REV 2.3
© 2012 TCW Technologies, LLC.
4
Product Details and General Information:
Back-up Power Master Switch:
The IBBS has one input switch connection as identified in the wiring diagrams: Back-up
Power Master. This switch enables back-up power from the IBBS system to be
available on the output wires when power on the normal aircraft bus falls into the range
of 10-11 volts.
If the back-up power master switch is “ON” and normal aircraft power falls into the
range of 10-11 volts, then the internal back-up battery will be connected to the output
and be utilized to supply back-up power to the connected load.
If the normal aircraft power bus is above 11 volts, then the outputs are energized with
normal aircraft power and the back-up battery remains off-line. This pass through
power operation occurs regardless of the state of the Back-up Power Master switch.
Having the Back-up Master Switch ON allows for automatic transfer of power during the
transition between normal operation and back-up operation.
The “Info wire”:
The IBBS includes an “info” wire as shown in the wiring diagram. The “info” wire may
be used in conjunction with other equipment such as EFIS systems or engine monitors
to provide information regarding the state of the back-up battery system. When the
IBBS is off-line and normal aircraft power is available on the input of the IBBS, the “info”
line may be read to determine the internal battery voltage. A nominal battery with a full
charge will read between 12 and 15 volts. When the IBBS is on-line providing back-up
power, the “info” line is pulled to a logic low level to signal connected equipment that the
system is currently running on back-up power.
Alternately, the “info” wire may be connected to a warning lamp to indicate that the main
aircraft bus is low and the back-up bus should be switched on. See wiring diagrams for
LED warning lamp usage.
The Charging System:
The IBBS automatically maintains its internal battery pack. The internal charging circuit
monitors the state of the internal battery and recharges it as necessary when the aircraft
is operational. The maximum input current for battery recharging is 1.8 amps. When
the aircraft power bus is in the off state, a maintenance current of up to 4 milliamps may
be drawn from the aircraft battery to ensure the back-up battery remains charged. The
maintenance charge current is drawn from the input wire marked: Aux Battery Trickle
Charge. If the internal battery is fully discharged for any reason it may require up to
two hours of recharge time with the normal aircraft bus on. NOTE: Do not attempt to
recharge the IBBS product by using an external battery charger directly connected to
the input of the IBBS. Battery chargers typically provide pulsating voltages that will
damage the IBBS product if the system is not connected to a typical primary aircraft
battery.
