The BA-14/28-50 Aircraft Ramp Power Supply and Battery Charger is a multi-purpose aircraft flight line service and maintenance tool. The unit has a filtered 14 & 28 volt DC power supply with up to 50 amperes capability for tests of aircraft electrical systems and a secondary mode for recharging run-down batteries. The BA-14/2850 plugs directly into the aircraft APU connector and is tied to the electrical system when the master switch is activated. Selection of output voltage is by a front panel switch which is protected by a switch guard. Closing the guard forces the switch to the 14 volt position.Version (EDMO# BA14/28-50) is designed as a power supply and battery charger unit with 14 and 28 dual voltage, 50 amps, 110 volt input, 60Hz frequency, and includes the Cessna plug.