You are correct for alternators and generators, as used on cars, and the '88 and up Goldwing, and for portable gas powered generators, but not for motorcycle STATORS. At idle their ouput is usually low, sometimes so low that prolonged idling will drain the battery. But at higher speeds, they run wide open. There is no output control on them. Their output is not based on load like a car. Excess current is shorted (or to quote the manual, "shunted") to ground, through a resistor in the regulator/rectifier. The R/R is a heat sink, and will normally handle the heat caused by this. But on the '85 Goldwing 1200 LTD, which is fuel injected, the stator is a whopping 500 watts, and it is putting out 500 watts at all times when engine speed is high enough. A carbed Goldwing only puts out 350 watts. Now, while I consider this a stupid design, it is the way most motorcycle charging systems work. And with lower output stators, it is not usually a problem, other than generating to much current, then disposing (wasting) it as heat. But the R/R on the LTD simply did not have the capacity to handle all the current that was being dumped into it. A larger capacity R/R would have solved the issues I was having with it (R/R overheating, getting so hot it actually set the insulation on some wires that were touching it on fire) it is still a really dumb design. Most motorcycles continue ton use this design today. You will find few (I only know of one) motorcycles where the alternator field output can be controlled. It looks like from your user name you are an amateur radio operator. So am I. Have been since 1983. I also work on auto OBDII systems for a living. I never understood how motorcycle charging systems worked either until getting that Goldwing. I had never had any problems with them.