voltage regulator VS cut out in 6 V system

A generator used with a cutout alone usually has three brushes and the third brush serves to set the generator's charging current which it holds independent of the battery's need for charging and the needs of other loads. In the 30s, cars used three brush generators and smart drivers turned on the headlights after they had driven far enough to have charged the battery. In this scheme the generator will overcharge the battery if that subterfuge is not done. An overcharged battery looses lots of water and if that is not regularly replenished the battery dies an early death.

A voltage regulator holds the generator to 7.1 volts (ideally) which is the precise voltage that the battery chemistry works best with. That will charge the battery as fast as possible, but will not over charge it. The battery current decreases with time of charging. The generator current varies to supply only the needs and the battery can last years instead of months. This is also more energy efficient because the generator puts out only the power needed, not all it can all the time.

In AC tractors the light switch also varied the generator charging current, when wired right, and using a three brush generator with a cutout.

Gerald J.

The 6 volt starter will generaly stand 12 volts, but with a magneto it can cause hard starts because sometimes the starter turns the engine too fast for the impulse start of the magneto to operate which means poor spark.

Gerald J.