Reply to message # 724 Ufopolitics

Hello my dear friend Ufopolitics,

Yes, your interpretation is essentially correct.
In my simplified 4-coil transition concept, the idea was indeed:
✔ keep one positive-side selector active during the transition interval
 ✔ use the return-side selectors to shape the conduction window
 ✔ maintain current continuity through make-before-break overlap

So during the overlap region:

• the incoming return selector ramps ON
• while the outgoing return selector ramps OFF
• and the active positive selector remains energized long enough to prevent interruption of the conduction path.

This was intended to create a smooth "sliding current exposure" instead of abrupt commutation.

Your blank timing framework is actually extremely useful because it expands the view from:
👉 "single transition event"
to:
👉 "full coil exposure versus time"
which is much clearer for understanding the behavior of the whole chain.
I also agree that visualizing:

• Q1
• Q2
• Q3
• Q4

against:

• SL0
• SL1
• SR2
• SR3

with explicit overlap (OL) regions will make the timing relationships much easier to validate before hardware testing begins.

Especially important is that your diagram starts revealing:
✔ effective coil dwell time
 ✔ overlap duration
 ✔ exposure symmetry
 ✔ whether the center region remains continuously energized
This becomes extremely relevant now that we are evolving toward the 5-coil / 3-window architecture.
 
So yes, my next step will be to generate a complete timing map showing:

• full-cycle gate sequencing
• selector states
• coil ON/OFF exposure
• overlap windows
• transition timing progression for the entire sequence.

I believe this will help greatly before we proceed with the physical switching validation.

Thank you again for your careful observations and for helping refine the timing model into a much more understandable framework.

Regards, my friend,
 Alex

Complete Timing Map — 5-Coil / 3-Coil-Window SSD Setup

Updated topology:
 N0 — Q1 — N1 — Q2 — N2 — Q3 — N3 — Q4 — N4 — Q5 — N5
Selector Groups
·G1 = SL0 + SR3 → Q1 + Q2 + Q3 ON
·G2 = SL1 + SR4 → Q2 + Q3 + Q4 ON
·G3 = SL2 + SR5 → Q3 + Q4 + Q5 ON
Full Cycle Sequence
G1 → G1/G2 overlap → G2 → G2/G3 overlap → G3 → G3/G2 overlap → G2 → G2/G1 overlap → G1

1. Selector State Table

Step	Phase	SL0	SL1	SL2	SR3	SR4	SR5	Active coils
1	G1 stable	ON	OFF	OFF	ON	OFF	OFF	Q1 Q2 Q3
2	G1→G2 overlap	ramp ↓	ramp ↑	OFF	ramp ↓	ramp ↑	OFF	Q1 Q2 Q3 Q4
3	G2 stable	OFF	ON	OFF	OFF	ON	OFF	Q2 Q3 Q4
4	G2→G3 overlap	OFF	ramp ↓	ramp ↑	OFF	ramp ↓	ramp ↑	Q2 Q3 Q4 Q5
5	G3 stable	OFF	OFF	ON	OFF	OFF	ON	Q3 Q4 Q5
6	G3→G2 overlap	OFF	ramp ↑	ramp ↓	OFF	ramp ↑	ramp ↓	Q2 Q3 Q4 Q5
7	G2 stable	OFF	ON	OFF	OFF	ON	OFF	Q2 Q3 Q4
8	G2→G1 overlap	ramp ↑	ramp ↓	OFF	ramp ↑	ramp ↓	OFF	Q1 Q2 Q3 Q4
9	G1 stable	ON	OFF	OFF	ON	OFF	OFF	Q1 Q2 Q3

2. Coil Exposure Map

TIME →        G1      OL12      G2      OL23      G3      OL32      G2      OL21      G1

SL0           ON       ↓        OFF      OFF       OFF      OFF      OFF       ↑       ON
SL1           OFF      ↑        ON       ↓         OFF      ↑        ON        ↓       OFF
SL2           OFF      OFF      OFF      ↑         ON       ↓        OFF       OFF     OFF

SR3           ON       ↓        OFF      OFF       OFF      OFF      OFF       ↑       ON
SR4           OFF      ↑        ON       ↓         OFF      ↑        ON        ↓       OFF
SR5           OFF      OFF      OFF      ↑         ON       ↓        OFF       OFF     OFF

Q1            ON       fade↓    OFF      OFF       OFF      OFF      OFF       fade↑   ON
Q2            ON       ON       ON       fade↓     OFF      fade↑    ON        ON      ON
Q3            ON       ON       ON       ON        ON       ON       ON        ON      ON
Q4            OFF      fade↑    ON       ON        ON       ON       ON        fade↓   OFF
Q5            OFF      OFF      OFF      fade↑     ON       fade↓    OFF       OFF     OFF


Key point: Q3 remains continuously energized through the full sequence.

