port
2
Run
Data
Standby Supply Isolate
Mains OK
Shutdown
I
V
0V
0V
0V
1. A type of “sleep” mode available when the standby power supply card is not
fitted.