900VA Tesla Coil


900VA Tesla Coil
Content © 2004-2017 ALH unless otherwise stated.


900VA Tesla Coil

(July 15, 2007)
On December 29, 2000, I bought this 15kv/60ma neon Franceformer for $149 to make a Jacob’s Ladder at 14 years old. Before I completely finished my tabletop tesla coil, I thought “Wouldn’t it be nice to utilize something I have lying around.” So I did. Cap bank is 0.0075uF@39kv made from 18 of those cheap $1 oil caps at Alltronics.com. If I run it too long, the caps get a little warm, but no big deal. If I want long run times, I can just use more. Spark gap is made of 7 6” long 0.5” stainless steel pieces of pipe. The gap quencher is just a microwave fan that blows toward itself and the gap. Primary is 17.75 turns of 1/4” diameter insulated limp wire spliced into some harder wire for the taps, tapped at 14.67. Secondary is 4” PVC (4.5” OD) with a winding length of 19.5” of 25 AWG wire coated with polyurethane–970 turns (I counted as I went). Topload is two toroids of 3” aluminum ducting coated with aluminum tape with the bottom diameter of 10” and the top diameter of 15”. It produces 24”-35” sparks.