The Stovebolt Site Forums The Shop Area The Electrical Bay Generator vs Alternator

I know I need to convey my '54 6100 to 12 volts as I need to install electric brake controller for my trailer. The question is what are the pros and cons of using a 12 volt generator vs 12 volt alternator other than originality looking.

Found this on the web:
An alternator is more efficient at charging across much of the RPM range of the engine. It can produce a higher output at lower RPM by increasing the excitation in the field windings. At higher RPM, the output can be reduced by lowering the field excitation. This is done automatically and electronically by the alternator regulator circuitry.

With older vehicles, especially in winter or at night when you had the lights and heater on, the output from the generator at low RPM wasn’t enough to keep the battery charging properly to keep up with the demand.
Alternators also have slip rings which are much less prone to wear than the brushes and commutators of DC generators.

Also, alternator is more compact and most often contains the voltage regulator, which cleans up wiring.

Availability is more widespread if you happen to need a replacement too.

Besides the out put advantage the reliability is a big factor also. Back before alt. the gen. would last about 25,000 miles. If not controlled properly it could distruck any time. The regulator could fail at any time. An alt. will generally last 75,000-100,000 miles.
George

One fact that is either overlooked, or maybe not known at all is the stability of the output of the alternator VS the generator. Since the charging current is broken up into pulses several times a second by the commutator of the generator armature as it passes under the brushes, the generator produces a very "dirty" current flow when viewed on the screen of an oscilloscope. Back when the most sophisticated piece of equipment on a vehicle was a tube-type AM radio, charging the battery with pulsating DC current didn't present much of a problem. Now, with the possibility of having all sorts of fancy electronic devices onboard is present, an alternator is the obvious choice for anything other than a truck that competes in car shows where numbers-correct originality is important. Just don't get tempted to use one of the horrendously expensive fakes that try to put an alternator into an original-looking "generator".

I don't know of anyone who would want to subject a smart phone, a GPS, electronic ignition, or a fancy sound system to the choppy output of a DC generator. Solid state electronics don't play well with that kind of signal.
Jerry

Well if anyone has a '54 235 and converted it to 12 volt with a 10si alternator, which clock position did you use?

Use whatever works- - - -clocking a housing is a 5-minute operation, at most, and that's if you take a short coffee break.
Jerry

kc, my LCF still has the original style generator and I think it's original to the truck according to the numbers. I have added clearance lights on the grain box but everything else is stock. All 12 volts, no radio. The generator is rated at 25 amps output. It is stressed to keep up when running the lights and new heater motor, I wouldn't think twice about going with an alternator.