Velká Bíteš Turbojet Engine TJ20A Operation And Maintenance Manual - page 9
PP-42A
9
Caution!
The battery must be disconnected from the model during charging.
Attention!
Fire hazard! Li-Pol type batteries can explode if charging parameters are set
incorrectly. Always observe the instructions provided by the manufacturer of
the charger. When charging, the batteries must be under constant
supervision.
CAUTION
Supply voltage of 4,8V from the engine is brought on red wire of RC connector.
For example this supply voltage can be used as power supply of control. Maximal
current drain from the engine is 0,3 A. In case you do not need this additional supply
voltage, don´t wire it!!!!
3.
DESCRIPTION
3.1
Description of engine
Turbojet engine TJ20A is single-shaft engine with single-stage radial compressor, annular
combustion chamber, single-stage axial turbine and output nozzle.
At the compressor suction is located booster with break-in clutch enabling starting of this
engine from the cockpit net.
Induced air is compressed at radial compressor wheel, pass through radial and axial diffuser to
the combustion chamber, where is blend with evaporate fuel at evaporating piping. Hot gases
caused by fuel burning at combustion chamber expand through single-stage axial turbine and
exhale by high gear from output nozzle to the atmosphere and cause the thrust of this engine.
Axial turbine provides gear of the compressor. Rotor of this engine placed at 2 axial bearings
lubricated by fuel. Part of this engine is electronic board, this board process data from speed
sensor, exhaust gas temperature sensor and input air temperature sensor. Operation of this
engine is control by control unit. Control unit will check all connected accessories after
receipt of start direction and run starting of this engine automatically. Control unit take control
of starter, fuel sensor, starting and main fuel valve following data from all sensor. After
finishing of engine running will automatically start aftercooling with cyclical switching of
starter as long as temperature of exhaust gases will not drop below stated value.
Control unit works on the principles of model technology (variable width of pulse 1 – 2 ms
with recurrent frequence 50 Hz).
3.2
Wiring of harness
Harness of engine connected
according picture at clause No: 3.5.
Attention!
Cable connection to battery must be
red wire to +
,
black wire to -
.
Opposite (wrong) connection results in destruction of electronics!!!
3.3
Connect of fuel supply
After installation of engine to the application and harness connection follow fuel insertion.
Connect the fuel pipe from filter to the engine fuel input. See picture at clause No: 3.5.