[BC] 12 phase

[PeterH5322@aol.com]

>Ok, I gotta ask. where did the other 9 phases come from?

Three-phase half-wave gives you three pulses per cycle, and requires 
three rectifiers, total.

Three-phase full-wave gives you six pulses per cycle, and requires six 
rectifiers, total.

Three-phase full-wave zig-zag gives you twelve pulses per cycle, and 
requires twelve rectifiers, total.

"The other nine phases" should probably read "the other six phases", 
where the term "phases" is very loosely used, as all of these systems are 
actually three-phase, period.

The three basic phases are 0, 120 and 240 degrees.

For full-wave, 0-180, 120-180 and 240-180 degrees are also used.

This is where 180, 300 and 60 degrees comes from, thereby providing 0, 
60, 120, 180, 240, and 300 degrees.

"Twelve-phase" is really three-phase full-wave, with the 30 degree pulse 
being formed by vector addition of the 0 and 60 degree pulses, etcetera.

So, to answer your specific question, the SIX other phases came from the 
process described in the immediately preceding paragraph, repeated over 
those six extra phases.

All are really three-phase, however.

These are inaccurately, but traditionally called three-phase, "six-phase" 
and "twelve-phase".