Mike-
I too am spending a bunch of time to educate myself on Model 'A' generators since I'm in the middle of an issue with one...
Went to your club site and found the article...
http://www3.telus.net/scmafc/Script Nov 11 Web.pdf (starts on page 5)
Found it interesting and informative - except for the info on the Fun Projects EVR.
I am sharing this only to clarify the info about the FR EVR, since I misunderstood it at first.
I corresponded with the maker of the FP EVR and suggested,
as you do in your article, that the FP EVR directs any un-needed charge being produced harmlessly to ground.
Here is his response to the line of thinking you & I both shared regarding this device: (kinda lengthy, but a good read...)
"Never does the VR direct any charge 'harmlessly to ground'. There is NO wasted power. If you measured the HP being taken from your motor by the generator, you would find that there is direct correlation between the HP drawn from your motor and the actual load being placed on the generator. The maximum current that your generator can safely put out is 15 amps at nominal 6V battery system operation (7V being the asssumed charging and operating voltage). The VR does NOT waste power - not even small amounts. When putting out 5 amps, you would be putting out 7V x 5A = 35 watts of power - since 1 HP is about 740 watts of power, then you would be drawing about .047 HP from your motor. When the load changes to 11 amps, then you would be drawing 11x7=77 watts and your HP draw would be .104 from the motor. You might ask - why not set the generator to put out 15 amps exactly as is its max? The problem is that your ammeter cannot be counted upon to be that accurate and in the event you only need a small amount of power for awhile - your generator will be racing to put that power all back at the rate of 15 amps when there is no big hurry to do so. This running of the generator at max when not necessary results in shorter generator and generator brush life and more heat from the generator, since you would be running it at 105 watts whenever the battery needs charge - like when you first start up the car during the daylight hours; which is, for the most part, what constitutes more than half of your batteries discharge. Longest life occurs when you match the source power to the load demanded and let the battery fill in the gaps with its enormous reserve capacity of 60 to 80 amp hours.
Unlike turning on the headlights to reduce charging, as was done in the old days, using your new VR does not work that way. The VR literally shuts the generator down so it produces less power; but when the battery calls for max charge, because it is down a bit, the VR has to let the generator go to its 3rd brush adjusted "max" and that is the adjustment you are making [moving the 3rd brush to zero the ammeter when the lights are on].
It may be hard for you to wrap your head around the idea that the VR is in fact controlling the generator since you see only the one connection from the armature to the VR, like the cutout; but, the VR can easily CONTROL the generators field current and thus control the generators output. It does this by passing signals back through the armature that, then, only the field will respond to. Some say "impossible to control something unless you are wired to it"; but, I would point out that your remote control for your TV is not wired to it, yet it controls everything about it. The highway for TV control is either UV light or RF. The highway for Generator control is the Armature winding and knowing how to do it."
While not necessarily done in the same way, it sounds like the FP EVR and the Wesenberg EVR (based on your description of that device in the article) operate under the same basic principle.
For whatever this is worth...
Respectfully,
