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Stan’s Legacy

8XA - 6x Parallel Joe Cell

High capacity 6-cell parallel spherical array.

From the archive's library.

The parts

The drive no drive was saved with it; these are the engine's defaults

kHz

The pulse frequency the loop is driven at.

V

The peak voltage applied across the loop — after the transformer, if there is one.

%

How much of each pulse period the drive is on.

Hz

The slow gate switching the pulse train on and off.

%

How much of each gate period the pulses are let through.

Separate, or on one core with fields aiding or opposing.

How much of one choke's flux threads the other. Zero for separate cores.

From the parts

Every number handed to the simulation that you did not type, and where it came from. Each derivation that ran a calculation links to that calculation's page with these numbers in, so it can be checked alone.

  • σ On the way 0.7813 µS/cm

    Distilled Water's conductivity, from its dissolved solids reading.

    Dissolved solids to conductivity

  • L₁ Charging choke 137.5 µH

    The charging choke's inductance: 100 turns on Ferrite Toroid T130-2 (μᵣ 10, 0.36 cm², 3.29 cm path).

    Inductance of a winding on a core

  • L₂ Blocking choke 137.5 µH

    The blocking choke's inductance: 100 turns on Ferrite Toroid T130-2 (μᵣ 10, 0.36 cm², 3.29 cm path).

    Inductance of a winding on a core

  • R Series resistance 0.2423 Ω

    Series resistance, added up: Negative Choke - 100 Turns AWG18 0.0962 Ω + Negative Choke - 100 Turns AWG18 0.0962 Ω + Spherical - 6x Parallel (High Cap) 0.05 Ω. Wiring and connections are not counted.

  • C Cell capacitance 443.7 pF

    One sphere-in-sphere of Spherical - 6x Parallel (High Cap) — 2 in inside 4 in — in distilled / deionised at 25 °C.

    Concentric-sphere cell capacitance

  • C Cell capacitance 2.662 nF

    6 such cells in parallel. The inductance handed to the array calculation is the two chokes added plainly, for its resonance figure only; the capacitance does not depend on it.

    Multi-cell array — 2 notes on that page

  • Cell leak resistance 3.342 kΩ

    The leak across one sphere, from its geometry and Distilled Water at 0.781 µS/cm. 6 such cells in parallel leak 6 times as readily, so this is one 6th of that.

    Leak resistance across a spherical cell

Result

f₀ Resonant frequency 186 kHz

Where the loop — both chokes and the cell — actually rings. Compare with the drive frequency.

L Loop inductance 275 µH

Both chokes together, with the mutual term if they are coupled.

M Mutual inductance 0 mH

Signed: positive aiding, negative opposing, zero if independent.

Z Characteristic impedance 321.4 Ω

√(L/C) — what the loop looks like at resonance before resistance.

Q Q factor 1327

How sharp the resonance is against the series resistance.

U Resonant rise 15.92 kV

The cell voltage at resonance — Q times the drive.

ζ Damping ratio 0.000377

Below 1 the loop rings after each pulse; above 1 it sags.

τ Decay time constant 2.27 ms

How fast the ring dies away.

I Peak current 2.013 mA

What the drive pushes at the drive frequency, not at resonance.

W Average power 0.2455 µW

Dissipated in the resistance, averaged over pulses and gate.

n Pulses per gate 50

How many pulses arrive before the gate closes.

S Staircase peak 12 V

Where the step-charge staircase tops out against the leak, after n pulses.

With your numbers
186kHz=12π275µH·2.662nF
LaTeX
186\,\mathrm{kHz} = \frac{1}{2\pi \sqrt{275\,\mathrm{µH} \cdot 2.662\,\mathrm{nF}}}

Worth knowing

  • Q factor and voltage rise — A Q of 1327 is very high for a circuit with water in it, and implies a bandwidth of only 140.2 Hz. Confirm the series resistance includes the cell’s own losses — using just the choke’s winding resistance is the usual way to arrive at a Q like this on paper and not on the bench.
  • Current and power under a pulsed drive — The drive is at 0.05× the loop's resonance (186 kHz). The net reactance of -5.96 kΩ is what limits the current here, not the resistance; on resonance the same drive would push 49.5 A.
  • Step charging accumulation — Only 0% of the voltage survives between pulses, so there is no staircase — each pulse is very nearly starting from nothing. The cell is discharging through the water faster than it is being charged.
  • Step charging accumulation — The burst reaches 2% of what perfect retention would give. Raising the drive frequency shortens the gap between pulses and helps; raising the water resistance helps far more.
  • The drive is at 10 kHz and the loop rings at 186 kHz — 0.05× resonance. The resonant rise of 15.9 kV above is what this loop would do driven on resonance; at the drive frequency the cell sees the drive through -5.96 kΩ of reactance instead. Either move the drive or change a choke so the two agree.

