More test results
Given that a constant voltage supply (like the ones referred to in this thread) are less effected by changes in load than a resistor the question becomes how much load variation is there. Sunday my son and I went out and conducted the following experiment. On the ground we get 12 seconds to run the trim stop to stop, at 70 mph in the air that speed was relatively unchanged, at 115mph (not an easy test) the trim took 18 second to go end to end. Given the stick forces required to keep the plane level during the last test I suspect it represents significantly more load than would be seen in normal use.