3. Transition Timing Model
Incoming selector duty: D_in = t / T_OL
Outgoing selector duty: D_out = 1 - (t / T_OL)

4. Simplified Functional Movement

G1: Q1 Q2 Q3
        ↓
G2:    Q2 Q3 Q4
        ↓
G3:       Q3 Q4 Q5
        ↓
G2:    Q2 Q3 Q4
        ↓
G1: Q1 Q2 Q3


5. Recommended Starting Timing Values
·Stable dwell time: 1000–2000 ms
·Overlap transition: 500–1000 ms
·PWM ramp steps: 50–100 steps
·Start duty limit: 30–50%
·Current limit: 0.3–0.5 A

6. Critical Validation Targets
·No open circuit during transitions
·No sudden current collapse
·No excessive voltage spikes
·Center coil Q3 remains continuously energized
·Smooth make-before-break overlap behavior

Regards, Alex

To proceed to the next step need to update the platform to the 5-coil / 3-coil-window version. 
This is the better Small-Scale build.

Updated topology
N0 — Q1 — N1 — Q2 — N2 — Q3 — N3 — Q4 — N4 — Q5 — N5
Active groups:
G1: SL0 + SR3 → Q1 + Q2 + Q3
G2: SL1 + SR4 → Q2 + Q3 + Q4
G3: SL2 + SR5 → Q3 + Q4 + Q5
This gives a true center-coil effect at Q3.
Updated required parts list
Coil / mechanical section

Part	Spec	Qty
Primary bobbins	Your square bobbins	5
PA6 square core	Horizontal mechanical core	1
Clamp brackets	Nylon / PA6	5 sets
Primary coils	Target 8 Ω each	5
Tap terminals	N0–N5	6
Base plate	HDPE / acrylic / FR4	1
Magnet wire	Gauge to be calculated for 8 Ω/coil	as needed

Selector/driver section

Part	Spec	Qty
Selectors	SL0, SL1, SL2, SR3, SR4, SR5	6
N-channel MOSFETs	2 per selector, back-to-back	12
UCC21220 driver boards	2 channels per board	3
Isolated 12 V supplies	Ideally one per selector/channel	6
Gate resistors	10 Ω	12
Gate pulldown resistors	10 kΩ	12
Gate-source zeners	12–15 V	12
Screw terminals	For selectors and nodes	as needed
For your 5-coil / 6-selector SSD setup, I recommend: Best practical choice IRLB3036PBF, N-channel MOSFET, Logic-level gate, Vds: 60 V, Very low Rds(on), TO-220 package Avoid Do not buy IRFZ44N for this if you can avoid it.  You want IRL, not IRF.

Controller

Part	Spec	Qty
Arduino Uno Rev3	6 PWM outputs available	1
USB cable	USB-B	1
Jumper wires	Arduino to drivers	set

Arduino pin map:
D3  → SL0
D5  → SL1
D6  → SL2
D9  → SR3
D10 → SR4
D11 → SR5
Power/measurement

Part	Spec	Qty
Bench PSU	0–30 V or higher, current-limited	1
Multimeter	Resistance/current checks	1
Oscilloscope	2–4 channel minimum	1
Current probe	DC capable preferred	1
Hall sensors	Optional field mapping	3–5
Thermometer/thermocouples	Coil heating	1 set

