Subjecf Re: Bipolar vs MOSFET Switching Clarifying the Stepping Ladder

Dear friend Ufopolitics,

Great question and thanks for raising it, because this is exactly where terminology can get crossed.

It is not too early to tell anymore, based on the mechanical commutator drawings you shared.

The short answer is:
Yes, MOSFETs are still the correct switching devices.

What changes is how they are organized and controlled.
When I previously mentioned a "stepping ladder," I was not implying that MOSFETs were no longer suitable. 
The "ladder" refers to the State-Machine Logic and Sequencing that replaces the mechanical commutator and not to a resistor ladder or non-MOSFET switching topology.
From the Bipolar Mechanical Commutator behavior we now understand:

• The system does reverse polarity every half-cycle
• This means the solid-state equivalent must behave like a Bipolar Switch
• Electrically, that translates to an H-bridge topology
• Practically, that still uses MOSFETs, arranged as complementary pairs with enforced deadtime

So:

• The system is bipolar in function
• But MOSFETs are the correct and preferred devices to implement it
• The "stepping ladder" is the 32-State Sequencing Logic that steps through the commutation states, emulating the mechanical overlap and break-before-make behavior.

Nothing here excludes MOSFETs in fact, the architecture we are converging on is exactly what modern Motor-Control and commutator-replacement designs use.
So the answer is:

• Bipolar behavior: Yes, required
• MOSFET switching: Yes, absolutely
• Stepping ladder: logical/state sequencing, not a different power device

Thanks again for your dedication to the project the mechanical clarity you provided is what allowed this to lock into place.

Regards, Alex