I did some surfing, and found out some interesting things. Here is a link to a generator vaguely similar to mine:
http://www.usdieselengines.com/generator-welder.pdf There are some engine management schematics in it, operating instructions, etc. Unfortunately the electrical end is fairly different. Almost every one of this class of generator I've been able to find information on uses the resonant type of regulation, using mostly just a capacitor. (Such generators don't start heavy motors very well, and apparently don't tolerate _at_all_ capacitive (leading power factor) loads. And I believe they are relatively inefficient in that they burn excess input mechanical power as heat, rather than reduce the field and thus the mechanical load.) Yet mine has a more traditional electronic regulator. Nice, I suppose, when it's working. Not so nice when it fails. (It wouldn't be a problem if it were in a sealed box instead of being epoxy-potted. I can often fix crap like that.) I also found a link to a white paper on the theory of this low-cost regulation system: http://www.fieldlines.com/story/2006/6/14/23147/3970 Interesting reading. The upshot is that the cheap resonant regulator seems to operate, similar to a constant-voltage transformer, by running in saturation and burning excess mechanical energy as heat. They should be markedly less efficient at partial load as a result. And here is an interesting white paper on generator voltage regulator theory: http://lib.tkk.fi/Dipl/2007/urn009728.pdf In it I found the first plausible explanation of why my generator might have two separate excitation windings. One winding reacts to no-load conditions, and the other to short-circuit conditions. One is at the fundamental frequency, and the other is at the third harmonic. Together they span the range of loads from zero to shorted, and give a first-order response for regulation. In other words, the electronics of the regulator itself can be simplified if they're powered from the combination (series?) of these two windings. If this is indeed what I have, my generator is considerably better than the run of the mill. Except, of course, that it is broken. Regardless of its design sophistication, its construction seems no better than any other cheapie. And _don't_ get me started on epoxy-potting electronics! -- Jim _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