Target electrical values
Primary coils:
Each coil: 8 Ω
Each active group: 3 coils × 8 Ω = 24 Ω
Operating points:
12 V / 24 Ω = 0.5 A
24 V / 24 Ω = 1.0 A
36 V / 24 Ω = 1.5 A
Start only at:
12 V, 0.3–0.5 A limit
Do NOT start at 36 V. At 36 V, each coil dissipates about ca. 18 W,
so that should only be short-pulse testing.
Step-by-step build plan
Step 1 — Redesign platform layout
Use 5 bobbins instead of 4:
Q1 — Q2 — Q3 — Q4 — Q5
Keep spacing small and equal. If possible, reduce spacing compared with the earlier 25 mm gap.
Step 2 — Calculate wire gauge before winding
Do not wind yet until the wire resistance is planned.
Goal:
8 Ω per primary coil
Measure or estimate the average turn length around your bobbin, then calculate turns/wire gauge.
The wire choice matters more now than before.
Step 3 — Wind the 5 primary coils
For all coils:
same direction
same turns
same resistance
same lead orientation
After winding, measure:
Q1 = __ Ω
Q2 = __ Ω
Q3 = __ Ω
Q4 = __ Ω
Q5 = __ Ω
Accept only if they are close, ideally within ±5%.
Step 4 — Build coil chain only
Wire:
N0 — Q1 — N1 — Q2 — N2 — Q3 — N3 — Q4 — N4 — Q5 — N5
Measure:
N0 to N5 ≈ 40 Ω
Step 5 — Build one selector and test it alone
One selector = two MOSFETs back-to-back + one UCC21220 channel.
Test with a small lamp/resistor first, not the coils.
Step 6 — Build all 6 selectors
Selector mapping:
SL0: +V → N0
SL1: +V → N1
SL2: +V → N2
 
SR3: N3 → GND
SR4: N4 → GND
SR5: N5 → GND
Step 7 — Static group tests
Test one group at a time:
G1: SL0 + SR3
G2: SL1 + SR4
G3: SL2 + SR5
Confirm that only the correct 3 coils are energized.
Step 8 — Transition testing
Use make-before-break:
G1 → G2:
SL1 + SR4 ramp up
SL0 + SR3 ramp down
 
G2 → G3:
SL2 + SR5 ramp up
SL1 + SR4 ramp down
Then reverse:
G3 → G2 → G1
Step 9 — Add secondaries later
Do not add secondaries during the first switching tests.
After the primaries work correctly, add:
end secondary left: ~1 Ω
main secondary: ~2 Ω
end secondary right: ~1 Ω
Then connect secondaries in series as Ufopolitics suggested.
Best next action
Before ordering more wire, measure one bobbin and decide:
target resistance: 8 Ω
available winding space
average turn length
desired wire gauge
Then calculate the correct wire gauge/turn count. This is the most important next step.

Regards, Alex

Subject Ref.: Preliminary Wire Length and 8 Ohm Coil Calculations Small-scale Setup

Hello dear Ufopolitics,

I have prepared some preliminary wire length and bobbin dimension calculations for the small-scale SSD coil setup, targeting approximately 8 Ω per coil. 

I am attaching the diagrams and calculation references for your review.
The calculations are based on the current bobbin dimensions:

• Outer size: 53 × 53 mm
• Inner window: 39 × 39 mm
• Core / former size: 44.7 × 44.7 mm
• Winding width: 18.7 mm
• Radial winding allowance: approximately 4.15 mm per side
• Estimated Mean Turn Length (MTL): approximately 195.4 mm per turn

Using these dimensions, I estimated the required wire lengths and approximate turns count for several wire gauges from AWG30 through AWG33 in order to reach roughly 8 Ω resistance per coil.

From the preliminary calculations, AWG30–AWG32 appear to be the most practical starting range. 
The estimated turns remain mechanically manageable while staying well within the available winding space.

I also included:

• Approximate wire length required for each gauge
• Estimated turns count
• Layer estimation
• Approximate radial build for fit verification

Of course, these are still theoretical calculations, and the final practical winding resistance may vary slightly depending on:

• Actual enamel thickness
• Winding tension
• Packing density
• Temperature
• Real measured copper resistance

My recommendation would be to wind one test coil first and measure resistance progressively every 10–20 turns until reaching the desired target value.

Please take a look at the attached calculations and let me know if you agree with this approach and the dimensional basis before proceeding further.

Kind regards,
 Alex

Hello All,

Hello dear friend Kampen,

Sorry I could not respond to your request before, I have been very busy lately.