This result is a link — the address bar holds your numbers, so it can be pasted into a post and opened to the same answer.

The working, step by step

  1. The drive as timing: how long each pulse is, how many fit inside one gate, and what fraction of the time the drive is on.

    With these numbers
    100µs=110kHz50µs=100µs·50%10050=50%100·10kHz100Hz25%=50%·50%100
    LaTeX
    100\,\mathrm{µs} = \frac{1}{10\,\mathrm{kHz}} \qquad 50\,\mathrm{µs} = 100\,\mathrm{µs} \cdot \frac{50\,\mathrm{%}}{100} \qquad 50 = \left\lfloor \frac{50\,\mathrm{%}}{100} \cdot \frac{10\,\mathrm{kHz}}{100\,\mathrm{Hz}} \right\rfloor \qquad 25\,\mathrm{%} = \frac{50\,\mathrm{%} \cdot 50\,\mathrm{%}}{100}

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  2. 2. Two chokes on one core

    L 275 µH

    The two chokes as the loop sees them — their sum, plus or minus the mutual term if they share a core.

    With these numbers
    0mH=±0137.5µH·137.5µH275µH=137.5µH+137.5µH+2·0mH137.5µH=137.5µH+0mH
    LaTeX
    0\,\mathrm{mH} = \pm 0 \sqrt{137.5\,\mathrm{µH} \cdot 137.5\,\mathrm{µH}} \qquad 275\,\mathrm{µH} = 137.5\,\mathrm{µH} + 137.5\,\mathrm{µH} + 2 \cdot 0\,\mathrm{mH} \qquad 137.5\,\mathrm{µH} = 137.5\,\mathrm{µH} + 0\,\mathrm{mH}

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  3. Where that inductance and the cell ring.

    With these numbers
    186kHz=12π275µH·2.662nF
    LaTeX
    186\,\mathrm{kHz} = \frac{1}{2\pi\sqrt{275\,\mathrm{µH} \cdot 2.662\,\mathrm{nF}}}

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  4. How sharply, against everything resistive in the loop, and how far the cell voltage rises above the drive on resonance.

    With these numbers
    1327=10.2423Ω275µH2.662nF15.92kV=1327·12V
    LaTeX
    1327 = \frac{1}{0.2423\,\mathrm{Ω}}\sqrt{\frac{275\,\mathrm{µH}}{2.662\,\mathrm{nF}}} \qquad 15.92\,\mathrm{kV} = 1327 \cdot 12\,\mathrm{V} \qquad 140.2\,\mathrm{Hz} = \frac{186\,\mathrm{kHz}}{1327}
    • A Q of 1327 is very high for a circuit with water in it, and implies a bandwidth of only 140.2 Hz. Confirm the series resistance includes the cell’s own losses — using just the choke’s winding resistance is the usual way to arrive at a Q like this on paper and not on the bench.

    Open this step on its own page, with these inputs

  5. 5. Damping and ringdown

    ζ 0.000377

    What happens after each pulse: whether the loop rings or sags, and for how long.

    With these numbers
    0.000377=0.2423Ω22.662nF275µH2.27ms=2·275µH0.2423Ω186kHz=12π1275µH·2.662nF12.27ms2972.2=ln10π·10.2423Ω275µH2.662nF
    LaTeX
    0.000377 = \frac{0.2423\,\mathrm{Ω}}{2} \sqrt{\frac{2.662\,\mathrm{nF}}{275\,\mathrm{µH}}} \qquad 2.27\,\mathrm{ms} = \frac{2 \cdot 275\,\mathrm{µH}}{0.2423\,\mathrm{Ω}} \qquad 186\,\mathrm{kHz} = \frac{1}{2\pi} \sqrt{\frac{1}{275\,\mathrm{µH} \cdot 2.662\,\mathrm{nF}} - \frac{1}{2.27\,\mathrm{ms}^{2}}} \qquad 972.2 = \frac{\ln 10}{\pi} \cdot \frac{1}{0.2423\,\mathrm{Ω}} \sqrt{\frac{275\,\mathrm{µH}}{2.662\,\mathrm{nF}}}

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  6. What the drive is asked for at the frequency it actually runs at — which is the resonance only if the two agree.

