@ Ufopolitics and @ Ifarrand,

Thank You all for Your excellent guidance & clarity

We are now building a completely custom physical system with:
Unconventional magnetic topology
Unique switching requirements
Safety-critical timing
Bidirectional propulsion behavior
Real hardware already in hand

REMARK:
There is no off-the-shelf reference design for this project
Yes, and getting all the details aligned now prevents:
Wasting hardware
Chasing false failures
Damaging expensive switches
Mis-interpreting test results
Doubting a design that is actually solid

We handled the misalignment exactly right: by calling it out directly, but respectfully.

The best engineering breakthroughs happens exactly like this: through transparent collaboration.
This is engineering at its best.

I am honored to help to do it right.
Alex

Hello All,

@kampen, many thanks for the kind words!
Now, below is Your Wiring Diagram Setup for the 13 Sequential Coils, as per my suggestions on my prior post...all in just one image:



ALL SERIES COILS are connected on the back of bus connectors bar. (So, NO JUMPERS HERE)
NO Diodes, No snubbers, no capacitors or condensers, no BPS's connected here...
JUST PLAIN WIRES TO WIRES...and as SHORT as you can make them, as shown on Diagram...Clean.

EDIT 1: ALL 13 COILS MUST BE wound and ALIGNED on the SAME DIRECTION !!
So TERMINAL#1 on NFET BANK is the START of COIL#1...As the END of COIL#1 CONNECTS with the START of #2 Coil...and so on and on...until it ENDS at COIL#6 at the PFET BANK, where END of COIL#6 goes to TERMINAL#7 of PFET BANK.

Cheers

Ufopolitics

Quote from: Ufopolitics on Oct 27, 2025, 02:37 AM[...]
Hello All,

I have made the below Diagram, so a full context is understood, and BASED ON GROUPS from G1 to G7:

As the objective is to show a Test that should be conducted, before starting the System Sequences.

And that is to measure independently the Resistance of each Group, of course, it just need to be done once, from G1 to G7, HOWEVER, the connections to FET's must be removed, not to get any false resistance readings.

So, on the case of Kampen 13 Coils, he has each sequential coil approximately at 6.0 Ohms each. (more or less, we do not need to be that accurate here)

Each Group have Seven (7) Coils, so the Total Resistance should be near the 42.0 Ohms.

On the Diagram [G1-R1] means Group One (1) have a Resistance R1...And it would be to set a Resistance Meter between both same number terminals (#-1 & #+1)

And at the end, ALL RESISTANCES for each Group MUST BE AROUND THE SAME Resistance Value...

Or the "IDEAL" goal is that : R1=R2=R3=R4=R5=R6=R7= 42.0 +/- Ohms

To be more precise, we could measure first each coil resistance to see if all are around the 6.0 Ohmsvalue...it don't matter if one is 6.25 while the other is 6.10...

Once the System starts warming up, plus reaching the running frequency, it will start a process of "equalization"...

But, this test will make sure we do not have any wrong connections...eg: by having one group with six (6) coils and next with seven...this will show on the TOTAL RESISTANCE between them.

As if ALL RESISTANCES PER EACH GROUP are around the same value, this will guarantee we will have the SAME AMPERAGE, HENCE THE SAME FIELD STRENGTH during the Sequencing.

Regards

Ufopolitics

Hello All, hello dear friend Kampen,

The above quoted post, I did it a few days ago, before we were 'not connected' related to topologies application and testing...so, while you were testing based on single coil pulsing...I was relating to Groups (Topology 1).

However, this is an IMPORTANT TEST to make BEFORE you Test RUN the System, based on Topology 1.

And that is to test each Group Resistance, from Group 1 to Group 7, while having ALL FET BOARDS DISCONNECTED (not to get false resistance reading interference with connected electronic components.

So, again, your Single Coil Resistance is around 6.0 Ohms, and each Group have Seven (7) Coils, therefore the TOTAL RESISTANCE PER GROUP SHOULD BE NEAR THE 42.0 Ohms (6.0ohms X7 Groups=42 Ohms)


On above image I am Checking the Resistance 1 on Group 1, with a Resistance Meter (Note ALL FET BOARDS ARE DISCONNECTED)


As above image I am checking Group 7 Total Resistance.

ALL GROUPS MUST RESULT IN ABOUT THE SAME (OR APPROXIMATE) RESISTANCE VALUE, OR 42.0 OHMS

This will serve to check if all our connections are well,  ( For Example: IF Total Resistance in  a Group results in 30 Ohms, THEN, SOMETHING IS DEFINITIVELY WRONG!!) as also to confirm that we will be running with around the same Resistance, which means the same Currents (Amperage) meaning SAME FIELD STRENGTH.

Regards

Ufopolitics

@ Ufopolitics

Thanks for the clarification, and this diagram helps a lot for all.
All 13 coils wired in series only,
directly to the rear bus connector bar, no jumpers, no diodes, no snubbers, no capacitors, no BPS components.
Just clean point-to-point wiring with minimum length, exactly like your diagram shows.

Coil winding direction must be identical for all coils.
Start → End direction must remain consistent across the entire sequence.
So the connections go:
NFET Bank Terminal #1 → START of Coil #1
 END of Coil #1 → START of Coil #2
 END of Coil #2 → START of Coil #3
 ... continuing straight through ...
 END of Coil #6 → PFET Bank Terminal #7
Center coil labeled C is included in the same continuous direction and alignment with the rest.

Everything is now crystal clear, and thanks again for the update!
If there are any additional phasing or polarity checks required before power-up, just let me know.

Conclusion
Wiring order: Correct
 Series chain: Correct
 NFET left / PFET right: Correct
 No jumpers / no snubbers: Matches design intent

From the diagrams you provided, everything appears properly aligned with the intended 13-coil Kampen drive sequence.
Alex

In other news, the parts for the 14 driver boards have shipped, but it seems there is a delay at UPS (probably related to the UPS cargo plane that crashed).



There's also a decision to be made. I came across this guide by Recom (the DC/DC transformer manufacturer), which explains how to modify a +15V/-3V transformer to output +18V/0V.

QuoteInfineon has recently released the new M1H series of SiC Mosfets. With this generation, Infineon recommends a different gate-source drive voltage than that used with their other series or those used by other manufacturers. The recommended turn-off voltage is zero volts, and the turn-on voltage is close to +18V.

The absolute maximum gate drive voltage limits are -7/+23V.

The standard R-REF01-HB design could be used to evaluate these transistors using the included +15/-3V DC/DC converter (R12P21503D). However, the M1H transistors would not operate when fully enhanced. So, although the existing layout would work, compared to the recommended +18V gate-source voltage, there would be significantly more conduction losses.

RECOM's DC/DC power supplies are very flexible. Instead of using the +15 /-3V asymmetric outputs, you can use the same DC/DC converter to generate a single-ended 18V supply. However, as the R-REF01-HB was designed to work with a dual supply, you would need to make some minor modifications to the board.

This might be a better fit for the MOSFETs we've chosen.




Please also consider these graphs. With +15V the MOSFET doesn't fully turn on as quick as +18V or +20V, which means it will spend more time in the 'ohmic region' and cause it to heat up. This also means power will be wasted, so switching losses will increase.



@kampen - What would you like to do? Stick with +15V/-3V, or go with +18V/0V?