The problem is with the 500 amps. Is this peak start current from zero
rotor speed, or an average during the start cycle.

Don't say you don't know. Measure it.

How much does it draw when you "soft start" it with a 12 volt source. What
happens if you ramp it up from 6 volts to 12 volts to 28 volts? What is the
PEAK current being drawn in the ramp-up mode?

Jim



"Martin" wrote in message
...
I need to design a device to help "cushion" the engagement of my starter.



The starter is 28VDC (drawing up to 500 Amps) on a T58-GE-3 turbine engine
installed in a non-aircraft application. I'm told this "starter slamming"
is
a 'weak link' on this engine and often causes starter failure.