One wire alternators started out as being born from a typical 10SI Delco internally regulated alternator. The basic original 10si came on the scene in the early 70s and lasted until the late 80s. Originally it had to have excitation wires plugged into it to electrically excite the internal voltage regulator. Aftermarket companies came up with the "one wire" internal regulator that excites off of RPMs. This does away with the two wires that plug in on a typical 10 SI. Keep in mind that you still have the battery terminal or output terminal on the rear of the alternator. This wire makes a bath back to the battery in some manner and is the only wired needed to the alternator, hence the "one wire" alternator. It makes for a cleaner wiring set up. The replacement regulators were called "self exciting" regulators and were a direct replacement of the original reglator without any modification. A down side to the original self exciting regulators was that the rpms to excite the alternators was to high to work well on some farm applications or even some automotive applications that had low rpm motors. This has since been solved with faster cut in regulators at lower rpms. What is so nice about using the delco 10 SI alternator in chrome or the old fashion version, is that they can be built to about whatever amperage you want up to around 80 amps if its done correct. There are kits that take them up higher but most dont last long to do the heat that is created. If you need higher amperage like this I typically suggested moving out of the 10SI and into the 12SI or even the later model CS-130 that could be modified into a one wire alternator. Hope this info helps out.
Ken
www.classicgenerator.com
