If you take the cover off the regulator, there are three wound-wire coils with contact points above them. The center coil, the one with the spring-closed points and the large wire winding, is the current regulator. The connector immediately in front of that coil is labeled "A" for "armature". The charging current going through that winding develops magnetism that pulls the points apart, and puts a resistance into the field coil circuit in the generator, dropping the output. By adjusting the spring tension on the points, the maximum current flow can be controlled. The magnetic coil with the finer-wire winding behind the "F" terminal has a similar effect on the field circuit, but it controls voltage, not current flow.
The operation of the current and voltage regulation coils is an either/or situation. They do not operate at the same time. With a low battery, the current regulator controls. Once the current drops and the voltage rises due to increased internal resistance in the battery, the voltage regulator takes over to prevent battery overcharging. If you want to protect the generator from overloading itself, adjust the regulator to deliver a maximum of 25 amps under low-battery conditions. The voltage regulator can still be adjusted to maintain normal voltage, even if the current regulator has a lower-than-normal setting.
Jerry
