Well here goes (gotta Love it) And best wishes and thanks for the discussion on Thanksgiving day!!! Dear Dell. with respect and good spirits. A Bosch solid state regulator to adapt 6v generators to 12 volt operation is identical to using a 12 volt conventional (mechanical points and coils) regulator to do the same thing.
When a 6 volt DC generator is operating at 6volts, it is making a series of overlapping pulses that go from about 6.5 volts to 7.5 volts. These pulses are the result of the commutator engaging ever different segments onto the stationary brushes. These are sufficient to operate the electrical load of the tractor/car or whatever, when the lights are on or the battery needs to be charged. As the load increases, the regulator just increases the field (grounding current by reducing the resistance in the ground (field) circuit. This keeps the voltage at about 7.2 to 7.6 volts.
The use of a 12 volt battery (polarity is a different animal and we will assume negative ground and correctly polarized gen) and regulator now places 12 volts in the system. The 6v generator is not limited to 7 or so volt output, it can produce much more than that if allowed to do so.
When started it self excites to get up enough voltage to begin charging the battery. thus the voltage climbs until it does so. If connected to a 6v battery it climbs to 6.3 and above and latches in the mechanical cutout relay in the mechanical vr, or begins passing current through a power diode in a solid state vr. This begins charging the battery and supplying current to the loads. The vr senses the voltage rise and begins cutting back the field current until the voltage rise stops at about 7.2 volts (a nice strong charge voltage that will top off the battery and make those miserable lights operate as brightly as they can.
If it is connected to a 12v battery and regulator, the voltage rises to 12 volts (the gen cannot self regulate its output) and the cutout or power diodes in the VR begin to conduct charge current to the battery. Voltage rise in this case is now limited to 14.2 to 14.7 volts. All seems well but is not.
The 6 volt generator is designed to have windings turns and wire size for operation in the 7 volt range of continuous duty. The Ohm specification of the windings is provided such that 7.4 volts will not over heat the windings when running (pumping air through the housing to cool it).
The the field windings are now subjected to radically higher current due to the fact that they are (basically a 6v bulb running on 12 volts) They are much bigger and more robust than a light bulb filament, and will tolerate the overload longer, but they do heat up excessively. As in the 6v on 6v above as the load increases (lights on or discharged battery) the field current increases to maintain 14.2 volts and then things get melty around the windings, and smoke begins to curl up when it is shut off.
If the field windings are swapped out to 12 volt, it will last substantially longer, but it is still loading the armature windings beyond design intent.
The true reason for using a 12 Volt alternator is to reduce maintenance to NONE. Alternators are far less likely to need service and produce good current at lower RPM. They also have the rapid starting RPM of 12 volts to fire up a tweaked engine or in cold weather.
I can say that if used on light duty daytime show tractors, the Bosch regulator would work. Is it a solution? well it doesn"t reduce the generator maintenance, it actually increases it by overloading the field, and passing 12 volts through a 6 volt design.
It does work, but for working tractors with higher intensity lights than the meager OEM candles on sticks, it is poor (opinion). May Peace find you and yours this day. Jim
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