Dual switchover
With the legs firing in turn through their load resistors, how far does each pulse charge this cell, what does the supply deliver, and does anything build up against the water's leak?
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.
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C Cell capacitance 452.7 pF
One sphere-in-sphere of Spherical - 2x Series 2" & 4" — 2 in inside 4 in — in distilled / deionised at 20 °C.
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C Cell capacitance 226.4 pF
2 such cells in series. The array calculation's inductance is a placeholder for its resonance figure; the capacitance does not depend on it.
Multi-cell array — 2 notes on that page
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ℓ Cell leak resistance 500 kΩ
Leak resistance assumed at 500 kΩ: the water's conductivity is not known. Open the bare-numbers page to set it yourself.
- No water chosen, so the cell is taken as full of distilled water at 20 °C. Pick a water to change that.
Result
How far one leg's pulse charges the cell from empty.
The on-time less the dead time.
The instant a leg closes.
Charge per pulse times the rate.
What the supply delivers.
Where the cell voltage stands after n pulses against the leak.
Fraction of the cell voltage surviving to the next pulse.
LaTeX
100\,\mathrm{V} = 100\,\mathrm{V} \left( 1 - e^{-490\,\mathrm{µs} / (1000\,\mathrm{Ω} \cdot 226.4\,\mathrm{pF})} \right)
Worth knowing
- 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 10% of what perfect retention would give. Raising the drive frequency shortens the gap between pulses and helps; raising the water resistance helps far more.
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
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One leg's pulse: how far the cell charges through the load resistor, and what that costs the supply.
With these numbers LaTeX
0.2264\,\mathrm{µs} = 1000\,\mathrm{Ω} \cdot 226.4\,\mathrm{pF} \qquad 100\,\mathrm{V} = 100\,\mathrm{V} \left( 1 - e^{-490\,\mathrm{µs} / 0.2264\,\mathrm{µs}} \right) \qquad 22.64\,\mathrm{nC} = 226.4\,\mathrm{pF} \cdot 100\,\mathrm{V} \qquad 22.64\,\mathrm{µA} = 22.64\,\mathrm{nC} \cdot 1\,\mathrm{kHz} \qquad 2.264\,\mathrm{mW} = 100\,\mathrm{V} \cdot 22.64\,\mathrm{µA} -
2. Step charging accumulation
U 100 VWhether those pulses accumulate against the water's leak between them, or each starts from nothing.
With these numbers LaTeX
113.2\,\mathrm{µs} = 500\,\mathrm{kΩ} \cdot 226.4\,\mathrm{pF} \qquad 0.000146 = e^{-1000\,\mathrm{µs}/113.2\,\mathrm{µs}} \qquad 100\,\mathrm{V} = 100\,\mathrm{V} \cdot \frac{1 - 0.000146^{10}}{1 - 0.000146}- 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 10% of what perfect retention would give. Raising the drive frequency shortens the gap between pulses and helps; raising the water resistance helps far more.
What this looks like
The formula behind the curve
- U
- Cell voltage after one pulse, V
- V
- Supply voltage, V
- e
- Effective on-time, µs
- R
- Load resistor, Ω
- C
- Cell capacitance, nF
LaTeX
U = V \left( 1 - e^{-e / (R \cdot C)} \right)
The formula behind the curve
- U
- Cell voltage after one pulse, V
- V
- Supply voltage, V
- e
- Effective on-time, µs
- R
- Load resistor, Ω
- C
- Cell capacitance, nF
LaTeX
U = V \left( 1 - e^{-e / (R \cdot C)} \right)
Open the bare numbers — the same simulation on its own page, every derived value editable.