Brauniger ALPHAMFD - 5.9 Voltmeter; 5.10 Back-Up Power Supply

28
5.9 Voltmeter
After pressing the >FUNC/SET< key twice, the altitude
display changes to temperature and the real-time display
changes to voltage indicated by the >VOLT< icon. If the
voltage of the aircraft drops below 11.5 V an audio/video
alarm sounds through the Intercom and the real-time display alternates with the
voltmeter display. If the ALPHAMFD switches to emergency power supply, the
voltage of the back-up battery will be displayed.
5.10 Back-Up Power Supply
If the aircraft power was cut off during flight, the ALPHA
ALPHAALPHA
ALPHAMFD would stop working.
Therefore the ALPHA
ALPHAALPHA
ALPHAMFD has an integrated back-up power supply. The instrument
switches automatically over to the back-up battery when the normal power supply
drops below the safety margin of 11.0 V or is cut off completely. The switch to back-up
battery is indicated by an alarm through the Intercom the flashing of the voltmeter
display and the red alarm flashlight.
The back-up battery is a normal 9V alkali-manganese 6LR61 block, which is stored in a
compartment on the side of the instrument. It can easily be replaced by opening the
drawer.
The ALPHA
ALPHAALPHA
ALPHAMFD checks the back-up battery every time it is switched on. If the
voltage of the back-up battery is too low and not sufficient to power the ALPHA
ALPHAALPHA
ALPHAMFD
in case of emergency, the message "BACK-UP BATTERY LOW" is displayed. The back-
up battery must be replaced as soon as possible!
For safety reasons, the ALPHA
ALPHAALPHA
ALPHAMFD can only be switched on when the normal aircraft
power supply is sufficient. It will only switch over to the back-up battery, when the
aircraft power supply is faulty during flight. This way the pilot cannot take off with a
faulty aircraft power supply!
WARNING! When the ALPHAMFD switches over to emergency power
supply by the back-up battery, the voltage of the back-up battery is indicated.
If this value drops to 7,2 V or below you must IMMEDIATELY exchange the
battery. You MUST NOT fly with a voltage of 7.2 V or below because the
emergency power supply can not be guaranteed!
WARNING! Depending on the wiring of the ALPHAMFD connection, the
ALPHAMFD might be completely disconnected from the aircraft power supply.
If you switch off your engine, the main power supply can be interrupted and the
ALPHAMFD will switch to emergency power supply. In this case, the
ALPHAMFD
will switch off automatically after 3 minutes. This will only happen,
if the
ALPHA
MFD
measures no air
speed during these 5 minutes. If air speed