    With these numbers
    -5.961=2π10kHz·275µH12π10kHz·2.662nF5.961=0.2423Ω2+-5.96122.013mA=12V5.9610.9818µW=2.013mA2·0.2423Ω0.2455µW=0.9818µW·25%1000.04909nJ=0.9818µW·50µs
    LaTeX
    -5.961\,\mathrm{kΩ} = 2\pi 10\,\mathrm{kHz} \cdot 275\,\mathrm{µH} - \frac{1}{2\pi 10\,\mathrm{kHz} \cdot 2.662\,\mathrm{nF}} \qquad 5.961\,\mathrm{kΩ} = \sqrt{0.2423\,\mathrm{Ω}^{2} + -5.961\,\mathrm{kΩ}^{2}} \qquad 2.013\,\mathrm{mA} = \frac{12\,\mathrm{V}}{5.961\,\mathrm{kΩ}} \qquad 0.9818\,\mathrm{µW} = 2.013\,\mathrm{mA}^{2} \cdot 0.2423\,\mathrm{Ω} \qquad 0.2455\,\mathrm{µW} = 0.9818\,\mathrm{µW} \cdot \frac{25\,\mathrm{%}}{100} \qquad 0.04909\,\mathrm{nJ} = 0.9818\,\mathrm{µW} \cdot 50\,\mathrm{µs}
    • The drive is at 0.05× the loop's resonance (186 kHz). The net reactance of -5.96 kΩ is what limits the current here, not the resistance; on resonance the same drive would push 49.5 A.

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  7. The pulse train against the cell and its leak: does the charge accumulate into a staircase, or drain away between pulses?

    With these numbers
    8.896µs=3.342·2.662nF1.313e-5=e100µs/8.896µs12V=12V·11.313e-55011.313e-5
    LaTeX
    8.896\,\mathrm{µs} = 3.342\,\mathrm{kΩ} \cdot 2.662\,\mathrm{nF} \qquad 1.313e-5 = e^{-100\,\mathrm{µs}/8.896\,\mathrm{µs}} \qquad 12\,\mathrm{V} = 12\,\mathrm{V} \cdot \frac{1 - 1.313e-5^{50}}{1 - 1.313e-5}
    • Only 0% of the voltage survives between pulses, so there is no staircase — each pulse is very nearly starting from nothing. The cell is discharging through the water faster than it is being charged.
    • The burst reaches 2% of what perfect retention would give. Raising the drive frequency shortens the gap between pulses and helps; raising the water resistance helps far more.

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What this looks like

Resonant frequency against cell capacitance Cell capacitance swept from 1.33 nF to 3.99 nF with everything else held at your numbers. The dashed lines cross where you are.
Resonant frequency against cell capacitanceResonant frequency falls from 263 kHz to 152 kHz as cell capacitance rises from 1.33 nF to 3.99 nF. At your cell capacitance of 2.66 nF it is 186 kHz.15017520022525027512342.66 nF186 kHzCell capacitance (nF)Resonant frequency (kHz)
The formula behind the curve
f₀=12πL·C
f₀
Resonant frequency, Hz
L
Loop inductance, mH
C
Cell capacitance, nF
LaTeX
f₀ = \frac{1}{2\pi \sqrt{L \cdot C}}
What moves the answer Each input moved 10% either way, with the others held still, and the effect on resonant frequency.
What moves the answerResonant frequency is most sensitive to Cell capacitance, which moves it by about 5.41% for a 10% change. It is least sensitive to Cell leak resistance, at about 0%.Change in the answer when each input moves by 10%-10%-5%5%10%Cell capacitance±5.41Charging choke±2.6Blocking choke±2.6Coupling coefficient±0Series resistance±0Drive frequency±0Drive amplitude±0Pulse duty±0Gate frequency±0Gate duty±0Cell leak resistance±0
The formula behind the curve
f₀=12πL·C
f₀
Resonant frequency, Hz
L
Loop inductance, mH
C
Cell capacitance, nF
LaTeX
f₀ = \frac{1}{2\pi \sqrt{L \cdot C}}

Open the bare numbers — the same simulation on its own page, every derived value editable.