It is great that you liked my proposal of five (5) coils, as you already started all the pre-design! BUT, please hold on to your design...as I have noticed too narrow design on your sequential spools!!

It would be a great small platform to test on different possibilities to search for the best outcome.

And yes, we should consider a small input for primaries as is 12 Volts at 0.5 Amps.


There would be Three Groups of Three Coils each, where ALL are connected in Series.

There would be Three Positive Trigger Points (red arrows) as Three Negative (return) Trigger Points (black arrows)


So, yes, in order to keep a low currents of half amp at 12 Volts we will need a total of around 24 Ohms per Group of Three (3) Coils, meaning 8.0 Ohms per each coil.

However, that is keeping all coils symmetrically distributed per the same resistance each.

But, since we have a Center Coil (Q3) which is always ON during the sequencing...we could use this coil to play in an Asymmetrical way.

And what I mean is to either reduce or increase the resitance on this particular coil...so:

• Let's say if we Reduce the Center Coil resistance to 6 Ohms, then we need to Increase resistance on all other Four Coils, in order that the sum of every Three Coils will Total the required 24 Ohms per group, then each Coil needs increasing to 9.0 Ohms (9+9+6=24)
• Or we could Increase the Center Coil Resistance to 10 Ohms, and decrease the resistance on each coil to 7.0 Ohms (7+7+10=24)

Now, since this Center Coil stays ON at ALL time, if we reduce its resistance it will tend to overheat, plus the rest of the other Four Coils by having more resistance will have a delayed time to respond.

Then the more favorable option would be to Increase the Center Coil Resistance, as lowering resistance on the other Four Coils equally.

From the Magnetic Field perspective, the Main and Stronger portion of the Field would be at the exact center of the steel core.
Then the Field 'extensions' would be the Two Coils at each sides from the center Coil, where their response would be much faster on high frequency operation.

The downside of doing this Asymmetrical Resistance on Increasing the Center Coil, would be that the chances of switching coils to increase their reverse spikes whenever turned OFF. will be higher.

However, the changes I have done above are NOT TOO RADICAL, as we are just playing in resistance variations of just Two (2) Ohms.


Ok, so since we are reducing the number of sequential coils to a Minimum of just Three (3) per Group, then we need WIDER Coils,in order that they will expand the Field in LENGTH making the Field 'jumps' Spatially Larger.

At the same token, it will allow more room to add the main secondary, without Increasing in Height (This is a very important part to have in mind!)

Basically, because the sequential coils need to be as close as possible to the steel core to increase the Inducing Field Strength over their Secondaries.

And believe me that changing the positioning of the Coils , like setting all sequential coils directly on steel core, then adding the Main Secondary on TOP...WILL NOT WORK!

I have tried that possibility, and does not work.

The Main Secondary needs to be "sandwiched" between sequentials on TOP, and Main Secondary underneath on the Steel Core!!

Concluding that ALL Sequential Coils (Four here, since Center does not suffer any pulsed sequence, by being ON all the time) needs to be build much wider than on the Fifteen Coils setup We previously built.

The rule is:

• The lesser coils we use as the sequential the WIDER they need to be.
• As the more coils we add to the sequence, the NARROWER they need to be built.

However, the CENTER Coil could be NARROWER on this Five (5) Coils Model than the Four (4) Sequential coils, and the advantages would be:

• Allowing more room to be built WIDER for the other four coils at each side of center.
• Concentrating the Center Portion of Field on a shorter Spatial Volume.
• Creating Larger Linear Travel of the displacing Field.

FINALLY about the Sequential Coil's Gauge I would use 28 gauge

With 28 gauge we will reach the 8.0 Ohms per coil with approximately from 114 ft to 129 ft (see image below of the CIRRUS  Wire Calculator on line:


The advantages to experiment with a smaller scale prototype is that we could test many possibilities to see which one results on a better outcome, without the need to rewind so many sequential coils on a larger scale model.

Now, what I recommend FIRST to use the Conventional SYMMETRICAL Resistance distribution method. Test and write down all Output Results from ALL Three (3) Secondaries.

Then, and only then, we could change to the ASYMMETRICAL Resistance distribution, obviously by INCREASING Center Coil resistance as reducing the other Four Coils...then compare Output Results with the Symmetrical way we previously tested.

Regards

Ufopolitics