PREFERRED charging method (Chris Freedom build): inductive boost / energy-packet step charging, which gets past the diode's 2V − V₀ ceiling

Adopted by Chris Freedom as his preferred method (Discord #neuralstan20-testing, 2026-09-29), paper stage. Choke-geometry tweaks deferred.

PROBLEM: in series resonant charging (voltage source V, blocking diode), a cell already at V0 can only reach 2V − V0. Once the cell is at 2V the diode stays reverse-biased and nothing more gets in. Reflection or Q "stacking" is capped at R/Z0 = (1+Γ_L)/(1−Γ_L) by the water leakage.

KEY PRINCIPLE: the diode blocks a VOLTAGE source, not a CURRENT source. A choke carrying current raises L·di/dt to whatever it needs to push that current into the cell. Each release delivers ½LI² at any cell voltage. Precedents: the collapsing-field "double pulse" in US 4,936,961, and radar line-type modulators, where the charging choke's collapsing field is what carries the PFN to 2× supply and a De-Q switch stops it at a set energy (radartutorial.eu). The way past 2V is to make the choke carry more current at turn-off.

TOPOLOGY (derived design, NOT a Stan schematic): secondary → D1 → choke L1 → node X → D2 → cell (→ L2 → return), with a controlled switch S from node X to return. S on: current ramps in L1 with no opposing cell voltage. S off: L1 dumps through D2 into the cell. Voltage grows as √n (n = packet count), lossless.

NUMBERS (VIC5 C1 choke, Don Gabel: 1.2 H, 76.7 Ω; ideal 60 V secondary, which is an UPPER BOUND since k ≤ 0.42): I(1 ms) ≈ 48 mA, E ≈ 1.4 mJ/packet, one packet takes 2.5 nF from 0 to ≈1.06 kV. 5 kV (31 mJ) ≈ 22 packets with zero leakage. A coated cell has lower C, so each packet gives more volts.

CAVEATS: (1) a clamp is mandatory (spark gap, TVS stack or De-Q path); boost into an open or arcing load has no ceiling. (2) S sees the full cell voltage when off, so it must be a controlled switch (stacked SiC), or the scheme moves to the primary side as a VIC5 flyback. (3) The staircase stops where leakage (Fig 8 current) equals energy per packet, so the insulated electrodes still set the ceiling. (4) S must turn off while the secondary is still driving (inside T1). If T1 ends first, the transformer reset opposes the dump. (5) L2 sits in the dump path and changes the transfer; include it later.

DIODE CHOICE (Chris): Sanken UX-F5B, 8 kV VRM, 350 mA IF(av), VF 11–14 V, trr ≤ 0.15 µs. Suits D2, and D1 (after the dump, node X sits near cell voltage, so D1 also needs a kV rating). It CANNOT be S: a diode cannot be commanded on. Its 11–14 V VF in D1 costs about 20 % of a 60 V charging drive.