Tesla Coil


AC Input:
Just an extension cord and a power strip for now.

HV Transformer:
7.5KV 60 MA neon sign transformer 450W.

HV Transformer protection:
Only one RF choke 1.27mH

Spark gap:
A 3-segment static gap, spaced 0.056" each for a total of 0.17", airflow through spark gaps provided by a 3" fan.

Tank Capacitor:
One Maxwell Technologies Cap rated at 35KVDC @ 0.03uF with an inductance of 0.02uH

Primary coil:
6.75 turns max flat spiral 0.162" solid copper ground wire, 1/4" gap between turns, 5.75" ID, 12" OD.

Secondary coil:
2.375"D x 12.75"L (approx 1010 turns) 28 AWG wound on 1/8" wall dried/sealed PVC pipe. Coated with many layers polyurethane. Self-resonant with no topload at 712 kHz. C-self = 5.1 pF. With 3.375" x 11.5" toroid (12.5 pF), Fr is 380 kHz.

Discharge terminal:
Small 3.375" x 11.5" toroid made from aluminum flex duct, stiffened and smoothed with spakel, covered with aluminum tape.

Ground system:
One 6 foot ground rod in earth, connected with three 16Awg wire.

Performance to date:
Max sparks to grounded target (grounded threaded rod): 22"

email me at
if you have any question or any tips.
last updated 09/28/02

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