[rotorwrench]

Like most folks that fabricate electronic components like this, their design is a proprietary information that they can pick and choose who has access to it. John Reagan and Tom Wesenberg plus a few others made their units to sell for profit so they were and are also responsible for the function of same and any implied warranty. A person can see why they might not make their design public information.

Tom's unit had a diode to protect it from reverse current but some folks wanted to use either a cut out or a diode in the cut out can. John Reagan's unit was in the diode can along with his own diode but the Fun Projects chip became obsolete so it is no longer produced by the folks that bought out his design. His unit still used the 3rd brush but it had to be current output adjusted to his specs for it to function properly.

If a person tries to reverse engineer this stuff, they may run into the same problem of obsolescence. Electronics repair folks have to have the information on what new electrical component to replace any obsolete stuff they might run up against in older designs. If one person can make one then so can another as long as they have a good idea how to control voltage output and current for a 3-brush generator.

James Peterson is another fellow associated with 3-brush controllers. His is similar to Tom's unit but I don't know if he still makes them. His info is on Vince's model A & B Ford Garage site.