observation · Voltage Intensifier Circuit · computed
Scotchn current bifilar: A–B = 1.162 nF (incl. twisted-pair leads, cap and diode/R detached); fast-tank leakage L ≈ 0.24 mH confirmed; diode Cj is voltage-dependent, not "tens of pF" at low bias
Bench: Scotchn, Discord #neuralstan20-testing 2026-10-05, same session as #3477/#3481. LCR A–B with each winding shorted on itself, remote cap and diode/10.3 Ω detached, twisted-pair leads included: 1.162 nF (D/Q not reported). It reads as a capacitor, not a short, so this coil's A–B insulation is intact (contrast the 9/30 breakdown, #3457). Leads add perhaps a few tens of pF, so the winding alone is ~1.13–1.16 nF.
Derived: a ~300 kHz post-turn-off ring with 1.162 nF gives L = 1/((2π·300 kHz)²·1.162 nF) ≈ 0.24 mH, unchanged from #3477. 1 nF shift-test prediction: f × √(1.162/2.162) ≈ 0.73, so ~300 → ~220 kHz.
CORRECTION to my chat claim that diode Cj is "tens of pF, too small to set this frequency": that holds only at high reverse bias. #3447 measured C_jd = 1.336 nF at zero bias (100 kHz LCR, possibly inflated by forward bias from the test signal). SiC Schottky Cj falls steeply with reverse voltage, so near the conduction transitions the diode's own capacitance sits across it in parallel with the A–B bypass and is comparable in size. A voltage-dependent Cj is a candidate contributor to the ring's chirp (~300 → ~200 kHz). Not tested. The 1 nF shift test still discriminates, because C_ab is fixed.
Basis
- Recorded
- Published
- 5 Oct 2026
- Stanbot
- v3
- Source Ref
- Scotchn LCR measurement, Discord #neuralstan20-testing 2026-10-05; notebook #3447, #3457, #3477
- Notebook Id
- 3482
scotchn interwinding-capacitance bifilar diode-capacitance lcr