Cut outs were used on the un-regulated 3-brush or 5-brush 6-volt generators. The later 2-brush 6-volt generators used a 3-pole regulator. Most 12-volt systems use a 2-brush generator or an alternator. 12-volt generators also used a 3-pole voltage regulator that has a cut out at one of the 3 internal poles. The other 2-poles were current limiter and voltage regulator functions. The later alternator upgrades usually include an internal solid state regulator.