That doesn’t ring true to me,as a general rule the fixed stator windings and the surrounding magnets are producing constantly and the amount of juice they produce is variable with engine revolutions.The rectifier changes the 3 phase A/C to D.C.and then when the battery is up to the preset voltage built into the regulator converts what is not required into heat,which is dissipated out through the fins on the rec/regulator.I did say in general because there are some very clever rec/regs about now that do this differently,but I do not know how they work,so cannot comment.I reckon if you disconnected the magneto whilst the engine was running it would self destruct due to uncontrolled voltage building up in the windings.That is why if the rec/reg.goes down it sometimes takes the stator with it.
