OK- - - -it's time for "voltage regulators 101"- - -or you could just read the article I wrote in the tech tips section. There are three units inside the regulator that's commonly used with a DC generator. The cutout relay is just an on-off switch that disconnects the battery from the generator with the engine off to prevent the battery from discharging back through the generator. If that unit sticks, it's disaster time, with both the generator and regulator, plus the wiring, sometimes, going up in smoke or flames. The cutout closes when the generator voltage rises to a little above battery voltage, resulting in a flow of current from the generator to the battery.
If the battery is low, the generator will go to its full output to try to recharge the battery quickly. A generator can produce very high current flow under these circumstances, so it must be protected by the current regulator. This is the unit in the regulator with big, heavy windings and a set of points to interrupt the field current and reduce generator output anytime the current rises too high. High-current situations result in LOW voltage, because the resistance of the battery is low. As the battery increases in charge, the voltage rises, and the current drops. The current regulator stops working, and the third unit, the "voltage regulator" takes over. The voltage regulator setting is usually about 1.5 volt higher than the battrery voltage, so a generator charging against a fully-charged 6 volt battery will be regulated at about 7.5 volts. This prevents overcharging the battery. 12 volt regulators are set at around 14.5 volts or slightly more.
Hope this helps!
Jerry
