Patent ID: 8813505

Claim:
A method for conditioning a power supply for starting a jet engine having an electrical starting system with an auxiliary power unit (APU), which is started by an AC starter/generator (AC S/G), which is started by a DC power supply, the method comprising: converting the DC power supply to a first AC power supply having a first set of electrical characteristics suitable for the AC S/G; starting the AC S/G with the first AC power supply and outputting a second AC power supply having a second set of electrical characteristics suitable for starting the APU; starting the APU with the second AC power supply and outputting from the APU a third AC power supply having a third set of electrical characteristics; converting the DC power supply to a fourth AC power supply that is combinable in parallel with the third AC power supply; combining in parallel the third AC power supply and the fourth AC power supply to form a fifth AC power supply having a fifth set of electrical characteristics suitable for starting the jet engine; and starting the jet engine with the fifth AC power supply.