[Milsurplus] LM-18 and AC PS Questions.. More

[brunneraa1p at comcast.net]

From: J Forster <jfor at quik.com>
> Maybe not. The load is essentially constant and there is feedback on the 
> generator output which would compensate for line changes and windage change with 
> altitude (if that's an issue).    I can think of no alternate reason for the operator controls.

The reason for the controls (capacitor selection) is to set the capacitance value as near to optimum as possible to neutralize armature reactance.  Thereafter there is no need to touch them.  The carbon pile then compensates for changes in windage or input voltage by varying generator field excitation.  Note that they also used saturated-pole generators which were inherently self-regulating, (no carbon pile) but they still used the series capacitors.

In initial setup the voltage level is set by a carbon pile setting, and thereafter only small adjustment is possible with a pot on the M-G chassis.  A saturated pole generator of course sets itself, and is not adjustable

Richard Brunner, AA1P